Characterization and Impact of TERT Promoter Region Mutations on Clinical Outcome in Renal Cell Carcinoma

Abstract

BackgroundMutations in the promoter region of the TERT gene have been detected in a variety of cancers. These mutations can potentially lead to unlimited cell divisions and result in poor clinical prognosis. ObjectiveTo determine the role and relevance of TERT promoter region mutations in both clear cell (ccRCC) and non–clear cell (nccRCC) renal cell carcinoma using ultra-deep and whole-genome sequencing methods on primary tumor samples. Design, setting, and participantsDNA from 281 kidney tumors (147 ccRCC and 134 nccRCC) was sequenced between 2013 and 2015, and clinical outcomes for these patients from a single institution were retrospectively analyzed. Outcome measurements and statistical analysisDifferences in patient characteristics and mutational status were tested using Fisher's exact test for categorical variables and the Wilcoxon rank sum test for continuous variables. Survival times were estimated using the Kaplan-Meier method and differences were tested using the log-rank test. Results and limitationsTERT mutations occurred in 12.2% of ccRCC and 10.4% of nccRCC cases. In >80% of the cases, mutations were located at C228T and were found to co-occur only rarely with other relevant RCC driver genes. The median follow-up among survivors overall was 2.5 yr (range 0.1–18.3). TERT promoter mutations were significantly associated with cancer-specific survival in ccRCC (hazard ratio 2.68, 95% confidence interval 1.19–6.01; p=0.013). In nccRCC, TERT mutations were significantly associated with larger tumors and metastatic development. Assessment of further relevant clinical associations was precluded in the nccRCC group by the heterogeneous and small sample size. ConclusionsOur data suggests that TERT mutational status reflects a distinct pathogenesis with an aggressive disease course in RCC. Stratifying patients with this unique tumorigenesis that leads to poor clinical outcomes could be a putative target for novel therapeutics. Patient summaryWe show a previously unrecognized frequency of TERT promoter mutations in both clear cell and non–clear cell renal cell carcinoma. TERT promoter mutations were associated with some worse outcomes in patients with clear cell renal cell carcinoma.