Abstract
Condensed Abstract: Cancer is the second leading cause of death among Chamorros, the indigenous population of Guam, yet little has been published about cancer control needs of this population. This paper provides important data about Chamorro’s knowledge, attitudes and screening behaviors that can help to guide a comprehensive cancer control program on Guam.
Background
Cancer is the second leading cause of death among Chamorros, the indigenous population of Guam. This study assessed cancer related knowledge, attitudes, and preventive behaviors (KAB) among Chamorros on the island.
Methods
We conducted a self-administered English language survey regarding cancer-related KAB using a non-probability purposive sample design in 266 self-identified Chamorros (149 women and 117 men) over the age of 50 years. The survey included demographics; health status; access to medical care; and KAB about breast, cervical, prostate, colorectal, lung, and nasopharyngeal cancer. Descriptive statistics and bivariate analysis were used to assess the data.
Results
Overall, 83.3% of women reported having a mammogram and 62.8% reported having a Pap smear within the past two years. Only 20.3% of men reported having a prostate specific antigen (PSA) test within the past year. Of concern, only 43.1% had heard of PSA. Only 38.3% of participants reported ever having fecal occult blood testing, 15.5% ever having sigmoidoscopy, and 33.1% ever having colonoscopy. Respondents who had a regular source of care were more likely to receive up to date mammography screening (p<0.01). Likewise, those who had visited their doctor within the past year were more likely to be screened for breast (p<0.01), cervical (p<0.05), prostate (p<0.01), and colorectal cancer (p<0.05). In addition, residents living in the south were less likely to report screening for breast (p<0.05), prostate (p<0.05), and colorectal (p<0.01) cancer.
Conclusion
These results provide important data about Chamorro’s KAB that can help to guide a comprehensive cancer control program on Guam.
Keywords: cancer, cancer prevention and control, cancer screening, special populations, Chamorros
INTRODUCTION
Cancer is the second only to cardiovascular disease as the leading cause of death in the United States (US) (1). While much progress has been made regarding the prevention, early detection and treatment of this disease, not all ethnic groups have benefited. Pacific Islanders, in particular, have only recently been the focus of studies regarding cancer control, and some of the findings have been disturbing. For example, we now know that Native Hawaiians have the highest incidence of breast cancer of any ethnic group in the US (2).
In the study reported herein, we describe the results of the first comprehensive evaluation of cancer related knowledge, attitudes, and preventive behaviors (KAB) of Chamorros, the indigenous population of Guam. Before describing the study, it is important to describe the island of Guam, the Chamorro people, traditional health beliefs, the medical care system, and the importance of cancer in this population.
Guam, Micronesia’s largest island, is located approximately 1,550 miles south of Japan. Except for a brief period during World War II, Guam has been under the administrative jurisdiction of the US since the end of the Spanish American War in 1889. In 1950, the Organic Act of Guam deemed the island a civilian territory and the residents US citizens. Guam is a major tourist destination in the western Pacific. In addition, it is home to important US military facilities including naval and air force bases. The island is divided into three main regions; the northern, central, and southern. The regions contain 19 villages that are governed by Mayors. The northern portion of the island is controlled by the US military, the central area contains most of the tourist resorts, and the southern section is the most remote.
Chamorros are the most populous ethnic group on Guam, making up 37% of the population, and the third most populous Pacific Islander group living in the US (3). According to the 2000 Census, 398,835 “Native Hawaiians and other Pacific Islanders” lived in the US. Of these, 140,652 were Native Hawaiian, 91,029 were Samoan, and 58,240 were Guamanian/Chamorro. In addition, 154,805 Guamanians/Chamorros lived on the US Territory of Guam. Ethnic groups other than Chamorros on the island include Filipinos (26%), Asians (13%), non-Latino Whites (6.8%), and Micronesians other than Chamorro (8%). Chamorros are, on average, young (25.4 years, compared to the national U.S. average of 33 years) and have large families (3.9 persons) (3). Most Chamorros speak English fluently and have adopted western-style behaviors.
Traditionally, Chamorros believed that illness had either natural or spirit causes and that rapport and respect must exist with the taotaomona (ancient spirits of the island) (4). If this rapport was not maintained illness could occur. Chamorros sought health care from suruhana (female) and suruhanu (male) healers. The traditional healing methods involved medicinal remedies using natural plants, roots and flowers as well as mystical body lotions, dietary advice, massage, and a curing power. Over the years, these cultural beliefs and practices have blended with American values, and today Chamorros often use both Western physicians and traditional healers (5).
Western style medical care on Guam is provided by a civilian hospital, the Guam Memorial Hospital Authority, three public health clinics, and private practitioners and clinics (6). The island has a Breast and Cervical Cancer Screening Program supported by the Centers for Disease Control and Prevention. The program pays for screening for uninsured and underinsured women but does not cover confirmatory work up or treatment if cancer is found. The Cancer Institute of Guam (CIG), a private practice physician group, provides specialized cancer care including chemotherapy. Until the facilities were destroyed by a typhoon in 2002, CIG also offered radiation therapy services. Since then, patients have been sent off island for this care. Likewise, many cancer-related diagnostic tests are sent off island for evaluation. A recent assessment of the cancer control on Guam identified, among other things, the need for training for health care professionals in chemotherapy, palliative care and other treatment of identified cancers (6).
Cancer is the second leading cause of death for all residents of Guam including Chamorros (7). The age adjusted incidence rates for cancer of all sites for Chamorros (200.64 per 100,000) is lower than that of the general US population (249.65 per 100,000). The most common cancers among Chamorro women are breast cancer followed by colorectal and lung cancer. The same cancers are the leading causes of cancer death in women with lung cancer being first followed by breast and colorectal cancer. The most frequently diagnosed cancers and cancers causing mortality among Chamorro men are lung cancer followed by prostate, colorectal, and nasopharyngeal cancer.
In this study, we evaluated cancer related KAB in Chamorros residing on Guam with particular emphasis on the use of cancer screening services. The study is important for several reasons. First of all, very little information exists about cancer control in this indigenous population and the availability of comprehensive screening has been suspect. Second, based upon findings in other indigenous Pacific Islander populations, we anticipated limited knowledge about cancer and low levels of screening for the disease. Finally, to improve cancer control, it is important to understand what Chamorros know about the disease and its early detection and treatment.
MATERIALS AND METHODS
We conducted a self-administered English language survey regarding cancer-related KAB among 266 (149 women and 117 men) self-identified Chamorros over the age of 50 years on the island of Guam in the summer of 2004. The University of California, Irvine Human Subjects Review Committee approved the study protocol.
