Abstract
Objective: Identify factors associated with knowledge of breast cancer and estimation of risk.
Methods: Telephone survey of 412 women aged 40 and over, living in Montreal and selected by random digit dialing.
Results: The majority of the respondents had recently been exposed to some information on breast cancer, but only a third quoted the average lifetime probability estimate of about 1 in 10. Older individuals systematically considered themselves at low risk (odds ratio (OR) of perceiving risk as lower than average for women aged 50 or over versus under 50: 2.6, 95% confidence interval: (1.5,4.6)). In addition, both a firstdegree family history of breast cancer (OR: 5.3 (1.7,17.0)) and a recent mammogram (OR: 3.0 (1.4,6.2)) were strongly associated with a woman’s probability of perceiving herself at high risk.
Conclusions: Information campaigns should emphasize the frequency of breast cancer in different age groups and the strength of the established associations with specific risk factors. Better knowledge of risk could promote sustained participation in breast screening programs.
Résumé
Objectif: Identifier les facteurs associés à la connaissance du cancer du sein et à la perception du risque de cette maladie.
Méthode: Entrevue téléphonique auprès de 412 femmes âgées de 40 ans ou plus, résidant à Montréal et sélectionnées de façon aléatoire.
Résultats: La majorité des répondantes avaient été exposées récemment à de l’information concernant le cancer du sein, mais seulement le tiers d’entre elles connaissaient la probabilité moyenne de cette maladie au cours de la vie, environ 1 sur 10. Les femmes plus âgées se considéraient systématiquement à faible risque (rapport des cotes (OR) de se percevoir à faible risque pour celles de 50 ans ou plus versus celles de moins de 50 ans: 2,6, intervalle de confiance à 95 %: (1,5, 4,6)). De plus, une histoire de cancer du sein chez une parente au premier degré (OR: 5,3 (1,7, 17,0)) et une mammographie récente (OR: 3,0 (1,4, 6,2)) étaient fortement associées à la probabilité de se considérer à risque élevé.
Conclusions: Les campagnes d’information devraient faire connaître la fréquence du cancer du sein dans différents groupes d’âge et la force des associations démontrées avec des facteurs de risque spécifiques. Une meilleure connaissance du risque est susceptible de stimuler la participation soutenue au dépistage.
References
- 1.Becker MH (Ed.). The health belief model and personal health behavior. Health Educ Monogr 1974;2:324–473.
- 2.Janz NK, Becker MH. The health belief model: A decade later. Health Educ Q. 1984;11:1–47. doi: 10.1177/109019818401100101. [DOI] [PubMed] [Google Scholar]
- 3.Evans DGR, Burnell LD, Hopwood P, Howell A. Perception of risk in women with a family history of breast cancer. Br J Cancer 1993;67:612- 14. [DOI] [PMC free article] [PubMed]
- 4.Claus EB, Risch N, Thompson WD. Genetic analysis of breast cancer in the Cancer and Steroid Hormone Study. Am J Hum Genet. 1991;48:232–42. [PMC free article] [PubMed] [Google Scholar]
- 5.Lerman C, Lustbader E, Rimer B, et al. Effects of individualized breast cancer risk counseling: A randomized trial. J Natl Cancer Inst. 1995;87:286–92. doi: 10.1093/jnci/87.4.286. [DOI] [PubMed] [Google Scholar]
- 6.Gail MH, Brinton LA, Byar DP, et al. Projecting individualized probabilities of developing breast cancer for white females who are being examined annually. J Natl Cancer Inst. 1989;81:1879–86. doi: 10.1093/jnci/81.24.1879. [DOI] [PubMed] [Google Scholar]
