Type 1, Type 2 Papillary Renal Cell Carcinomas Biologically Distinct
Specific alterations seen in type 1 and type 2 carcinomas; type 2 consists of at least 3 subtypes.
(HealthDay News) -- Type 1 and type 2 papillary renal-cell carcinomas are characterized by specific genetic alterations, according to a study published online in the New England Journal of Medicine.
W. Marston Linehan, MD, from the National Cancer Institute in Bethesda, Md., and colleagues performed comprehensive molecular characterization of 161 primary papillary renal-cell carcinomas. Whole-exome sequencing, copy-number analysis, messenger RNA and microRNA sequencing, DNA-methylation analysis, and proteomic analysis were conducted.
The researchers found that types 1 and 2 papillary renal-cell carcinomas were characterized by specific genetic alternations, with type 2 subclassified into 3 individual subtypes based on molecular differences that correlated with patient survival. MET alterations were seen in association with type 1 tumors. CDKN2A silencing, SETD2 mutations, TFE3 fusions, and increased expression of the NRF2-antioxidant response element pathway characterized type 2 tumors. A distinct subtype of type 2 papillary renal-cell carcinomas that was characterized by poor survival and mutation of the fumarate hydratase gene exhibited a CpG island methylator phenotype.
"Type 1 and type 2 papillary renal-cell carcinomas were shown to be clinically and biologically distinct," the authors write. "Type 2 papillary renal-cell carcinoma consisted of at least 3 subtypes based on molecular and phenotypic features."