IKCS 2022: Delineating Clinical and Radiologic Features of Rare Kidney Cancer Genetic Syndromes

(UroToday.com) The tenth session of the 2022 International Kidney Cancer Symposium (IKCS): North America meeting focused on genetics of kidney cancer. In this context, Dr. Andrieu presented on clinical and radiologic features of rare kidney cancer genetic syndromes. By way of background, she noted that hereditary renal cell carcinoma (RCC) accounts for 5%-8% of all malignant renal tumors. There are 7 different syndromes that have been recognized by the NCCN. However, the clinical and radiologic features of at least four of these have been poorly characterized including Hereditary Papillary Renal Carcinoma (HPRC; MET gene), Birt-Hogg-Dube syndrome (BHDS; FLCN gene), BAP1 tumor predisposition syndrome (TPDS; BAP-1 gene), and Hereditary Paraganglioma/ Pheochromocytoma syndrome (PGL/PCC; SDHA-D genes).

Thus, these authors sought to investigate the prevalence of those syndromes, and prevalence, clinical features, and imaging features of RCC in these syndromes.

In the context of an institutional review board approved protocol, the authors performed germline analysis of 25,220 patients between 2015 and 2021 to assess more than 70 different cancer predisposing genes.

The authors identified patients with germline pathogenic or likely pathogenic mutations in MET, FLCN, BAP1 and SDHx. In addition to assessing the prevalence of germline mutations, the authors examined the clinical records to assess clinicopathologic characteristics. Additionally, radiographic features were determined based on CT/MRI/PET/CT at presentation which were reviewed independently by two radiologists.

The authors found that both clinical features and kidney cancer characteristics (eg. histology, size, etc) were not particularly enriched in this population, either when compared with other subsets of hereditary cancer or sporadic tumors.

The authors found that imaging features of hereditary RCC were similar to that of sporadic RCC.

She then provided some case examples including FLCN-mutated RCC, SDHB-deficient RCC, BAP1-mutated RCC.

The authors concluded that mutations associated with renal cell carcinoma syndromes are very infrequent, even among a cancer population. However, for those with these mutations, the prevalence of RCC is approximately 1 in 4. The imaging characteristics of hereditary RCC are similar to sporadic tumors.