Research Design, Sampling Strategy, and Data Collection
A non-probability purposive sample design was used to recruit the participants (8). To ensure participation of residents from each region of the island, we randomly selected 11 villages (of a total of 19) from three distinct regions: three villages from the northern, four from the central, and four from the southern regions. With the assistance of the Mayors’ offices (the traditional center of governance), we distributed and posted flyers and made announcements inviting residents within each selected village to participate. Participants were invited to various locations across these 11 villages where they completed the self-administered survey. Trained Chamorro interviewers were available at the meetings to answer questions. The survey took approximately 30 minutes to complete. No incentives were provided; however participants were invited to partake in a traditional Chamorro meal.
Survey Instrument
In preparation for the survey, we consulted the Pacific Islander Cancer Control Network Guam advisory board (9) to determine the cancers of most interest. We also conducted a series of focus groups with Chamorro residents representing each of the three regions to determine knowledge and attitudes about cancer that might be unique to this population. In brief, the findings revealed that there was great concern about cancer and its impact on Chamorros. Some participants believed that exposure to radiation from nuclear testing carried by the trade winds from the Marshall Islands to Guam was a major cause of cancer. Most participants did not believe that taotaomona caused cancer or that suruhanas should treat cancer.
The survey instrument contained questions derived from the focus group findings, the National Health Interview Survey (NHIS) and the NHIS Cancer Control Supplement (10,11). We asked detailed questions about cancer in general and about breast, cervical, and prostate cancer – cancers in which the community advisory boards were particularly interested. We also asked a limited number of questions about other common cancers among Chamorros: colorectal, lung, and nasopharyngeal cancer. The survey included questions concerning knowledge about risk factors, utilization of cancer screening and early detection exams, family resources (health insurance coverage, employment status, and family income), and demographic characteristics. The attitudinal questions measured important concepts in cancer control such as beliefs about the importance of early detection and prevention of cancer and fear of the disease. The knowledge and attitude questions employed a 4-point Likert scale and don’t know responses (12). As a measure of acculturation, we modified an acculturation scale that has been widely used among Latinos (13).
Statistical Analysis
We used descriptive statistics and bivariate analysis to assess the data. When assessing the knowledge and attitude variables, we dichotomized the 4-point Likert scale from “Strongly Disagree,” “Disagree,” “Agree,” “Strongly Agree” to “Disagree” vs. “Agree”. Demographic characteristics and medical care access measures were the predictor variables in the bivariate analyses. Self-reported use of cancer screening tests [mammography, Pap smear, prostate specific antigen (PSA), fecal occult blood test (FOBT), sigmoidoscopy, and colonoscopy] was the outcome variable.
RESULTS
Demographic characteristics for the entire population (N=266) are described below. Table 1 displays these demographic characteristics by gender. The majority of participants were born on Guam (97%). Approximately three fourths of the sample reported having high school or more education. Over 68% of the sample was married and the majority was either employed (32.9%) or retired (49.8%). About one fifth of the respondents reported having a household income less than $25,000. Only a small proportion (18.3%) reported that they spoke Chamorro better than English.
Table 1.
Variable | Male (n=117)* | Female (n=149)* |
---|---|---|
Age | 107 | 137 |
50–59 | 47 (43.9) | 69 (50.4) |
60–69 | 39 (36.4) | 36 (26.3) |
70 and older | 21 (19.6) | 32 (23.4) |
Marital Status | 116 | 148 |
Married | 90 (77.6) | 90 (60.8) |
Separated/Divorced/Widowed | 20 (17.2) | 42 (28.4) |
Never married | 6 ( 5.2) | 16 (10.8) |
Education | 104 | 145 |
Less than high school | 17 (14.8) | 33 (22.8) |
High school graduate | 55 (47.8) | 60 (41.4) |
More than high school | 32 (37.4) | 52 (35.9) |
Household Income | 104 | 122 |
<25,000 | 20 (19.2) | 37 (30.3) |
25–50,000 | 34 (32.7) | 34 (27.9) |
>50,000 | 50 (48.1) | 51 (41.8) |
Did not answer | ||
Have Health Insurance | 116 | 146 |
Yes | 102 (87.9) | 117 (80.1) |
No | 14 (12.1) | 29 (19.9) |
Type of Health Insurance | ||
Government | 46 | 49 |
Medicaid | 3 ( 6.5) | 2 ( 4.1) |
Medicare | 22 (47.8) | 33 (67.3) |
Military (VA, Champus) | 20 (43.5) | 12 (24.5) |
Medical Indigent Program | 1 ( 2.2) | 2 ( 4.1) |
Private | 114 | 141 |
Yes | 77 (67.5) | 95 (67.4) |
No | 37 (32.5) | 46 (32.6 |
Employment Status | 110 | 139 |
Employed | 32 (29.1) | 50 (36.0) |
Retired | 75 (68.2) | 49 (35.3) |
Unemployed | 3 ( 2.7) | 40 (28.8) |
Language Spoken | 116 | 141 |
Chamorro better | 26 (22.4) | 21 (14.9) |
Both equally | 80 (69.0) | 93 (66.0) |
English better | 10 ( 8.6) | 27 (19.1) |
Language Read | 115 | 142 |
Chamorro better | 4 ( 3.5) | 4 ( 2.8) |
Both equally | 35 (30.4) | 54 (38.3) |
English better | 76 (66.1) | 83 (58.9) |
Region of Residence | 114 | 142 |
North | 39 (34.2) | 55 (38.7) |
Central | 40 (35.1) | 48 (33.8) |
South | 35 (30.7) | 39 (27.5) |
Family Size | 115 | 144 |
Single resident | 11 ( 9.6) | 21 (14.6) |
Couple/Cohabitation | 33 (28.7) | 39 (27.1) |
Three or more | 71 (61.7) | 84 (58.3) |
The total numbers reflect the number of respondents who answered the question regarding each variable. Not all respondents answered each question. Percentages may not total up to 100 due to rounding errors.
Approximately 30% of respondents lived in the southern part of the island. As described below, living in this area was predictive of lower use of several cancer screening tests. Compared with residents of the north and central regions, these individuals were poorer, less likely to be employed, more likely to speak Chamorro, and more likely to travel for greater than 30 minutes to receive health care (p<0.05 in each case) (data not shown).
Measures of health status and access to medical care appear in Table 2. Of note, the majority (71.8%) of respondents reported excellent, very good, or good health. The majority of respondents had a regular source of medical care (92.8%), with the most common site being a doctor’s office, and had visited their regular source of care within the past year (81.3%). Approximately one third of participants had received care off island at some time in their lives.
Table 2.
