Abstracts
Résumé
Le cancer du sein est une préoccupation majeure de santé publique. En 2001, plus d’un million de nouveaux cas et 372 969 décès attribuables au cancer du sein ont été enregistrés dans le monde. Il existe suffisamment de preuves permettant d’affirmer que la susceptibilité génétique, l’exposition à des facteurs environnementaux et à des facteurs liés au style de vie jouent un rôle important dans l’étiologie de cette maladie. Cet article présente une synthèse entre facteurs de risque et fondements biologiques de la maladie à partir de données tirées de récentes publications spécialisées. L’âge avancé, l’âge précoce lors des premières menstruations, la ménopause tardive, la grande taille à l’âge adulte, les maladies bénignes du sein, la densité élevée du tissu mammaire en mammographie, l’obésité après la ménopause, l’histoire familiale de cancer du sein, les radiations ionisantes, certaines mutations génétiques, la consommation importante d’alcool, l’utilisation des contraceptifs oraux et du traitement hormonal substitutif sont associés à un risque accru de cancer du sein. La maternité précoce, la multiparité, l’activité physique régulière, l’allaitement et le maintien de l’équilibre énergétique réduisent ce risque. Une constante identification des facteurs de risque, sur lesquels il est possible d’agir, devrait faciliter la mise en oeuvre de stratégies efficaces de prévention.
Summary
Because of its increasing incidence, breast cancer is a significant burden for women worldwide. In industrialized countries, breast cancer is the second-leading cause of cancer-related deaths among women, and it is estimated that 1 in every 8 women will develop the disease during her lifetime. Sufficient evidence indicates that a number of genetic, environmental and lifestyle risk exposures during life may play important roles in the etiology of this disease. The purpose of this paper is to review some etiologic factors and underlying mechanisms in relation to breast cancer risk. Based on the published literature, there is sufficient evidence that some established factors are associated with breast cancer risk. Age, early age at menarche, late menopause, height, post-menopausal obesity, family history of breast cancer, ionizing radiation, oral contraceptives, hormonal replacement therapy, mammographic density, some gene mutations and clinical conditions, such as benign breast disease, are associated with an increased risk of breast cancer. The risk decreases with early childbearing, high parity and physical activity, and breastfeeding. Alcohol increases the risk, while caloric restriction may confer protection from breast cancer. Epidemiological evidence for other nutritional factors is insufficient. These results suggest that breast cancer is a multifactorial disease where genetic susceptibility, environment, nutrition and other lifestyle risk factors interact. Better identification of modifiable risk factors and risk reduction of breast cancer may allow implementation of useful strategies for prevention.
Appendices
Références
- 1. International Agency for Research on Cancer. Overweight and lack of exercise linked to increased cancer risk. In : IARC Handbooks of cancer prevention, vol. 6. Weight control and physical activity. Lyon : IARC Press, 2002.
- 2. Kaur JS. Migration patterns and breast carcinoma. Cancer 2000 ; 88 : 1203-6.
- 3. Initiative canadienne sur le cancer du sein. Rapport sommaire : examen des facteurs de risque de cancer du sein liés au style de vie et à la l’environnement. http://www.hc-sc.gc.ca/pphb-dgspsp/publicat/
- 4. World Cancer Research Fund/American Institute for Cancer Research. Expert report. Food, nutrition and the prevention of cancer : a global perspective. Washington, DC : American Institute for Cancer Research, 1997.
- 5. Key TJ, Verkasalo PK, Banks E. Epidemiology of breast cancer. Lancet Oncol 2001 ; 2 : 133-40.
- 6. Collaborative group on hormonal factors in breast cancer. Breast cancer and hormonal replacement therapy : collaborative reanalysis of individual data from 51 epidemiological studies of 52,705 women with breast cancer and 108,411 women without breast cancer. Lancet 1997 ; 350 : 1047-59.
- 7. Collaborative group on hormonal factors in breast cancer. Breast cancer and hormonal contraceptives : collaborative reanalysis of individual data on 53,297 women with breast cancer and 100,239 women without breast cancer from 54 epidemiological studies. Lancet 1996 ; 347 : 1713-27.
- 8. Writing group for the Women’s Health Initiative investigators. Risks and benefits of estrogen plus progestin in healthy postmenopausal women. Principal results from the Women’s Health Initiative randomized controlled trial. JAMA 2002 ; 288 : 321-33.
- 9. Million Women Study Collaborators. Breast cancer and hormone : replacement therapy in the Million Women study. Lancet 2003 ; 362 : 419-27.
- 10. Layde PM, Webster LA, Baughman AL, et al. The independent associations of parity, age at first full term pregnancy, and duration of breastfeeding with the risk of breast cancer. Cancer and steroid hormone study group. J Clin Epidemiol 1989 ; 42 : 963-73.
