Germline mutations in hereditary renal cell carcinoma (RCC) genes among 32,240 patients with all cancer types.

Abstract

4559 Background: Germline pathogenic variants (PVs) in VHL, FH, BAP1 and others cause hereditary syndromes with increased risk of renal cell carcinoma (RCC). Defining the clinical spectrum of these syndromes has been limited by ascertainment bias and their relative rarity. Using a large population of cancer patients who underwent germline and somatic tumor testing, we analyzed the landscape of germline PVs in RCC genes in individuals with all cancer types. Methods: We identified patients with germline PVs in RCC genes ( VHL, FH, SDHB, MET, FLCN, BAP1) in the MSK-IMPACT cohort, an institutional protocol of patients who had somatic and germline sequencing. The MITF E318K variant was analyzed separately given its uncertain role in RCC risk. Objectives were to determine whether patients met clinical criteria for their respective hereditary syndromes, analyze biallelic inactivation in all tumor types, and explore underrecognized cancer associations. Fisher test was used to compare frequency of variants to population. Results: Of 32,240 patients who consented to germline results, 55% were female; most common cancer types were breast (n=3600), pancreas (n=3554), prostate (n=3427), with 1166 (3.6%) with RCC. 110 (0.34%) had a germline variant in a RCC syndrome gene ( BAP1=26, SDHB=24, FH=24, FLCN=19, VHL=16, MET=1). Of 110 germline positive, 56% met clinical criteria for their hereditary syndrome, and 40% had RCC. For VHL, FH, SDHB and MET, a high proportion of patients met criteria for their hereditary syndromes, but this was much less for FLCN (Birt-Hogg-Dubé) and BAP1. Biallelic inactivation in the tumor, supporting causality, was very high except in FLCN. Possible novel cancer associations were liver cancer in BAP1 (n=5;19%) and colon cancer in FLCN (n=4;17%). Additionally, 114 patients had the MITF E318K variant; which was not enriched in RCC cases (only 1 RCC) compared to other cancers or population control (odds ratio 0.45; p-value = 0.16, 95% confidence interval: 0.1 -1.2). Conclusions: Germline analysis in a large pan-cancer cohort identifies a high prevalence of patients with hereditary RCC syndromes, variability in clinical phenotype and suggestion of novel cancer associations. The low number of MITF E318K variant carriers in RCC cases calls into question its role in RCC risk and warrants further study. [Table: see text]