Variable | Total N(%)* |
---|---|
Health Status | 263 |
Excellent | 18 ( 6.8) |
Very good | 59 (22.4) |
Good | 112 (42.6) |
Fair | 66 (25.1) |
Poor | 8 ( 3.0) |
Have a regular source of care | 264 |
Yes | 245 (92.8) |
No | 19 ( 7.2) |
Type of regular source of care | 204 |
Doctor’s office | 111 (44.6) |
Emergency room | 3 ( 1.2) |
Hospital outpatient clinic | 28 (11.2) |
Health center | 38 (15.3) |
Public health clinic | 4 ( 1.6) |
Other | 20 (8.0) |
Last visit to health care | 252 |
Less than 1 year ago | 205 (81.3) |
1–2 years ago | 29 (11.5) |
2–3 years ago | 8 ( 3.2) |
More than 3 years ago | 10 ( 4.0) |
Ever received healthcare off-island | 265 |
Yes | 88 (33.2) |
No | 177 (66.8) |
The total numbers reflect the number of respondents who answered the question regarding each variable. Not all respondents answered each question. Percentages may not total up to 100 due to rounding errors.
The results regarding knowledge and attitudes about cancer in general appear in Table 3. The respondents were unlikely to believe that cancer was caused by taotamonas (2.7%) or that suruhanos could treat cancer (7.7%). Only a small proportion (3.8%) reported they would go to a suruhano for treatment of cancer; however, approximately one third had visited a suruhano for some type of medical care.
Table 3.
Variables | Total N(%) | |
---|---|---|
Would rather not know if I had cancer | 261 | |
Disagree | 161 (61.7) | |
Agree | 85 (32.6) | |
Don’t know | 15 (5.7) | |
Cancer is caused by taotamonas# | 263 | |
Disagree | 226 (85.9) | |
Agree | 7 ( 2.7) | |
Don’t know | 30 (11.4) | |
Cancer is punishment from God | 260 | |
Disagree | 232 (89.2) | |
Agree | 12 ( 4.6) | |
Don’t know | 16 ( 6.2) | |
At this age, I do not worry about cancer | 263 | |
Disagree | 200 (76.0) | |
Agree | 48 (18.3) | |
Don’t know | 15 ( 5.7) | |
Cancer is spread through air | 265 | |
Disagree | 160 (60.4) | |
Agree | 64 (24.2) | |
Don’t know | 41 (15.5) | |
Faith in God will cure cancer | 232 | |
Disagree | 72 (27.4) | |
Agree | 169 (64.3) | |
Don’t know | 22 ( 8.4) | |
Cancer is brought by foreigners | 263 | |
Disagree | 198 (75.3) | |
Agree | 32 (12.2) | |
Don’t know | 33 (12.5) | |
Faith in God will protect me from getting cancer | 232 | |
Disagree | 123 (48.8) | |
Agree | 97 (38.5) | |
Don’t know | 32 (12.7) | |
Neglecting health causes cancer | 262 | |
Disagree | 97( 37.0) | |
Agree | 152 (58.0) | |
Don’t know | 13 ( 5.0) | |
God empowers doctors to cure cancer | 260 | |
Disagree | 96 (36.9) | |
Agree | 139 (53.5) | |
Don’t know | 25 ( 9.6) | |
I would get cancer treatment that is unpleasant if it improves my chances of living longer | 259 | |
Disagree | 46 (17.8) | |
Agree | 189 (73.0) | |
Don’t know | 24 ( 9.3) | |
Cancer is caused by environment | 262 | |
Disagree | 53 (20.2) | |
Agree | 172 (65.6) | |
Don’t know | 37 (14.1) | |
Having a blood relative who has had cancer puts me at risk for cancer | 269 | |
Disagree | 87 (33.0) | |
Agree | 149 (56.4) | |
Don’t know | 28 (10.6) | |
Cancer is caused by smoking | 264 | |
Disagree | 36 (13.6) | |
Agree | 212 (80.3) | |
Don’t know | 16 ( 6.1) | |
Cancer is caused by diet, the types of food you eat | 263 | |
Disagree | 57 (21.7) | |
Agree | 182 (69.2) | |
Don’t know | 24 ( 9.1) | |
Ever gone to a suruhano+ for health care | 158 | |
Yes | 92 (35.7) | |
No | 166 (64.3) | |
Can a suruhano+ treat cancer? | 155 | |
Yes | 12 ( 7.7) | |
No | 143 (92.3) | |
If I get cancer, I would seek treatment by a suruhano+ | 263 | |
Disagree | 236 (89.7) | |
Agree | 10 ( 3.8) | |
Don/t know | 17 ( 6.5) |
The total numbers reflect the number of respondents who answered the question regarding each variable. Not all respondents answered each question. Percentages may not total up to 100 due to rounding errors.
Taotamonas: ancient spirits
Suruhano: traditional healer
Breast Cancer
Of the breast cancer risk factors evaluated, the women were most likely to agree that family history (54.1%) and high fat diet (54.5%) increased risk and least likely to believe that early menses (8.8%) did so (Table 4). It is noteworthy that approximately 30% of women acknowledged that loss of breast due to cancer would have a significant negative effect on their relationship.
Table 4.
Variables | Total N (%) | |
---|---|---|
Getting older increases chance of breast cancer | 145 | |
Disagree | 65 (44.8) | |
Agree | 59 (40.7) | |
Don’t Know | 21 (14.5) | |
Diet high in fat increases chance of breast cancer | 143 | |
Disagree | 35 (24.5) | |
Agree | 78 (54.5) | |
Don’t Know | 30 (21.0) | |
Giving birth after age 30 increases chance of breast cancer | 141 | |
Disagree | 77 (54.6) | |
Agree | 23 (16.3) | |
Don’t Know | 41 (29.1) | |
Relative with breast cancer increases risk | 146 | |
Disagree | 48 (32.9) | |
Agree | 79 (54.1) | |
Don’t Know | 19 (13.0) | |
Using birth control pills increases risk | 145 | |
Disagree | 38 (26.2) | |
Agree | 55 (37.9) | |
Don’t Know | 52 (35.9) | |
Exposure to X-rays increases risk | 144 | |
Disagree | 39 (27.1) | |
Agree | 63 (43.8) | |
Don’t Know | 42 (29.2) | |
Starting menses before age 12 increases risk | 147 | |
Disagree | 79 (53.7) | |
Agree | 13 (8.8) | |
Don’t Know | 55 (37.4) | |
How important are breasts to feel like a woman | 143 | |
Very important | 104 (72.7) | |
Somewhat important | 27 (18.9) | |
Not important | 12 (8.4) | |
Would loss of breasts affect relationship | 105 | |
A lot | 33 (31.4) | |
Somewhat | 20 (19.0) | |
Very little | 52 (49.5) | |
Would loss of breast affect sexual relationship | 98 | |
A lot | 32 (32.7) | |
Somewhat | 15 (15.3) | |
Very little | 51 (52.0) |
The total numbers reflect the number of respondents who answered the question regarding each variable. Not all respondents answered each question. Percentages may not total up to 100 due to rounding errors.
