Pan-Cancer analysis of the mutation frequency of genes in DDR pathway in Chinese population.

Abstract

e15109 Background: The DNA damage repair (DDR) pathway is of vital importance to maintain human genomic stability. And the variation of DDR pathway related genes is closely related to tumorigenesis, tumor progression and therapeutic response. In order to comprehensively study the mutation status of DDR pathway related genes in human cancers, we evaluated the genomic features of Chinese pan-cancer patients and investigated the mutation frequency of genes in DDR pathway. Methods: A total of 5018 patients consisting of more than 22 cancer types were enrolled in this study. Utilizing target next-generation sequencing (NGS) platform, genomic profiling of 599 cancer-related genes was performed on tumor tissue or blood samples. And many DDR pathway related genes are included and detected mutations such as TP53, BRCA2, BRCA1, ATM, BLM, FANCA, POLE and so on. Results: We observed 91.23% (4578/5018) of cases harbored at least one alteration of the DDR pathway genes. The mutation frequency ranges from 71.88% to 100.00% among the 22 cancer types. Among them the DDR gene mutation frequency of lymphoma, esophagus and esophagogastric junction cancer and endometrial cancer are all 100%, and mutation frequency of bowel cancer, hepatobiliary cancer, melanoma, breast cancer, esophageal cancer, gastric cancer and central nervous system cancer are also more than 90% respectively. The highest mutation rate gene is a well-known tumor suppressor gene TP53, which mutated in 2650 patients and the mutation rate is 52.81%. And it primarily mutated in esophageal cancer, with a mutation rate of 81.43%. Besides the mutation rate of TP53 in gastric cancer, bowel cancer, breast cancer, ovarian cancer, pancreatic cancer, bladder cancer and hepatobiliary cancer are all more than 50%. Followed by is BRCA2 gene, which is also a tumor suppressor gene and the mutation rate is 16.04%. Next is ATM, BLM and FANCA, the mutation rate of which is 11.68%, 11.12% and 8.97% respectively. Conclusions: We find a unique genomic feature of DDR pathway in the comprehensively analysis of the mutation profile of the Chinese pan-cancer patients, which may provide potential therapeutic targets in the future.