Factors associated with breast cancer occurrence before the age of 40 in Yaoundé

Background: In Cameroon, one third of breast cancers concern women less than 40 of age and young age appeared to be an independent predictor of adverse outcome. This study aimed to determine factors associated with the development of breast cancer before the age of 40 in Yaoundé.Methods: A case-control study was conducted for 7 months, from November 1st, 2016 to May 31st, 2017 at the General Hospital and the gyneco-obstetric and Paediatric Hospital of Yaoundé. Study compared the socio-demographic, clinical and lifestyle data of 50 women less than 40 of age with breast cancer (cases) with those of 200 women below 40 of age without breast cancer (controls). Descriptive statistics, bivariate and multivariate logistic regressions were performed to assess the socio-demographic, clinical and lifestyle data. Data were computed using the SPSS version 23.0 software. The significance threshold value was set at 0.05.Results: After multivariate analysis, the factors independently associated with the occurrence of breast cancer before the age of 40 were: age ≥ 30 (aOR = 2.05); family history of breast cancer (aOR = 8.65); parity ≥ 1 (aOR = 2.46); breastfeeding (aOR = 3.39); waist circumference ≥ 88 centimeters (cm) (aOR = 4.38); breast density ≥ 90 (aOR = 2.89); physical activity ≤ 3 hours/week (aOR = 4.78). Conclusions: Breast cancer in women under 40 is associated with family history, reproductive life and women's lifestyles. Breastfeeding more than 12 months, having a balanced diet, supplementary screening tests in women with dense breasts and practicing physical activity; would be effective ways to prevent it in young women.