Table 5 reports knowledge about and use of breast cancer screening methods. The large majority of respondents had heard of breast self examinations (94.6%), clinical breast exams (87.1%), and mammography (100%). The large majority (94.4%) also knew that mammograms could detect breast cancer early; and 43% expressed fear that the mammogram would detect breast cancer. Only a minority of respondents reported problems with barriers to mammogram screening such as lack of child support (7%) or transportation (8.0%), knowing where to get the test (17%), or needing help arranging it (15.6%). Moreover, 47% reported examining their breast once per month, 63.6% reported having a clinical breast exam within the past year, and 83.3% reported having a mammogram within the past 2 years. In the bivariate analysis, having health insurance (p<0.05), having a regular source of care ((p<0.01), and having an ambulatory visit within the past year (p<0.01) were associated with increased self-reported mammogram use within the past two years whereas living in the southern part of Guam was associated with decreased use (p<0.05). Having a regular source of care was associated with ever having a mammogram ((p<0.01).
Table 5.
Variables | N(%) | TOTAL* | |
---|---|---|---|
Heard of a breast self-exam | Yes | 139 (94.6) | 147 |
No | 8 ( 5.4) | ||
Know how to check for lumps in your beasts | Yes | 134 (96.4) | 139 |
No | 5 ( 3.6) | ||
How often do you examine your breasts | Once a month | 63 (47.0) | 134 |
< once a month | 70 (52.3) | ||
Never | 1 ( 0.7) | ||
Heard that doctors should examine breasts | Yes | 121 (87.1) | 139 |
No | 18 (12.9) | ||
Have you had a doctor examine your breasts | Yes | 134 (98.5) | 136 |
No | 2 ( 1.5) | ||
Last time a doctor examined your breasts | Within last 12 months | 84 (63.6) | 132 |
Between 1–2 years ago | 31 (23.5) | ||
> 2 years ago | 17 (12.9) | ||
Heard of mammogram | Yes | 148 (100) | 148 |
No | 0 (0) | ||
Mammogram can detect cancer early | Disagree | 5 ( 3.5) | 141 |
Agree | 134 (94.4) | ||
Don’t Know | 2 ( 2.1) | ||
A mammogram may be painful | Disagree | 47 (31.8) | 148 |
Agree | 95 (64.2) | ||
Don’t Know | 6 ( 4.1) | ||
Afraid a mammogram may find breast cancer | Disagree | 75 (52.4) | 143 |
Agree | 62 (43.4) | ||
Don’t Know | 6 ( 4.2) | ||
Embarrassed when getting mammogram | Disagree | 125 (85.6) | 146 |
Agree | 18 (12.3) | ||
Don’t Know | 3 ( 2.1) | ||
Difficult to take time to get mammogram | Disagree | 116 (80.6) | 144 |
Agree | 25 (17.4) | ||
Don’t Know | 3 ( 2.1) | ||
Difficulty to find caregivers for child or older person | Disagree | 126 (88.7) | 142 |
Agree | 10 ( 7.0) | ||
Don’t Know | 6 ( 4.2) | ||
Need more information on what, where, and how to get a mammogram | Disagree | 112 (79.44) | 141 |
Agree | 24 (17.0) | ||
Don’t Know | 5 ( 3.5) | ||
Need help arranging mammogram | Disagree | 116 (82.3) | 141 |
Agree | 22 (15.6) | ||
Don’t Know | 3 ( 2.1) | ||
Difficult to get transportation to get mammogram | Disagree | 127 (92.0) | 138 |
Agree | 11 ( 8.0) | ||
Ever had a mammogram | Yes | 142 (96.6) | 147 |
No | 5 ( 3.4) | ||
Most recent mammogram | Within last 12 months | 70 (50.7) | 138 |
Between 1–2 years ago | 45 (32.6) | ||
Between 2–5 years ago | 17 (12.3) | ||
>5 years ago | 6 ( 4.3) |
The total numbers reflect the number of respondents who answered the question regarding each variable. Not all respondents answered each question. Percentages may not total up to 100 due to rounding errors.
Cervical Cancer
Table 6 displays cervical cancer related knowledge and attitudes. Over half of the participants responded that factors related to sexual activities such as having multiple sexual partners (56.8%) and having a sexually transmitted virus (59%) increased risk for the disease. However, 45.8% also thought that having a family history of cervical cancer was a risk factor.
Table 6.
Variables | N (%)* |
---|---|
Sex at early age increases risk of cervical cancer | 143 |
Disagree | 62(43.4) |
Agree | 35(24.5) |
Don’t Know | 46(32.2) |
Smoking increases risk of cervical cancer | 141 |
Disagree | 48(34.0) |
Agree | 57(40.4) |
Don’t Know | 36(25.5) |
Having multiple sex partners increases risk of cervical cancer | 139 |
Disagree | 23(16.5) |
Agree | 79(56.8) |
Don’t Know | 37(26.6) |
Blood relative with cervical cancer increases risk | 142 |
Disagree | 47(33.1) |
Agree | 65(45.8) |
Don’t Know | 30(21.1) |
Having sexually transmitted virus increases risk | 144 |
Disagree | 15(10.4) |
Agree | 85(59.0) |
Don’t Know | 44(30.6) |
The total numbers reflect the number of respondents who answered the question regarding each variable. Not all respondents answered each question. Percentages may not total up to 100 due to rounding errors.
Results regarding knowledge about cervical cancer screening appear in Table 7. Of note, the large majority knew that a Pap smear could detect cervical cancer early (81.7%) and had heard of the human papillomavirus (68.1%). Few experienced difficulty taking time to get a Pap smear (13.4%) or needed to have more information about how to obtain a Pap smear (9.7%). All but one woman (99.3%) reported having a Pap smear ever, 35.8% within the past year, 62.8% within the past two years, and 84% within the past five years. The bivariate analysis revealed that younger women (50–69 years) (p<0.001), those with household incomes of more than $25,000 per year (p<0.05), and those who had an ambulatory visit within the past year (p<0.05) were more likely than others to reported having a Pap smear within the past two years.
Table 7.
