PD-L1 expression level in a large cohort from an Indian center.

Abstract

e14632 Background: PD-L1, or Programmed Death-Ligand 1, is a protein expressed on the surface of various cells, including tumor cells. PD-L1 is a key biomarker and therapeutic target for precision oncology. PD-L1 expression is a determinant of the efficacy of immune checkpoint inhibitors such as anti-PD-1 therapies and anti-PD-L1 therapies. In precision oncology, PD-L1 expression levels are used to tailor treatments, as high PD-L1 expression may favor monotherapy with immune checkpoint inhibitors, whereas low or negative PD-L1 expression might require combination therapies, such as immunotherapy with chemotherapy. The aim of this study was to determine the level of PDL1 expression in tumors in a tertiary hospital in India. Methods: Data were collected from 137 patients diagnosed with various types of tumors in the Medical Oncology Unit at Sarvodaya Hospital, Faridabad, India. Tumor Proportion Score (TPS) scoring for PDL 1 was performed by immunohistochemistry (IHC) using VENTANA (PS263) or DAKO (22C3) assays. Results: 137 patients were enrolled in the study with a median age of 65 years (range: 30-86), with 105 (76.6%) being male and 32 (23.4%) being female. Five patients (3.6%) were in the age group below 40 years, between 41-60 years of age, 38 (27.7%) patients, followed by 85 (62.0%) in 61-80 years of age, and 9 (6.6%) were > 80 years of age. The distribution of patients according to diagnosis showed that the major population was lung carcinoma in 61 patients (44.5%) (31 adenocarcinoma, 29 squamous cell carcinoma; NET 1).Cervical carcinoma was the second most common diagnosis (8 patients, 5.8%), followed by stomach cancer (7 patients, 5.1%), and other types of carcinoma constituted approximately 44.6% (61 patients). PDL-1 expression was categorized based on the score level. TPS < 1 (no expression) was observed in 52 patients (37.95%), 1-50% (low expression) in 59 patients (43.065%), and TPS > 50% (high expression) in 26 patients (18.978%) (Table -1). In lung carcinoma, PDL1 expression TPS 0% was observed in 27 patients (44.26%), TPS 1-20% was observed in 18 patients (29.50%), TPS 21-50% was observed in 3 patients (4.91%), and TPS > 50% was observed in 13 patients (21.3%). Conclusions: This study demonstrated the PDL1 expression levels in various types of cancer. High and low scores were observed in a large cohort. This predicts chances of a higher response with the addition of immunotherapy. These data necessitate greater accessibility to immunotherapy drugs. PDL1 expression in various groups. Variable TPS score <1% 1-50% >50% Gender Male 40(29.197)12(8.759) 43(31.386)16(11.678) 18(13.138)8(5.839) Female Site Lung 27(19.70)25(18.248) 21(15.328)38(27.737) 13(9.489)13(9.489) Others Total Number of patients (N=137) 52(37.95%) 59(43.06%) 26(18.97%)