Abstract 4283: Assessment of the tumor mutational burden in a large cohort of Chinese advanced pan-cancer patients

Abstract

Abstract Background: Immunotherapy have led to a paradigm shift in cancer treatment, while only a small subset of patients can benefit from the treatment. Recent studies have revealed that tumor mutational burden (TMB) is positively correlated with immunotherapy, however, by far, limited data are available for Chinese tumor patients. Methods: We retrospectively assessed the TMB value with a validated 381-cancer-gene panel across 7,822 patients with advanced cancers, including gastric cancer (n= 457), gallbladder cancer (n=608), colorectal cancer (n=785), breast cancer (n=263), Hepatocellular carcinoma (n=904) and lung cancer (n=2135), Renal cell carcinoma (n=346), Liver cancer (904), NSCLC (2135), Melanoma (110), Ovarian cancer (177), Pancreatic cancer (363), Gastric carcinoma (457), Urinary tract cancer (166) and others. Results: A highest 20% of TMB in each histology was selected as the cut-point. Based on our analysis, the highest and the lowest TMB level was observed in endometrial cancer and RCC, respectively. More specifically, the TMB cut-point was 10.5 for biliary tumor, 9.7 for breast cancer, 15.2 for endometrial cancer, 12.1 for CRC, 49.8 for endometrial cancer, 12.1 for oesophageal cancer, 11.1 for head and neck carcinoma, 7.3 for RCC, 10.1 for HCC, 14.5 for NSCLC, 8.9 for melanoma, 8.1 for ovarian cancer, 7.4 for pancreatic cancer, 11.3 for GC, and 20.1 for urinary tract cancer. Consistent results were observed when the median TMB was applied in the analysis. Conclusion: This is the first study focusing on the distribution of TMB value in a large cohort of Chinese cancer patients. The results showed the varying distributions of TMB across histology and suggested that a high TMB status may not assigned by one universal cut-point across different cancer types. Our findings have provide clues to guide the treatment strategy in clinical practice and shed lights on the future trial design. Citation Format: Ping Liu, Longgang Cui, Shangli Cai. Assessment of the tumor mutational burden in a large cohort of Chinese advanced pan-cancer patients [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4283.