Variables | N(%)* |
---|---|
Heard of Pap smear | 148 |
Yes | 146 (98.6) |
No | 2 ( 1.4) |
Pap smear can detect cancer early | 131 |
Disagree | 107 (81.7) |
Agree | 13 ( 9.9) |
Don’t Know | 11 ( 8.4) |
Have ever heard of human papillomavirus | 135 |
Yes | 30 (22.2) |
No | 92 (68.1) |
Don’t Know | 13 ( 9.6) |
Pap smear would be painful | 143 |
Disagree | 79 (55.2) |
Agree | 60 (42.0) |
Don’t Know | 4 ( 2.8) |
Concerned Pap smear may find cervical cancer | 145 |
Disagree | 57 (9.3) |
Agree | 81 (55.9) |
Don’t Know | 7 ( 4.8) |
Embarrassed when getting Pap smear | 146 |
Disagree | 93 (63.7) |
Agree | 49 (33.6) |
Don’t Know | 4 ( 2.7) |
Difficult to take time to get Pap smear | 142 |
Disagree | 119 (83.8) |
Agree | 19 (13.4) |
Don’t Know | 4 ( 2.8) |
Difficulty to find caregivers for child or older person | 143 |
Disagree | 125 (87.4) |
Agree | 6 ( 4.2) |
Don’t Know | 12(8.4) |
Need more information on what, where, and how to get a Pap smear | 144 |
Disagree | 123(85.4) |
Agree | 14(9.7) |
Don’t Know | 7(4.9) |
Ever had a Pap smear | 144 |
Yes | 143(99.3) |
No | 1(0.7) |
Most recent Pap smear | 137 |
Within last 12 months | 49(35.8) |
Between 1–2 years ago | 37(27.0) |
Between 2–5 years ago | 29(21.2) |
>5 years ago | 22(16.1) |
The total numbers reflect the number of respondents who answered the question regarding each variable. Not all respondents answered each question. Percentages may not total up to 100 due to rounding errors.
Prostate Cancer
Table 8 displays the frequency distribution of prostate cancer-related knowledge and attitudes. The majority of respondents believed that the risk of prostate cancer increased with older age (79%), high fat diets (61.6%), and smoking (56.9%),. A minority believed that having prostate cancer would adversely affect their marriages in general (41.9%) or affect their sexual relationships (45.5%).
Table 8.
Variables | N (%) |
---|---|
Old age increases prostate cancer risk | 121 |
Agree | 87 (79.0) |
Disagree | 17 (14.5) |
Don’t know | 17 (14.5) |
Diet high in fat increases risk of prostate cancer | 117 |
Agree | 72 (61.6) |
Disagree | 25 (21.4) |
Don’t know | 20 (17.1) |
Smoking increases risk of prostate cancer | 117 |
Agree | 66 (56.9) |
Disagree | 32 (27.6) |
Don’t know | 19 (15.5) |
Having a blood relative with prostate cancer increases the risk of prostate cancer | 117 |
Agree | 55 (47.0) |
Disagree | 40 (34.2) |
Don’t know | 22 (18.8) |
Having multiple sex partners increases risk of prostate cancer | 117 |
Agree | 28 (24.0) |
Disagree | 60 (51.3) |
Don’t know | 29 (24.8) |
How much would prostate cancer affect marriage | 111 |
A lot | 24 (20.5) |
Somewhat | 25 (21.4) |
Very little | 26 (22.2) |
Don’t know | 36 (30.8) |
How much would prostate cancer affect sexual relationship | 109 |
A lot | 29 (24.8) |
Somewhat | 23(19.7) |
Very little | 17(14.5) |
Don’t know | 40(34.2) |
The total numbers reflect the number of respondents who answered the question regarding each variable. Not all respondents answered each question. Percentages may not total up to 100 due to rounding errors.
Knowledge about PSA and self reported use of screening appears in Table 9. Of particular note, only 43.1% of the respondents had heard of PSA. Moreover, only 38.9% of respondents reported ever having a PSA and 20.3% had received the test within the prior year. Of those who had heard of the PSA, the percentages were approximately 88% and 52%, respectively. Of those respondents who had a PSA, 52.3% reported receiving the test within the last year. Most said that their doctor recommended the test or they made a joint decision regarding ordering the test. The large majority (92.7%) received the exam as part of a routine check up. In the bivariate analysis, none of the demographic or access variables were associated with receipt of a PSA within the past year. Individuals with a high school education or more (p<0.05) and those who had an ambulatory care visit within the past year (p<0.01) were more likely than others to report ever having a PSA. On the other hand, respondents living in the south (p<0.05) were less likely to report ever having the test.
Table 9.
Variables | N(%) | Total | |
---|---|---|---|
Have heard of prostate-specific antigen (PSA) | Yes | 50 (43.1) | 106 |
No | 56 (56.9) | ||
Ever had PSA | Yes | 44 (41.5) | 106 |
No | 62 (59.5) | ||
Had PSA within last 12 months | Yes | 23 (21.7) | 106 |
No | 83 (78.3) | ||
PSA can detect prostate cancer* | Agree | 35 (87.5) | 40 |
Disagree | 1 (2.5) | ||
Don’t know | 4 (10.0) | ||
PSA is accurate in finding prostate cancer* | Very accurate | 11 (27.5) | 40 |
Somewhat accurate | 23 (57.5) | ||
Don’t know | 6 (15.0) | ||
Concerned that PSA would find cancer* | Agree | 25 (53.2) | 47 |
Disagree | 18 (38.2) | ||
Don’t know | 4 (8.5) | ||
Difficult to take time to get PSA* | Agree | 38 (82.6) | 46 |
Disagree | 4 (8.7) | ||
Don’t know | 4 (8.7) | ||
Need more information on what, where and how to get PSA* | Agree | 28 (59.6) | 47 |
Disagree | 15 (31.9) | ||
Don’t know | 4(8.5) | ||
Transportation is not a problem to get PSA* | Agree | 19 (38.3) | 45 |
Disagree | 26 (55.4) | ||
No | 62 (59.5) | ||
Ever had PSA* | Yes | 44 (88.0) | 50 |
No | 6 (12.0) | ||
Most recent PSA* | Within last 12 months | 23 (52.3) | 44 |
1–2 years ago | 13 (29.5) | ||
2–5 years ago | 5 (11.4) | ||
>5 years ago | 3 (6.8) | ||
Who decided you should have PSA?* | Decided my own | 10 (23.8) | 42 |
Doctor ordered | 21 (50.0) | ||
Both Doctor and I agreed | 10 (23.8) | ||
Other | 1 (2.4) | ||
Why did you have PSA?* | Routine check-up | 38 (92.7) | 41 |
Medical problem | 3 (7.3) |
Percentages may not total up to 100 due to rounding errors
Asked of respondents who had heard of a PSA
Colorectal, Lung, and Nasopharyngeal Cancer
Knowledge, attitudes and behaviors related to colorectal, lung and nasopharyngeal cancer appear in Table10. The majority of respondents believed that low fiber diets (57.3%), high fat diets (62.1%) and smoking (52.5%) increased risk for colorectal cancer. Approximately one third of respondents reported ever having a colonoscopy. In the bivariate analysis, having health insurance (p<0.05), and having an ambulatory visit within the past year were associated with ever having a colonoscopy. Respondent living in the south were less likely than other to report ever having the test.
