[The first experience of PD-L1 testing of triple negative breast cancer with marker SP142 in Russia].

Aim Of Study: To evaluate the pecularities of PD-L1 expression in triple negative breast cancer (TNBC) in the Russian population.

Materials And Methods: For 7 months, within a scientific study of the Russian Society of Clinical Oncology (RUSSCO), we determined the PD-L1 status of 58 patients with TNBC. In each case, an immunohistochemical study was performed in a closed Ventana Bench Mark Ultra automatic stainer using a closed protocol with rabbit monoclonal antibodies Ventana PD-L1 SP142 and Opti View DAB IHC Detection Kit with Opti View Amplification Kit.

Results: Positive PD-L1 status in TNBC was detected in 37.93% of cases. Almost all tumors had an expression level of up to 10%. Only 5.17% of cases showed ligand expression on tumor cells.

Conclusions: According to the results of the first experience of testing PD-L1 in TNLM in Russia, it was possible to obtain data comparable to the same data of large international studies. RUSSCO's information and logistic support allows making this analysis available to all citizens of the country.