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

[BACKGROUND] 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.

[METHODS] 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.

[RESULTS] 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 ( = 0.0362) and Nottingham grade ( = 0.0049). However, there was no association between PD-L1 expression and menopausal status ( = 0.1771), sex ( = 0.3030), inflammatory stroma ( = 0.0803), tumor necrosis ( = 0.0571), and histological type ( = 0.2037).

[CONCLUSION] 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.