EPIDEMIOLOGIE, FACTEURS DE RISQUE DU CANCER DU SEIN - ETUDE CAS-TEMOINS WILAYA DE TLEMCEN - 2011-2012

Abstract

Background Breast cancer is the leading cancer among women both in developed and developing countries. Its incidence is increasing in developing world is due to longer life expectancy, increasing urbanization and the adoption of western lifestyles. Several risk factors have been clearly identified, including family history, reproductive factors associated with prolonged exposure to endogenous estrogen, such as precocious puberty, a late menopause or late first pregnancy are among the most important risk factors. Women using oral contraceptives or hormone replacement therapy are at higher risk. Breastfeeding has a protective effect. In Algeria, the frequency of breast cancer is clearly increasing and the deaths attributed are also increasing and affects more young women. Our research was undertaken in order to check whether the breast cancer in the Tlemcen population was linked to a family history of breast cancer. Material and Methods This investigation allows us to establish the epidemiology of the disease and to evaluate the association with other risk factors. We conducted a case-control study within this population. 320 cases of incident breast cancer recruited at the University Hospital, EHS and the EPSP in the province of Tlemcen, and 640 controls recruited at the polyclinics among the wilaya, matched by age and place of residence of the cases. Results A significant positive association was detected between first-degree relatives and breast cancer Odd [Ratio (OR) = 4.98; Confidence Interval (CI) 95%: CI 95 %( 1.52-16.26)]. A positive association was detected between passive smoking and breast cancer [OR = 3.58; CI95 %( 1.94 - 6.11)]. In addition, a positive association was detected between the onset of menopause and breast cancer [OR = 2.84;CI95 % ( 1.11-7.21)]. Also, a positive association was found between breast cancer and the menstrual cycle more than 28 days [OR = 6.73; CI95 %( 3.50 -12.94). Women married or have been married seem to be protected against breast cancer compared to single women [OR = 0.21; CI 95% (0.09 - 0.47)]. However, there was no association between breast cancer and reproduction factors, the other socio-demographic and anthropometric factors. The survival rate at 24 months is estimated at 0.93 ± 0.01 with a mean of 32.75 ± 9.51 months followed. Conclusion The investigation and analysis relating to classical factors suggest some research questions that could improve in the future understanding of phenomena related to breast cancer genesis. Keywords: Breast cancer, Case-control, Risk factors, Conditional logistic regression