Epidemiological and molecular profile of breast cancer: a retrospective study in Casablanca, Morocco.

Introduction: breast cancer is a major public health concern in Morocco due to delayed diagnosis and treatment, largely due to its high incidence. It is the most prevalent cancer in women. This study aimed to report the epidemiological and the molecular profile of invasive breast carcinoma using surrogate immunohistochemical markers.

Methods: during 24 months from 1^st January 2020 to 31^st December 2021 at the Pathology Department of Ibn Rochd University Hospital of Casablanca, Morocco, we conducted a retrospective study comprised 1,558 breast cancer cases, including male patients. The generated data was analyzed using GraphPad Prism 8 software to define the epidemiological and molecular features of breast cancer.

Results: this epidemiological study reveals that the mean age of patients was 52 ± 12.27 years. The most common histological type is invasive breast carcinoma of no special type, which accounts for 90.5% (n=1,410) of cases. Regarding Ellis and Elston modified Scarff-Bloom-Richardson (SBR) grade, grade III was the most common, 52.2% (n=521), followed by grade II, 44% (n=438), and grade I, 3.8% (n=38), as assessed by the SBR grade. The molecular classification results indicate that luminal B was the most common subtype at 52.2% (n=441), followed by triple-negative at 19.6% (n=166), with HER2 phenotype representing 17.4% (n=147) and luminal A at 10.8% (n=91).

Conclusion: this study highlights that invasive breast carcinoma of no special type is the most common type, with grade III tumors being the most frequent. The majority of cases were luminal B, underscoring the need for targeted therapeutic strategies.