Advancing the PD-L1 CPS test in metastatic TNBC: Insights from pathologists and findings from a nationwide survey

Fusco, N.; Ivanova, M.; Frascarelli, C.; Criscitiello, C.; Cerbelli, B.; Pignataro, M. G.; Pernazza, A.; Sajjadi, E.; Venetis, K.; Cursano, G.; Pagni, F.; Di Bella, C.; Accardo, M.; Amato, M.; Amico, P.; Bartoli, C.; Bogina, G.; Bortesi, L.; Boldorini, R.; Bruno, S.; Cabibi, D.; Caruana, P.; Dainese, E.; De Camilli, E.; Dell'Anna, V.; Duda, L.; Emmanuele, C.; Fanelli, G. N.; Fernandes, B.; Ferrara, G.; Gnetti, L.; Gurrera, A.; Leone, G.; Lucci, R.; Mancini, C.; Marangi, G.; Mastropasqua, M. G.; Nibid, L.; Orru, S.; Pastena, M.; Peresi, M.; Perracchio, L.; Santoro, A.; Vezzosi, V.; Zambelli, C.; Zuccala, V.; Rizzo, A.; Costarelli, L.; Pietribiasi, F.; Santinelli, A.; Scatena, C.; Curigliano, G.; Guerini-Rocco, E.; Martini, M.; Graziano, P.; Castellano, I.; D'Amati, G.

doi:10.1016/j.critrevonc.2023.104103

Pembrolizumab has received approval as a first-line treatment for unresectable/metastatic triple-negative breast cancer (mTNBC) with a PD-L1 combined positive score (CPS) of ≥ 10. However, assessing CPS in mTNBC poses challenges. Firstly, it represents a novel analysis for breast pathologists. Secondly, the heterogeneity of PD-L1 expression in mTNBC further complicates the assessment. Lastly, the lack of standardized assays and staining platforms adds to the complexity. In KEYNOTE trials, PD-L1 expression was evaluated using the IHC 22C3 pharmDx kit as a companion diagnostic test. However, both the 22C3 pharmDx and VENTANA PD-L1 (SP263) assays are validated for CPS assessment. Consequently, assay-platform choice, staining conditions, and scoring methods can significantly impact the testing outcomes. This consensus paper aims to discuss the intricacies of PD-L1 CPS testing in mTNBC and provide practical recommendations for pathologists. Additionally, we present findings from a nationwide Italian survey elucidating the state-of-the-art in PD-L1 CPS testing in mTNBC.

Advancing the PD-L1 CPS test in metastatic TNBC: Insights from pathologists and findings from a nationwide survey / Fusco, N.; Ivanova, M.; Frascarelli, C.; Criscitiello, C.; Cerbelli, B.; Pignataro, M. G.; Pernazza, A.; Sajjadi, E.; Venetis, K.; Cursano, G.; Pagni, F.; Di Bella, C.; Accardo, M.; Amato, M.; Amico, P.; Bartoli, C.; Bogina, G.; Bortesi, L.; Boldorini, R.; Bruno, S.; Cabibi, D.; Caruana, P.; Dainese, E.; De Camilli, E.; Dell'Anna, V.; Duda, L.; Emmanuele, C.; Fanelli, G. N.; Fernandes, B.; Ferrara, G.; Gnetti, L.; Gurrera, A.; Leone, G.; Lucci, R.; Mancini, C.; Marangi, G.; Mastropasqua, M. G.; Nibid, L.; Orru, S.; Pastena, M.; Peresi, M.; Perracchio, L.; Santoro, A.; Vezzosi, V.; Zambelli, C.; Zuccala, V.; Rizzo, A.; Costarelli, L.; Pietribiasi, F.; Santinelli, A.; Scatena, C.; Curigliano, G.; Guerini-Rocco, E.; Martini, M.; Graziano, P.; Castellano, I.; D'Amati, G.. - In: CRITICAL REVIEWS IN ONCOLOGY HEMATOLOGY. - ISSN 1040-8428. - 190:(2023). [10.1016/j.critrevonc.2023.104103]