The Impact of Sociodemographic, Reproductive and Lifestyle Factors on Breast Cancer Risk in Northwestern Algeria: A Case-Control StudyTop of Form

Background: Breast cancer represents the most prevalent malignancy among women worldwide and constitutes the leading cause of cancer-related mortality in the female population. The epidemiology of this pathology is shaped by a complex interplay of reproductive, genetic, dietary, and lifestyle determinants. Notwithstanding the considerable volume of global evidence, region-specific risk factor profiles remain insufficiently characterized across North African populations, thereby limiting the development of contextually appropriate prevention strategies.

Aims: The present study aimed to examine associations between breast cancer occurrence and a comprehensive set of reproductive, demographic, nutritional, and lifestyle factors among women residing in Western Algeria.

Patients and Methods: A total of 445 women from the Mascara region of Northwestern Algeria—comprising 163 confirmed breast cancer cases and 292 healthy controls—were enrolled in this hospital-based case-control study. Data were collected through structured face-to-face interviews employing a validated questionnaire addressing sociodemographic variables, reproductive and menstrual history, family history of breast cancer, lifestyle behaviors, and dietary habits. Body mass index (BMI) and waist-to-hip ratio (WHR) were derived from standardized anthropometric measurements. Crude odds ratios (OR) with 95% confidence intervals (CI) were estimated for each potential risk factor utilizing univariate logistic regression. Adjusted odds ratios (AOR) with corresponding 95% CIs were reported using a backward stepwise multivariate logistic regression model to identify independent predictors of breast cancer risk.

Results: In univariate analyses, BMI, WHR, marital status, place of residence, and educational attainment were not significantly associated with breast cancer risk. Higher household income was strongly associated with increased odds of disease, whereas retired employment status was associated with significantly lower odds compared to active employment (OR = 0.42; 95% CI: 0.19–0.92; p = 0.030). Short breastfeeding duration (≤6 months) was associated with markedly elevated risk (OR = 11.32; 95% CI: 4.80–26.68), and low daily water intake (≤1 L/day) was similarly associated with increased odds of breast cancer (OR = 1.63; 95% CI: 1.10–2.44). In multivariate analysis, independent predictors included younger age (AOR = 0.90; 95% CI: 0.87–0.93), monthly household income ≥50,000 DA (AOR = 2.08; 95% CI: 1.77–2.45), oral contraceptive use (AOR = 3.62; 95% CI: 1.62–8.09), breastfeeding ≤6 months (AOR = 1.50; 95% CI, 1.05–2.15), later menopause (AOR 1.05; 95% CI, 1.03–1.07), and older age at first pregnancy (AOR = 0.97; 95% CI, 0.94–0.99).

Conclusions: Breast cancer risk in this Northwestern Algerian population was independently associated with reproductive and socioeconomic determinants, particularly limited breastfeeding duration, oral contraceptive use, elevated household income, and later age at menopause. These findings contribute to the characterization of breast cancer risk profiles in North African women and provide an evidence base for the design of context-specific, population-targeted prevention and early detection strategies in this underrepresented region.