INVASIVE LOBULAR CARCINOMA OF THE BREAST: EPIDEMIOLOGICAL, CLINICAL, THERAPEUTIC AND EVOLUTIONARY PARTICULARITIES.

Introduction: Lobular carcinoma, though rare, is a form of breast cancer that requires special attention. This retrospective study analyzes 37 cases of invasive lobular carcinoma of the breast treated over a 7-year period at the Hassan II University Hospital in Fes. Materials and Methods: This retrospective study included 37 cases of ILC over 6 years at CHU Hassan II, Fes. All patients diagnosed with ILC during this period were included. Results: The median age of the patients was 55.27 years, with 21.6% on oral contraceptives and 67.7% postmenopausal. The average consultation delay was 5 months, and the main symptom was a breast nodule found in 81.1% of the patients. Ultrasound-mammography revealed lesions mainly classified as ACR5 in 62.2% of cases, and breast MRI was used in 10.8% of the patients. Histopathological analysis after core needle biopsy revealed ILC with lymph node involvement in 43.2%, capsular rupture in 18.9%, and vascular emboli in 21.6%. Most tumors were grade II according to the Scarff-Bloom-Richardson (SBR) system, with 94.6% of patients expressing hormone receptors and 29.7% weakly expressing HER2 receptors. The tumor was often classified as T2 (70.3%), N0 (59.5%), and metastatic M1 (16.2%). Regarding treatment, 35% of patients underwent initial surgery, and 35% received neoadjuvant chemotherapy, mainly with the AC60 + taxane protocol, which was well tolerated by most. Side effects included vomiting in 10 patients, hematological toxicity in 4, and taxane-related neuropathy in 2. Approximately 28.75% of patients received adjuvant chemotherapy, and 26.85% received radiotherapy. 16.2% of patients were followed by a genomic test Oncotype DX, and 94.6% received hormone therapy, mainly tamoxifen. The median follow-up was 40 months, with a 5-year overall survival rate of 91.89%. Conclusion: In conclusion, the diagnosis of invasive lobular carcinoma remains complex, but its treatment does not differ from that of invasive ductal carcinoma. [ABSTRACT FROM AUTHOR]