Pathogenic germline mutation profile in Chinese lung cancers and related-driver mutation pattern.

Abstract

e13003 Background: Many cancers could be driven by germline mutation exampled as BRCA1/2 in breast or ovarian cancer. However, the candidate predisposition variants for Chinese lung cancer are largely unknown. Methods: We reviewed 1797 Chinese lung cancer patients with paired tumor-normal samples sequenced by a 1021 gene panel. The annotation of germline variants within 95 selected susceptible genes was based on ACMG 2015 version guideline. Results: The frequency of patients identified with pathogenic or likely pathogenic (P/LP) germline variants were 5.95% (107 in 1797), which elevated to 10.1% (9 in 89) in patients younger than 40. Totally, 112 mutations from 35 genes were screened out. Recurrent pathogenic germline genes were BRCA2 (n = 14), FANCA (n = 9), RAD51D (n = 7), MUTYH (n = 7), ATM (n = 7) and TP53 (n = 5). The average age at diagnosis was numerically 2 years earlier in patients with P/LP (mean, 58.2 vs. 60.0, p = 0.22) than other patients without significance, but different genes contribute to discordant effects. Significantly early onset age was found in germline BRCA1/ 2 mutation (median, 52.5 versus 60.0 yrs in patients without P/LP, p = 0.0080) while later onset age was associated with germline PMS2 mutation (median, 74 versus 60.0 yrs, p = 0.0214 ). In terms of clinical actionable somatic mutation, the frequency of KRAS (15/89, 16.85% versus 121/1429, 8.47%, p = 0.012) and c-MET (6/89, 6.74% versus 31/1429, 2.17%, p = 0.018) in germline mutant patients were significantly higher, while TP53 (41/89, 46.07% versus 847/1429, 59.27%, p = 0.019) was apparently less mutated in P/LP lung cancer. As for frequency of EGFR, ALK, ROS-1, RET and BRAF, mutation frequency were not significantly different in lung cancer with germline mutation. Conclusions: Our study delineated the pathogenic germline mutation landscape in Chinese lung cancers for the first time. Predisposition genes demonstrated clinical actionable roles in onset age and therapeutic interventions. Further follow up may clarify the contribution of germline mutation to somatic mutation driven targeted therapy response and prognosis.