Table 10.
Variables | N(%) | Total | |
---|---|---|---|
COLON CANCER | |||
Diet low in fiber, fruits and vegetables | Disagree | 54 (20.8) | 260 |
increases risk of colorectal cancer | Agree | 149 (57.3) | |
Don’t know | 57 (21.9) | ||
Diet high in fat | Disagree | 35 (13.7) | 256 |
increases risk of colorectal cancer | Agree | 159 (62.1) | |
Don’t know | 62 (24.2) | ||
Smoking | Disagree | 61 (23.6) | 259 |
increases risk of colorectal cancer | Agree | 136 (52.5) | |
Don’t know | 62 (23.9) | ||
Having a blood relative who has had colorectal cancer | Disagree | 65 (25.1) | 259 |
increases risk of colorectal cancer | Agree | 120 (46.3) | |
Don’t Know | 74 (28.6) | ||
Ever had fecal occult blood test? | Yes | 97 (38.3) | 254 |
No | 75 (29.6) | ||
Don’t know | 81 (32) | ||
Ever had sigmoidoscopy | Yes | 38 (15.5) | 245 |
No | 207 (84.5) | ||
Ever had colonoscopy | Yes | 83 (33.1) | 251 |
No | 168 (66.9) | ||
LUNG CANCER | |||
Diet low in fruits and vegetable | Disagree | 113 (43.6) | 259 |
increases risk of lung cancer | Agree | 79 (30.5) | |
Don’t know | 67 (25.9) | ||
Being exposed to radiation | Disagree | 32 (12.4) | 258 |
increases risk of lung cancer | Agree | 175 (67.8) | |
Don’t know | 51 (19.8) | ||
Smoking cigarettes, pipes or cigars | Disagree | 14 (5.4) | 259 |
increases risk of lung cancer | Agree | 222 (85.7) | |
Don’t know | 23 (8.9) | ||
Inhaling someone else’s cigarette smoke | Disagree | 17 (6.6) | 258 |
increases risk of lung cancer | Agree | 215 (83.3) | |
Don’t know | 26 (10.1) | ||
Having diseases of the lung such as tuberculosis or | Disagree | 28 (10.9) | 258 |
bronchitis increases risk of lung cancer | Agree | 162 (62.8) | |
Don’t know | 68 (26.4) | ||
Pollution in the air | Disagree | 14 (5.4) | 258 |
increases risk of lung cancer | Agree | 201 (77.9) | |
Don’t know | 43 (16.7) | ||
NASOPHARYNGEAL CANCER | |||
Excessive drinking of alcohol beverages | Disagree | 53 (20.3) | 261 |
increases the risk of cancer of the oral cavity | Agree | 141 (54.0) | |
Don’t know | 67 (25.7) | ||
Chewing betel nut | Disagree | 65 (25.0) | 260 |
increases the risk of cancer of the oral cavity | Agree | 142 (54.6) | |
Don’t know | 53 (20.4) | ||
Smoking cigarettes, pipes or cigars | Disagree | 23 (8.8) | 261 |
increases the risk of cancer of the oral cavity | Agree | 201 (77.0) | |
Don’t know | 37 (14.2) | ||
Use of chewing tobacco | Disagree | 24 (9.2) | 261 |
increases the risk of cancer of the oral cavity | Agree | 199 (76.2) | |
Don’t know | 38 (14.6) |
The total numbers reflect the number of respondents who answered the question regarding each variable. Not all respondents answered each question. Percentages may not total up to 100 due to rounding errors.
The majority of participants knew that radiation exposure (67.8%), smoking (85.7%), and second hand smoke (83.3%) increased risk for lung cancer. Likewise, the majority believed that heavy alcohol intake (54%), chewing betel nut (54.6%), smoking (77%), and chewing tobacco (76.2%) increased risk of nasopharyngeal cancer.
DISCUSSION
This study provides the most comprehensive evaluation of cancer-related knowledge, attitudes, and behaviors among Chamorros ever published. The majority of respondents agreed with the medically recognized risk factors such as family history for breast cancer, sexually related activities for cervical cancer, dietary factors for colorectal cancer, smoking for lung cancer and chewing betel nut, a common practice in Guam, for nasopharyngeal cancer. However, the finding that less than half of the men had heard of the PSA test for prostate cancer was troublesome. Few Chamorros reported that ancient spirits, traditionally believed to be responsible for some illnesses on Guam, caused cancer. While approximately one third of participants had visited a traditional healer, very few would seek their care for cancer.
According to our results, Chamorros in our sample are being screened fairly well for breast and cervical cancer but less well for prostate and colorectal cancer. We did not determine the reasons for these findings; however, it is likely that the existence of clear guidelines for breast and cervical cancer screening and an active screening program for these cancers are at least partially responsible. Screening guidelines for prostate and colorectal cancer are less clear and no active screening programs exist on the island for these cancers. Unfortunately there are no effective screening tests for lung or nasopharyngeal cancer.
The US Preventive Services Task Force (USPSTF) recommends screening for breast cancer with mammography every 1–2 years for women aged 40 and older (14). Approximately 83% of Chamorro women in this study reported screening mammograms within this time frame. As such, they are meeting the Healthy People 2010 objectives of having 70% of women over the age of 40 years receive screening mammograms within the prior two years (15). Since we studied only women over the age of 50 years, it is possible that the proportion of women in the 40–50 year age group would have lower screening rates. However, for the older women, these findings are very encouraging. Our respondents reported higher rates than participants in a study in southern California, the only other published study regarding breast cancer screening specifically in Chamorro women (16). That study found that 25% Chamorro women over 40 years of age had a screening mammogram within the past year. Approximately 63% of women 50 years of age and older reported having mammography within the past two years (personal communication). At the national level, analysis of 2000 National Health Interview Survey revealed that approximately 70% of women over the age of 40 years and 73% of women over the age of 50 years reported having a mammogram within the past two years (17).
For cervical cancer, the USPSTF recommends beginning screening with Pap smears within 3 years of onset of sexual activity or age 21 (whichever comes first) and screening at least every 3 years thereafter until at least age 65 (14). National goals for cervical cancer screening include 97% of women ever having a Pap smear and 90% having one within the past three years (15). All but one woman in this study reported ever having a Pap smear, 62.8% within 2 years, and 84% within the past five years (because of the way the question was asked, we do not have data regarding Pap smears within the past three years). To our knowledge, there are no other published results on Pap smear use among Chamorro women. At the national level, 82.4% of women over the age of 25 years report having a Pap smear within three years; however, only approximately 70% of women over the age of 50 years (the age group of our sample) had the test within that time frame (17).
