Purpose: Germline pathogenic variants are estimated to affect 3-5% of renal cell carcinoma (RCC) patients. However, higher mutational prevalence in non-clear cell RCC (non-ccRCC) and advanced disease has been suggested.
Methods: To clarify the prevalence of pathogenic germline variants in metastatic RCC, we sequenced 29 cancer susceptibility genes in 294 unselected metastatic RCC cases plus 21 patients with clinical hereditary features. In 145 tumors, genes frequently mutated in RCC were sequenced and methylation was assessed in selected cases.
Results: Germline variants in RCC predisposition genes (FH, VHL) were detected in 1.4% of the unselected metastatic patients, with higher frequency in non-ccRCC versus ccRCC (6.4% and 0.4%; P = 0.0025) and in younger patients (P = 0.036). Among the 315 studied patients, 14% of non-type 1 papillary cases (4 of 28), all metastatic <1 year after diagnosis, carried a FH germline variant with loss of heterozygosity and tumor genome hypermethylation. Variants in other cancer-associated genes (e.g., MUTYH, BRCA2, CHEK2) occurred in 5.1% of the unselected series, with unclear significance for RCC.
Conclusion: Our findings confirm a high prevalence of pathogenic germline variants in RCC predisposition genes in metastatic non-ccRCC, and highlight that metastatic patients with papillary type 2 or unconventional histologies compatible with FH would benefit from genetic screening.