Genomic determinants of early recurrences in low-stage low-grade endometrioid endometrial carcinoma.

Low-stage, low-grade endometrioid endometrial carcinoma (EEC), the most common histologic type of endometrial cancer, typically has a favorable prognosis. A subset of these cancers, however, display an aggressive clinical course with early recurrences, including distant relapses. All statistical tests were 2-sided. Using a combination of whole-exome and targeted capture sequencing of 65 FIGO stage IA/IB grade 1 EECs treated with surgery alone, we demonstrate that chromosome 1q gain (odds ratio (OR) 8.09, 95% confidence interval (CI) 1.59, 54.6, p = 0.02), PIK3CA mutation (OR 9.16, 95% CI 1.95, 61.8, p = 0.01) and DNA mismatch repair-deficient molecular subtype (OR 7.92, 95% CI 1.44, 87.6, p = 0.02) are independent predictors of early recurrences within 3 years in this patient population. Chromosome 1q gain was validated in an independent dataset of stage I grade 1 EECs subjected to whole-exome sequencing. Our findings expand on the repertoire of genomic parameters that should be considered in the evaluation of patients with low-stage low-grade EEC.