- 7.Black WC, Nease RF, Tosteson ANA. Perceptions of breast cancer risk and screening effectiveness in women younger than 50 years of age. J Natl Cancer Inst. 1995;87:720–31. doi: 10.1093/jnci/87.10.720. [DOI] [PubMed] [Google Scholar]
- 8.Dubin N, Pasternack BS. Risk assessment for case-control subgroups by polychotomous logistic regression. Am J Epidemiol. 1986;123:1101–17. doi: 10.1093/oxfordjournals.aje.a114338. [DOI] [PubMed] [Google Scholar]
- 9.Fischhoff B, Bostrom A, Quadrel MJ. Risk perception and communication. Annu Rev Public Health. 1993;14:183–203. doi: 10.1146/annurev.pu.14.050193.001151. [DOI] [PubMed] [Google Scholar]
- 10.Bar-Hillel M, Fischhoff B. When do base rates affect predictions? J Personality Soc Psychol. 1981;41:671–80. doi: 10.1037/0022-3514.41.4.671. [DOI] [Google Scholar]
- 11.Kash KM, Holland JC, Halper MS, Miller DG. Psychological distress and surveillance behaviours of women with a family history of breast cancer. J Natl Cancer Inst. 1992;84:24–30. doi: 10.1093/jnci/84.1.24. [DOI] [PubMed] [Google Scholar]
- 12.Lerman C, Daly M, Sands C, et al. Mammography adherence and psychological distress among women at risk for breast cancer. J Natl Cancer Inst. 1993;85:1074–80. doi: 10.1093/jnci/85.13.1074. [DOI] [PubMed] [Google Scholar]
- 13.Santé Québec; Bellerose C, Lavallée C, Chénard L, Levasseur M s l d de. Et la santé, ça va en 1992–1993? Rapport de l’Enquête sociale et de santé 1992–1993, Volume 1. Ministère de la santé et des services sociaux, Gouvernement du Québec. 1995. [Google Scholar]
- 14.Vogel VG, Graves DS, Vernon SW, et al. Mammographic screening of women with increased risk of breast cancer. Cancer. 1990;66:1613–20. doi: 10.1002/1097-0142(19901001)66:7<1613::AID-CNCR2820660728>3.0.CO;2-E. [DOI] [PubMed] [Google Scholar]
- 15.Kaplan KM, Weinberg GB, Small A, Herndon JL. Breast cancer screening among relatives of women with breast cancer. Am J Public Health. 1991;81:1174–79. doi: 10.2105/AJPH.81.9.1174. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Hailey BJ. Family history of breast cancer and screening behaviour: An inverted U-shaped curve? Medical Hypotheses. 1991;36:397–403. doi: 10.1016/0306-9877(91)90019-U. [DOI] [PubMed] [Google Scholar]
- 17.Stefanek ME, Wilcox P. First degree relatives of breast cancer patients: Screening practices and provision of risk information. Cancer Detection Prev. 1991;15:379–84. [PubMed] [Google Scholar]
- 18.Mah Z, Bryant H. Age as a factor in breast cancer knowledge, attitudes and screening behaviour. CMAJ. 1992;146:2167–74. [PMC free article] [PubMed] [Google Scholar]
- 19.Breslow R, Kessler L. Knowledge of breast cancer risk, by age. J Natl Cancer Inst 1995;87:1109.
- 20.Bondy ML, Vogel VG, Halabi S, Lustbader ED. Identification of women at increased risk for breast cancer in a population-based screening program. Cancer Epidemiol Biomarkers & Prev. 1992;1:143–47. [PubMed] [Google Scholar]
- 21.Bondy ML, Lustbader ED, Halabi S, et al. Validation of a breast cancer risk assessment model in women with a positive family history. J Natl Cancer Inst. 1994;86:620–25. doi: 10.1093/jnci/86.8.620. [DOI] [PubMed] [Google Scholar]
- 22.Spiegelman D, Colditz GA, Hunter D, Hertmark E. Validation of the Gail et al model for projecting individual breast cancer risk. J Natl Cancer Inst. 1994;86:600–7. doi: 10.1093/jnci/86.8.600. [DOI] [PubMed] [Google Scholar]