Body size, silhouette trajectory and the risk of breast cancer in a Moroccan case–control study

Background There is convincing evidence demonstrating that body size characteristics such as adiposity and height are associated with breast cancer in westernized countries. However, little is known about this relationship in North African countries currently undergoing nutritional transition and industrialization. The aim of this study was to explore associations between various body size characteristics, silhouette trajectories and the risk of breast cancer among Moroccan women. Methods In this case–control study conducted in the Fez region (2016–2017), detailed measures of body size were collected for 300 cases of breast cancer and 300 matched controls. Unconditional logistic regression was used to assess the association between body size and breast cancer risk adjusting for confounding factors. Results Higher waist circumference and hip circumference were positively associated with breast cancer risk in pre- (highest [T3] vs. lowest tertile [T1]: OR = 2.92, 95% confidence intervals [CI]: 1.33–6.42; OR = 3.00, 95% CI: 1.42–6.33, respectively) and post-menopausal women (T3 vs. T1: OR = 4.46, 95% CI: 1.86–10.66; OR = 4.08, 95% CI: 1.76–9.42, respectively). Body shape at younger ages (6–11 years) was inversely associated with the risk of breast cancer in premenopausal women (large vs. lean silhouette: OR = 0.31, 95% CI: 0.12–0.80). Women with the greatest increase in body shape trajectory had higher risk for both pre- and post-menopausal breast cancer (T3 vs. T1: OR = 2.74, 95% CI: 1.03–7.26; OR = 3.56, 95% CI: 1.34–9.44, respectively). Conclusion Our findings suggest that adiposity, body shape at younger ages, and silhouette trajectory may play a role in the development of pre- and post-menopausal breast cancer among Moroccan women. Larger-scale prospective studies are needed to confirm our findings and to explore these associations with breast cancer subtypes.