Screening guidelines for prostate cancer are less clear. The USPSTF concludes that the evidence is insufficient to recommend for or against routine screening for prostate cancer using PSA testing or digital rectal examination (DRE) (14). The American Cancer Society (18) believes that health care professionals should offer the PSA blood test and DRE yearly, beginning at age 50, to men who have at least a 10-year life expectancy. Because of the uncertainty regarding screening, the Healthy People 2010 report did not set specific goals for prostate cancer screening rates (15). Only 38.9% of respondents reported ever having a PSA and 20.3% had received the test within the prior year. Of those who had heard of the PSA, the percentages were much higher (81% and 55%, respectively). In the only other published study of PSA use among Chamorros, Wu and colleagues (19) found that 72.1% reported ever having a PSA and 41.9% had the test within the prior year in a convenience sample of men in San Diego. At the national level, 41% of men over the age of 50 years reported having a PSA test within the past year (17).
The USPSTF strongly recommends screening for colorectal cancer with fecal occult blood testing, sigmoidoscopy, and/or colonoscopy but find insufficient evidence to make recommendations about which screening strategy is best (14). The American Cancer Society (18) recommends one of five screening options beginning at age 50 for men and women: 1) FOBT or fecal immunochemical test (FIT) every year, or 2) flexible sigmoidoscopy every 5 years, or 3) an FOBT or FIT every year plus flexible sigmoidoscopy every 5 years, or 4) double-contrast barium enema every 5 years, or 5) colonoscopy every 10 years. National goals for colorectal screening by 2010 include having at least 50% of Americans over the age of 50 years having received fecal occult blood testing within two years and having a sigmoidoscopy ever (15). In our study, we asked only about ever having the screening tests. Overall, 38.3% of respondents reported ever having FOBT, 15.5% ever having sigmoidoscopy, and 33.1% ever having a colonoscopy. These figures fall well below the national goals. In the study of Chamorros in San Diego, investigators found that 40.3% of women and 24% of men reported ever having FOBT and that 42% of women and 33% of men reported ever having either sigmoidoscopy or colonoscopy (19,20). At the national level, 37.5% of women and 41% of men reported having either FOBT within the past year or colorectal endoscopy (15).
A number of factors were associated with increased cancer screening rates. For example, respondents who had a regular source of care were more likely to receive up to date mammography screening. Likewise, those who had visited their doctor within the past year were more likely to be screened for breast, cervical, prostate, and colorectal cancer. In addition, residents living in the north and central parts of the island were more likely to report screening. Efforts to encourage Chamorros to have a regular health care provider and visit her/him regularly could increase screening rates. Establishing cancer screening services at the public health clinic in the south or providing screening services in a mobile van in that area could also improve cancer control on Guam.
Because there are no effective screening tests for lung or nasopharyngeal cancer (14), primary prevention has been the main focus of efforts to control them. The most important risk factor for both of these cancers is tobacco use (21). Moreover, there is good evidence that smoking cessation decreases rates of these cancers. For example, compared with persistent smokers, a 30% to 50% reduction in lung cancer mortality risk has been noted after 10 years of cessation (23). In our study, it was encouraging to note that the majority of respondents knew that smoking was a risk factor for these cancers (85.7% for lung cancer and 77.0% for nasopharyngeal cancer). On Guam, the Department of Mental Health and Substance Abuse has an active tobacco control program. Key activities include technical assistance in the development of tobacco control-related policy and legislation, education and communications campaigns, training of key community leaders and volunteers on the harmful effects of tobacco use, and provision of cessation services to the Guam community.
Another risk factor for oral cancer on Guam deserves comment, chewing betel nut. Betel nut, or Areca nut, is the seed of the Betel Palm. Betel nuts are chewed for their effects as a mildly euphoric stimulant. On Guam, Betel nut (called Pugua'in the native Chamorro language) is used as a social pastime and can be found in many large gatherings. Betel nut chewing is an independent risk factor for oral cancer (24). In our study, only 54.6% of respondent knew that the chewing betel nut increased the risk of oral cancer. This finding points out the need for educational efforts that address the danger of this habit.
The study had several limitations. First of all, the sample was not selected randomly; therefore, the results may not be generalizable to all Chamorros on Guam. Likewise, we could not determine if the associations between demographic and access variables and use of cancer screening tests were independent associations because of the relatively small sample size. Finally, data came from self-reports and were subject to recall and desirability response bias. Because of the tendency for subjects to answer questions the way they think the interviewer would prefer (desirability response bias), they may have over-estimated the frequency of cancer screening test use (25–27).
In conclusion, our results suggest that screening for prostate and colorectal cancer is lagging behind screening for breast and cervical cancer for Chamorros on Guam. Culturally appropriate educational programs, encouraging regular visits to a health care provider, and outreach to those less likely to receive screening, such as residents of the southern part of Guam, could improve screening rates. The Pacific Islander Cancer Control Network has contributed to improved cancer education by developing and distributing brochures in English and Chamorro regarding cancer screening. However, cancer control requires more than screening. The paucity of health care professionals trained in chemotherapy use, palliative care, and other treatment of identified cancers limits care that can be provided (5). The expense of off island cancer care can be a barrier, particularly for low-income residents. Therefore, a comprehensive cancer prevention and control program on Guam is needed. Our report provides important information about Chamorro’s perspectives and screening behaviors that can help to guide such cancer control programs.
Acknowledgments
Sources of Support: Supported by grants from the National Cancer Institute (U01 CA 86073) and (P30 CA 62203). The contents of the manuscript are solely the responsibility of the authors and do not necessarily represent the views of the funding agency.
Footnotes
Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
REFERENCES
- 1.US Cancer Statistics Working Group. Atlanta: US Department of Health and Human Services, Centers for Disease Control and Prevention and National Cancer Institute; United States Cancer Statistics 2002: Incidence and Mortality. 2005
- 2.Pike MC, Kolonel LN, Henderson BE, Wilkens LR, Hankin JH, Feigelson HS, et al. Breast cancer in a multiethnic cohort in Hawaii and Los Angeles: risk factor-adjusted incidence in Japanese equals and in Hawaiians exceeds that in whites. Cancer Epidemiol Biomarkers Prev. 2002:795–800. [PubMed] [Google Scholar]
- 3.U.S. Census Bureau. [[cited 2007 jan 19]];Washington, DC: Department of Commerce, Economics and Statistics Administration; 2000 Census of Population and Housing. Social, economic, and housing characteristics. Guam. 2003 (PHC-4: Social, Economic, and Housing Characteristics—Island Areas: Guam) Available at URL: http://www.census.gov/prod/cen2000/phc-4-guam.pdf.