- 11. Hinkula M, Pukkala E, Kyyronen P, Kauppila A. Grand multiparity and the risk of breast cancer : population-based study in Finland. Cancer Causes Control 2001 ; 12 : 491-500.
- 12. Russo J, Hu YF, Yang X, Russo IH. Developmental, cellular, and molecular basis of human breast cancer. J Natl Cancer Inst Monogr 2000 ; 17-37.
- 13. Collaborative group on hormonal factors in breast cancer. Breast cancer and breastfeeding : collaborative reanalysis of individual data from 47 epidemiological studies in 30 countries, including 50,302 women with breast cancer and 96,973 women without the disease. Lancet 2002 ; 360 : 187-95.
- 14. Key TJ, Pike MC. The role of oestrogens and progestagens in the epidemiology and prevention of breast cancer. Eur J Cancer Clin Oncol 1988 ; 24 : 29-43.
- 15. Petrakis NL, Wrensch MR, Ernster VL, et al. Influence of pregnancy and lactation on serum and breast fluid estrogen levels : implications for breast cancer risk. Int J Cancer 1987 ; 40 : 587-91.
- 16. Kennedy KI. Effects of breastfeeding on women’s health. Int J Gynaecol Obstet 1994 ; 47 : S11-20.
- 17. Pharoah PD, Day NE, Duffy S, et al. Family history and the risk of breast cancer : a systematic review and meta-analysis. Int J Cancer 1997 ; 71 : 800-9.
- 18. Ford D, Easton DF, Stratton M, et al. Genetic heterogeneity and penetrance analysis of the BRCA1 and BRCA2 genes in breast cancer families. The Breast Cancer Linkage Consortium. Am J Hum Genet 1998 ; 62 : 676-89.
- 19. Wolpert N, Warner E, Seminsky MF, et al. Prevalence of BRCA1 and BRCA2 mutations in male breast cancer patients in Canada. Clin Breast Cancer 2000 ; 1 : 57-63.
- 20. Boice JD. Cancer following irradiation in childhood and adolescence. Med Pediatr Oncol 1996 ; 1 (suppl) : 29-34.
- 21. Little MP, Muirhead CR, Haylock RG, Thomas JM. Relative risks of radiation-associated cancer : comparison of second cancer in therapeutically irradiated populations with the Japanese atomic bomb survivors. Radiat Environ Biophys 1999 ; 38 : 267-83.
- 22. Kelsey JL, Bernstein L. Epidemiology and prevention of breast cancer. Annu Rev PublHealth 1996 ; 17 : 47-67.
- 23. Boyd NF, Lockwood GA, Byng JW, et al. Mammographic densities and breast cancer risk. Cancer Epidemiol Biomarkers Prev 1998 ; 7 : 1133-44.
- 24. Wenten M, Gilliland FD, Baumgartner K, Samet JM. Associations of weight, weight change, and body mass with breast cancer risk in Hispanic and non-Hispanic white women. AnnEpidemiol 2002 ; 12 : 435-44.
- 25. Kirschner MA, Samojlik E, Drejka M, et al. Androgen-estrogen metabolism in women with upper body versus lower body obesity. J Clin Endocrinol Metab 1990 ; 70 : 473-9.
- 26. Friedenreich CM, Courneya KS, Bryant HE. Influence of physical activity in different age and life periods on the risk of breast cancer. Epidemiology 2001 ; 12 : 604-12.
- 27. Johnson KC, Hu J, Mao Y. Passive and active smoking and breast cancer risk in Canada, 1994-97. The Canadian Cancer Registries Epidemiology Research Group. Cancer CausesControl 2000 ; 11 : 211-21.
- 28. MacMahon B, Andersen AP, Brown J, et al. Urine estrogen profiles in European countries with high or low breast cancer rates. Eur J Cancer 1980 ; 16 : 1627-32.
- 29. de Waard F. Risk factors for breast cancer at various ages. Eur J Cancer Prev 1998 ; 7 (suppl 1) : S13-5.
- 30. Collaborative group on hormonal factors in breast cancer. Alcohol, tobacco and breast cancer : collaborative reanalysis of individual data from 64 epidemiological studies, including 64,534 women with breast cancer and 131,348 women without breast cancer. Br J Cancer 2002 ; 87 : 1234-45.
- 31. Feigelson HS, Calle EE, Robertson AS, et al. Alcohol consumption increases the risk of fatal breast cancer (United States). Cancer Causes Control 2001 ; 12 : 895-902.
- 32. Yu H. Alcohol consumption and breast cancer risk. JAMA 1998 ; 280 : 1138-9.
- 33. Key TJ, Schatzkin A, Willett WC, Allen NE. Diet, nutrition and the prevention of cancer. Publ Health Nutr 2004 ; 7 : 187-200.
- 34. Michels KB, Ekbom A. Caloric restriction and incidence of breast cancer. JAMA 2004 ; 291 : 1226-309.