CLINICOPATHOLOGICAL FEATURES OF BREAST CARCINOMA WITH DIFFERENT MOLECULAR SUBTYPES IN MOROCCAN WOMEN, DATA ABOUT 1040 CASES

Abstract

Background: Breast cancer is a major public health problem worldwide. It's the most common cause of death from cancer in women, it considers a heterogeneous disease, shows variable morphological and biological features, they have different clinical behavior, and prognoses, and respond to therapy differently despite similarities in histological types, grade, and stage. The classication aims for an accurate diagnosis and prediction of behavior, however, histological classication isn't enough in this era of personalized medicine, this results in « overtreatment » of many patients, so, molecular proling allows tumors to be dened by the expression pattern or genomic alteration of thousands of genes. A Methods: retrospective, descriptive and analytic study was performed among 1040 women with invasive breast carcinoma, which was diagnosed in the department of surgical pathology at University Hospital Center of Hassan 2 of Fez in Morocco, during a period ranging from 2012 to 2019. The prevalence of different molecular subtypes of breast carcinoma was estimated, in addition, clinicopathological features such as age, tumor size, tumor grade, lymph node involvement, hormonal receptors prole, and HER2 status have been compared. The mean age of diagnosis was Results: 49.5 years (DS12,5 years, 17-88 years), among these, 637 (55%) were under 50 years. NOS invasive breast carcinoma was the histological type the most common in 1030 (89%), with an SBR II in 60% of cases. The Mean tumor size was 2.8cm. Axillary lymph nodes (LN) were metastatic in 60% of cases. 76% of cases showed positive staining for estrogen receptors, 75,5% for progesterone receptors, and 18,5% for HER2/neu. Luminal A subtype was found in 22% of patients while Luminal B was present in 62,5% of patients, HER2 enriched in 5%, and triple-negative (TN) in 10,5 % of cases. There is signicant difference between the 4 subclasses by age (P=0.02), SBR grading (p<0,0001), tumor size (p=0,05), lymph node metastasis (0,0001). There are more young women in HER2 enriched and luminal B subtypes than in luminal A and TN subtypes, while the rate of older women is increased in luminal A subtypes. The proportion of patients with histological grade III in the TN subtype and HER2 subtype, is signicantly increased (P<0.0001) while grade I is signicantly increased in the luminal A subtype. LN metastasis in the luminal B and Her2 cancers are more signicant than in luminal A and TN. Disease-free survival (DFS) among older women above 50 years is signicantly greater among young women under 40 years ( p=0,021). Regarding SBR grading, and DFS, we found that survival was signicantly highest for patients with grade I, followed by those with grade II and then grade III (P<0.0001). According to molecular subtypes, we noted that DFS was signicantly highest for patients with luminal-A subtype, followed by those with luminal B subtype, then HER2 and TN cancers (P<0.0001). The Conclusion: present study shows the particularities of women breast carcinoma in our countryo, through our results, we found that BC is diagnosed at a younger age, a decade earlier than in developed countries, and we found a predominance of luminal B subtype in contrary with others studies suggesting that there are clinico-biological differences, as well as disparities in the expression proling in our population. This highlights the importance of early screening and the need to improve women's awareness of breast cancer in our region and additional research is needed to understand these results in hopes of adopting more effective therapies.