[Synchronous bilateral breast cancer: experiences in the Mohammed VI Cancer Treatment Center, CHU Ibn Rochd, Casablanca].

Synchronous bilateral breast cancers (SBBC) are characterized by extensive clinical and morphological heterogeneity, with an frequency between 1.5 and 3.2%. Women treated for unilateral breast cancer are at higher risk of developing contralateral breast cancer. Screening and advances in breast imaging have improved detection rates of SBBC. Our study aims to analyze the epidemiological, clinical, histological and therapeutic features of bilateral breast cancer. We conducted a cross-sectional study of patients with breast cancer treated at the Mohammed VI Center over a two year period. Statistical analysis of the results was performed using R. software. 31 patients had SBBC, representing 2.4% of breast cancer cases in our Center. The average age was 47.8 ± 8.4 years, 22.6% of patients used oral contraceptives. A family history of breast cancer was observed in 22.6% of cases. The most common histological type was invasive ductal carcinoma (58.1%), SBR grade II and III were common (38.7%). Hormone receptors were positive for progesterone (38.7%) and for estrogen (41.9%). HER2 was overexpressed in 20.0% of cases. 29.0% of patients received hormonal therapy and 3.2% targeted therapies. Our study showed that bilateral breast cancer represents a small percentage of all breast cancers but have specific clinical features that help to differentiate it from unilateral breast cancer.