- 4.McMakin PD. The surhanos: traditional curers on the island of Guam. Micronesica: J University Guam. 1978;14:13–67. [Google Scholar]
- 5.Torsch VL, Ma GX. Cross-cultural comparison of health perceptions, concerns, and coping strategies among Asian and Pacific Islander elders. Qual Health Res. 2000;10:471–489. doi: 10.1177/104973200129118589. [DOI] [PubMed] [Google Scholar]
- 6.Chien-WEn T, Omphrony G, Cruz C, Naval CL, Haddock RL. Cancer in the Territory of Guam. Pac Health Dialog. 2004;11:57–63. [PubMed] [Google Scholar]
- 7.Haddock RL, Naval CL. Cancer on Guam: a report on the incidence of cancer and cancer deaths on the island of Guam, USA. Guam Cancer Registry; 2003. [Google Scholar]
- 8.Day LA. Designing and conducting health surveys. San Francisco: Jossey-Bass Publishers; 1989. [Google Scholar]
- 9.Hubbell FA, Luce PH, Afeaki WP, Cruz LA, Mummert A, McMullin JM, et al. Legacy of the Pacific Islander Cancer Control Network. Cancer. 2006;107(S):2091–2098. doi: 10.1002/cncr.22154. [DOI] [PubMed] [Google Scholar]
- 10.U.S. Dept. of Health and Human Services, National Center for Health Statistics. National Health Interview Survey, 2003 [Computer file]. Hyattsville, MD: U.S. Dept. of Health and Human Services, National Center for Health Statistics [producer], 1999n Arbor, MI: Inter-university Consortium for Political and Social Research [distributor]. 2001. (ICPSR No. 4222-v1) Available from: http://www.icpsr.umich.edu/cocoon/ICPSR/STUDY/04222.xml.
- 11.U.S. Dept. of Health and Human Services, National Center for Health Statistics. National Health Interview Survey, 1987: Cancer Control Study [Computer file]. Washington, DC: U.S. Dept. of Commerce, Bureau of the Census, and Hyattsville, MD: U.S. Dept. of Health and Human Services, National Center for Health Statistics [producers], 1989. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 1990. (ISPSR No. 9343) Available from: http://webapp.icpsr.umich.edu/cocoon/ICPSR-STUDY/09343.xml.
- 12.Beatty P, Herrmann D. A framework for evaluating “Don’t Know” responses in surveys; Proceedings of the Section on Survey Research Methods; Alexandria VA. American Statistical Association; 1995. pp. 1005–1010. [Google Scholar]
- 13.Marin G, Sabogal F, Marin BV, Otero-Saboal R, Perez-Stable EJ. Development of a short acculturation scale for Hispanics. Hisp J Behav Sci. 1987;9:183–205. [Google Scholar]
- 14.Rockville, MD: Agency for Healthcare Research and Quality; Guide to Clinical Preventive Services, 2005: Recommendations of the U.S. Preventive Services Task Force. 2005 June; (AHRQ Publication No. 05-0570) Available at URL: http://www.ahrq.gov/clinic/pocketgd05.
- 15.U.S. Department of Health and Human Services. [[cited 2007 jan 19]];Washington, DC: U.S. Government Printing Office; Healthy People 2010. With Understanding and Improving Health and Objectives for Improving Health. (2nd ed.). 2000 November;2 vols. Available at URL: http://www.healthypeople.gov/Document/tableofcontents.htm#tracking.
- 16.Tanjasiri SP, Sablan-Santos L. Breast cancer screening among Chamorro women in Southern California. J Womens Health Gend Based Med. 2001;5:479–485. doi: 10.1089/152460901300233957. [DOI] [PubMed] [Google Scholar]
- 17.Swan J, Breen N, Coates RJ, Rimer BK, Lee NC. Progress in cancer screening practices in the United States: results from the 2000 National Health Interview Survey. Cancer. 2003;97:1528–1540. doi: 10.1002/cncr.11208. [DOI] [PubMed] [Google Scholar]
- 18.American Cancer Society. Cancer Facts and Figures 2006. Atlanta: American Cancer Society; 2006. [Google Scholar]
- 19.Wu PL, Sadler GR, Nguyen V, Shi M, Cruz LAC, Blas FG, et al. Cancer risk factor assessment among Chamorro men in San Diego. J Cancer Educ. 2004;19:111–116. doi: 10.1207/s15430154jce1902_12. [DOI] [PubMed] [Google Scholar]
- 20.Nguyen V, Sadler R, Shi M, Gilpin EA, Cruz LA, Blas LA, et al. Cancer risk factor assessment among Chamorro women. J Cancer Educ. 2003;18:100–105. doi: 10.1207/S15430154JCE1802_13. [DOI] [PubMed] [Google Scholar]
- 21.Suarez L, Goldman DA, Weiss NS. Validity of Pap smear and mammogram self-reports in a low-income Hispanic population. Am J Prev Med. 1995;11:94–98. [PubMed] [Google Scholar]
- 22.Washington, DC: US Department of Health, Education, and Welfare; Smoking and Health: Report of the Advisory Committee to the Surgeon General of the Public Health Service. 1965 PHS Publ No 1103.
- 23.Cinciripini PM, Hecht SS, Henningfield JE, Manley MW, Kramer BS. Tobacco addiction: implications for treatment and cancer prevention. J Natl Cancer Inst. 1997;89(24):1852–1867. doi: 10.1093/jnci/89.24.1852. [DOI] [PubMed] [Google Scholar]
- 24.Warnakulasuriya S, Trivedy C, Peters TJ. Areca nut use: an independent risk factor for oral cancer. BMJ. 2002;324:799–800. doi: 10.1136/bmj.324.7341.799. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25.Zapka JG, Bigelow C, Hurley T, Ford LD, Egelhofer J, Cloud WM, Sachsse E. Mammography use among sociodemographically diverse women: the accuracy of self-report. Am J Public Health. 1996;8:1016–1021. doi: 10.2105/ajph.86.7.1016. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 26.Volk RJ, Cass AR. The accuracy of primary care patients’ self-reports of prostate-specific antigen testing. Am J Prev Med. 2002;22:56–58. doi: 10.1016/s0749-3797(01)00397-x. [DOI] [PubMed] [Google Scholar]
- 27.Jordan TR, Price JH, King KA, Masyk T, Bedell AW. The validity of male patients’ self-reports regarding prostate cancer screening. Prev Med. 1999;28:297–303. doi: 10.1006/pmed.1998.0430. [DOI] [PubMed] [Google Scholar]