Interest of PD-L1 in the management of triple negative breast cancers in Ivorian patients

Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer that does not express hormonal receptors and Her2. Its prevalence is high and varies from 30 to 41% in the Ivory Coast. For decades, chemotherapy has remained the only systematic treatment choice; however, the current availability of programmed death-ligand 1 (PD-L1) immunohistochemistry provides benefits for immune checkpoint inhibitors. The purpose of the study aimed to determine the prevalence of PD-L1 and its relationship with specific prognostic features for better survival of TNBC patients in the Ivory Coast. A 10-month prospective study included 132 patients diagnosed with TNBC. The paraffin blocks were subjected to PD-L1 immunohistochemistry. The Chi-Square Test was used to evaluate the correlations between PD-L1 status and prognostic parameters. The mean age at diagnosis was 46.6 ± 12.9 years. 62.9% of the study population were premenopausal. The predominant histological type was invasive ductal carcinoma of no special type (95.5%) at the advanced stage of grade II (59.1%) and III (27.3%). There was an abundant inflammatory stroma (67.4%). 20.5% of TNBC patients were PD-L1 positive. PD-L1 status was significantly associated with the breast imaging-reporting and data system (BIRADS) scoring (p = 0.0362) and Nottingham grade (p = 0.0049). However, there was no association between PD-L1 expression and menopausal status (p = 0.1771), sex (p = 0.3030), inflammatory stroma (p = 0.0803), tumor necrosis (p = 0.0571), and histological type (p = 0.2037). 20.5% of TNBC patients expressed PD-L1. This study highlights a significant association between PDL-1 expression and the BIRADS scoring and the Nottingham grade. The present study could help to select patients who would be likely to benefit from anti-PD-L1 immunotherapy for better clinical outcomes in the Ivory Coast.