KRAS mutations in endometrial cancers: Possible prognostic and treatment implications

Patients with recurrent or metastatic endometrial cancer (EC) have poor prognoses with limited therapeutic options following immunotherapy or immunochemotherapy treatments. Inhibitors of KRAS mutations (KRAS-mut) have shown efficacy in early solid tumor studies, but data in EC are lacking. This study describes the frequency of KRAS-mut relative to other oncogenic alterations in EC to identify genomic characteristics of KRAS-mut tumors that could lead to novel therapeutic options.

A molecular database of 7870 ECs was queried for presence of oncogenic mutations and immunotherapy biomarkers. Comparisons were performed using Fisher-Exact/ChiSquare (p-values) and adjusted for multiple tests by Benjamini-Hochberg (q) and pairwise nonparametric analysis using Wilcoxon Method.

KRAS-mut is a relatively frequent genotype in EC, detected in 16% of cases. Codon 12 was most frequently mutated, with G12D (31%) and G12V (27%) the most common subtypes. Biomarkers of immunotherapy response co-occur with KRAS-mut. Microsatellite instability-high and tumor mutational burden-high status were observed in 34.1% and 36.5% in KRAS-mut compared to 19.8% and 16.9% in KRAS-WT, respectively (p < 0.05). PD-L1 >1% was detected in 8.4% vs 6.4% of KRAS-mut vs KRAS-WT (p < 0.05). BRCA1/2 mutations were detected with similar low frequency (5.9% vs 4.9%) among KRAS-mut and KRAS-WT ECs (p > 0.05). KRAS-mut was inversely associated with Her-2 overexpression (1.8% KRAS-mut vs 13% KRAS-WT. (p < 0.001).

KRAS-mut represents a genotypically distinct group of ECs. Overlap exists with genomic predictors (TMB-high, MSI-high) of immunotherapy response, suggesting a possible biomarker-driven combination option with immunotherapy. Clinical trials to evaluate these strategies should be developed.