Investigation of the age trends in patients with breast cancer and different sizes of tumors in Breast Cancer Research Center of Isfahan University of Medical Sciences in 2001-2010

Abstract

Background:

Breast cancer is the most common cause of death in women in the age range of 35-55 years. Each year, one or two cases of breast cancer per 1000 women are diagnosed as new cases. Despite the serious prognosis and high rate of morbidity, mortality, and pathogenicity, in the case of early diagnoses, the prognosis will be better. The aim of this study was to investigate the age trends in breast cancer patients with different sizes of tumors in Breast Cancer Research Center of Isfahan University of Medical Sciences in 2001-2010.

Materials and Methods:

The information in radiotherapy and oncology of Isfahan University of Medical Sciences and Milad Hospital from 2001 to 2010 were coded and analyzed. Frequency of patients’ age groups, tumor sizes and the year of cancer diagnosis were calculated. Correlation test was used for data analysis in statistical analysis in social science (SPSS) software version 18.

Findings:

Among the 3722 patients with breast cancer, the highest relative frequency distribution, respectively was observed in the age of 40-49 years (34.4%), 50-59 years (26.6%), 30-39 years (17.7%), 60-69 years (13.2%), 20-29 years (2.5%), 70 years and older (5.2%) and less than 20 years. Relative frequency distribution of tumor sizes in a variety of 5 cm (T2) was with the frequency of 59.8%, and then 26% at 5 cm (T3), 10.5% at 2 cm (T1), 3.1% at T4 and 0.6 at In-situ, respectively.

Conclusion:

The investigation of age trends showed that diagnosis rate of breast cancer increased from 2001 to 2004. It reached its highest value in 2006 at the age range of 30-39 years. Then, the trend has been downward, and it has continued to decline until 2010, which could be the result of the equipping screening system and recording the malignant cases. 85.8% of the examined tumors in T2 and T3 group were visible and may be disturbing. Comparing the frequency distribution of the infected population showed that the highest incidence of breast cancer diagnosis were in the age range of 40-49 years. It seems that as long as the mass has not reached an obvious palpable state, it has not been diagnosed.

INTRODUCTION

Breast cancer is the most common cause of death in women in the age range of 35-55 years. Each year, one or two cases of breast cancer per 1000 women are diagnosed as new cases.[1] American Cancer Society statistics showed that in 2010, there were 1,592,560 new cases of cancer and 490,569 cases of death from cancer in the United States. Breast cancer with the incidence of 192,380 new cases in 2009 was the most common cancer in women (27%) and the main cause of cancer deaths among them.[2] In Iran, as well, cancer is one of the most important health and treatment problems and is the major cause of death in the country after road accidents and cardiovascular diseases.[3] The risk of developing breast cancer in women in their lifetime is 12.5% (one case out of eight cases), and the risk of death from breast cancer is 3.6% (one case out of 28 cases).[4] In Iran, breast cancer is highly prevalent. According to the latest report on the country, breast cancer has been the third most common cancer in a total of men and women.[5] The highest incidence of breast cancer was among the women between the ages of 40-49 years.[6] The report of the Cancer Registry Center of the Ministry of Health and Medical Education of Iran showed that breast cancer has been allocated the most new cases of cancer (24.41% of all cancers in women) among the Iranian women. The study of Majid et al., found that women in Sulaymaniyah of Iraq had the age of onset of breast cancer in the age group of 35-39 years and by increasing the age, the incidence of breast cancer has been decreased in patients with higher ages.[7] The obtained information of the Egypt and Jordan studies were the same as the study of Sulaymaniyah of Iraq.[8] The most incidence of cancer in western countries was in the age group of 70-74, age group of 45-49 years in Taiwan and 55-59 years in Iraqi Kurdistan.[7] Isfahan is located in the first ranking of cancer in the country, and the breast cancer among women has been assigned the first place to itself. Based on the statistics of 2004, about 10% of breast cancer cases in the country have been reported in Isfahan.[9] Nokiani et al., study during 2001-2004 on women in Kermanshah province showed that the mean patient age was between 46 years and 34% were less than 40 years. These values are disturbing compared to western countries, which only 6% of the patients were less than 40 years.[10] Age is the main risk-factor for most human malignancies including breast cancer. Breast cancer in young women (under 35 years) is a rare disease and only 2% of patients at the time of diagnosis were in this age group.[11] Almost 70% of women on admission are in advanced stages of the disease. In this situation, therapeutic agents cannot do so much for them.[12] The exact size of the tumor and its spread at diagnosis has a significant impact on the type of surgery and adjuvant therapy for these patients. In Iran, 72% of patients are diagnosed with the tumor size of more than two centimeters and 63% of them with lymph node involvement at diagnosis, which shows the high emergence of advanced cancer in Iranian women at the presentation.[6] This size is 1.8 cm in western countries.[13] There is often a close link between tumor size and the final result of the disease. Generally, patients with small tumors (diameter of two centimeters or less) have a better prognosis than patients with having larger tumors (especially more than 5 cm in diameter).[14] Breast tissue is dense in young people and with increasing the age; it is being gradually replaced by fatty tissue. Despite the poor prognosis, high mortality, and morbidity, in the case of early diagnoses, the prognosis will be better for patients.[15] The overall risk of cancer is higher in old age; because of the time, that the person has been exposed to carcinogens is more. By the way, the immune system is also decreased with increasing age and people are more at risk. In this study, the obtained information from radiotherapy and oncology departments of Isfahan University of Medical Sciences and the Milad Hospital were analyzed by using the correlation analysis (Spearman correlation coefficient) in order to obtain a realistic picture of the age trends in tumors with different sizes, provided services and future needs for screening, prevention and treatment services.

MATERIALS AND METHODS

This study was a cross-sectional descriptive analytic study. The trend of diagnosis and treatment of the cancer requires specialized medical facilities. Information was studied from the records of patients in radiotherapy and Oncology Departments of Isfahan University of Medical Sciences and the Ultra Specialized Milad Hospital in 2001 and 2010. The information was categorized and coded and then the selected codes were collected and analyzed. There were 3,722 cases and the recent data were more complete than the early years. Data on age, gender, tumor size and year of cancer diagnosis were extracted from the files. Clinical data and tumor size are presented as indicators for breast cancer. Thus, the studied groups were included: In-situ tumors equal or less than 2 cm (T1), equal or more than two or less than 5 cm (T2), more than 5 cm (T3) and finally, any tumor that had spread to the skin or chest wall directly (direction extension) (T4). The statistical indicators, relative abundance and Spearman correlation coefficient were used for data analysis in SPSS software version 18. P <0.05 was considered as statistically significant indicator of data.

FINDINGS

The age distribution of breast cancer during the studied years and based on the patient records in Table 1 showed that most of the patients who were diagnosed with breast cancer, respectively were in the age range of 40-49 years (with relative frequency 34.4%), 50-59 years (with relative frequency 26.6%), 30-39 years (with relative frequency 17.7%), 60-69 years (with relative frequency 13.2%), 20-29 years (with relative frequency 2.5%), 70 years and older and less than 20 years (with relative frequency 5.2%). Age trends of patients in groups of 10 years, based on the results in Table 1 and Figure 1 showed that breast cancer diagnosis’ frequencies were increased from 2001 to 2004. The highest value reached in 2006 at the age of 30-39, and then the trend has been downward and has continued to decline until 2010. The results of Table 2 and Figure 2 showed that the most distribution relative frequency of tumor sizes based on the age trend was 59.8% in T2 and thereafter, 26% in T3, 10.5% in T1, 3.1% in T4, and 0.6% In-situ and 0.6, respectively. The relative frequency distribution of studied tumors in T2 and T3 groups was 85.8%. The comparison of the frequency distribution of the studied population showed that the highest rate of breast cancer prognosis was in the age group of 40-49 years. Correlation analysis of the patient records showed that the correlation between age and year of diagnosis was not statistically significant. It was (P = 0.90) in patients with In-situ tumors, (P = 0.917) in patients with T1 tumor size, (P = 0.68) in patients with T3 tumor size and patients with T4 tumor size (P = 0.26), while the group of patients with T2 tumor size had a positive correlation (P = 0.032).

Table 1.

Frequency and relative Frequency of age distribution of patients by years of cancer diagnosis

Figure 1.

Age trends of breast cancer patients 2001-2010

Table 2.

Frequency and relative Frequency distribution of tumor sizes at age groups

Figure 2.

Age trends of breast cancer patients with different tumor sizes 2001-2010

DISCUSSION

The mean age of the patients in the study of Harirchi et al., in Tehran was mentioned as 48.8 years.[16] In the report of Mousavi et al., the age group of 40-49 years had the highest frequency among the patients.[6] In Ebrahimi et al., study, the age groups of patients with breast cancer have been lower than western countries.[17] Yavari et al., have reported 48.8 ± 9.8 years as the patients’ mean age.[18] The results of the study of Babazadeh et al., calculated the mean age of the patients as 48.79 ± 11.85 years.[8] The mean age of breast cancer in Tunisia has been reported as 51 years.[19] In addition, the mean age of 50 years has been reported in the Arabic region.[20] In Hong Kong, India and Malaysia in comparison with western countries, the age group for breast cancer has been reported less than a decade in western countries.[8] In addition, black women (under the age of 40 years) are afflicted with breast cancer a decade earlier.[20] The results of the present study in Isfahan showed that the most patients were diagnosed with breast cancer at the age range of 40-49 years (34.4%). The investigation of age trends in groups of ten years indicated that prognosis of breast cancer increased from 2001-2004. In 2006, in the age group of 30-39 years, it has reached the highest value and the trend has been downward and continued to decline until 2010. The results of Babazadeh et al., study in Isfahan showed that more than 92% of patients had tumor sizes equal or larger than T2.[8] In Harirchi et al., study, the frequency of T2 was reported 83% or higher.[16] Mousavi et al., in the investigation of published Persian literature has reported this amount as 72%.[6] In addition, in Tunisia among the 1408 samples of breast cancers, the followings were indicated: 12.2% T1, 49.9% T2, 8.2% T3 and 24.7% T4.[19] The results of the present study showed these frequencies: 59.8% T2, 26% T3, 10.5% T1, 3.1% T4 and 0.6% In-situ. The results indicated that as long as the mass is not palpable and obvious, it has not been diagnosed. However, the obtained data from the studied tumor sizes showed a better trend of diagnosis and recording of the data in recent years. However, the frequency of 85.8% from the examined tumors in T2 and T3 groups were well visible and perhaps disconcerting. Therefore, comparing the relative frequency distribution pattern of the observed population showed that the most frequent diagnosis of breast cancer was in the age group of 40-49 years. On the other hand, about 17.7% of the patients in the age range of 30-39 were diagnosed with breast cancer, which suggests that, in patients under 39 years of age, referred to a physician later. These results would suggest the awareness of at risk women community and screening them. Therefore, it would be better to perform screening the diagnosis of breast cancer under the age of 39 years.