Urinary TERT promoter mutations as non-invasive biomarkers for the comprehensive detection of urothelial cancer
Dr Florence Le Calvez-Kelm is a senior scientist in the Genetic Cancer Susceptibility group at the International Agency for Research on Cancer (IARC), Lyon. She is leading the Agency-wide Genomics platform and coordinates collaborative genomic projects within IARC and outside. She is currently coordinating research projects that propose to investigate the potential of tumor-derived molecules in various body fluids as non-invasive biomarkers for early detection of cancer (pancreatic and urothelial cancers).
Background. Recurrent mutations in the promoter of the telomerase reverse transcriptase (TERT) gene (C228T and C250T) detected in tumours and cells shed into urine of urothelial cancer (UC) patients are putative biomarkers for UC detection and monitoring. However, the possibility of detecting these mutations in cell-free circulating DNA (cfDNA) in blood and urine, or DNA from urinary exfoliated cells (cellDNA) with a single-gene sensitive assay has never been tested in a case-control setting.
Methods. We developed a single-plex assay (UroMuTERT) for the detection of low-abundance TERT promoter mutations. We tested 93 primary and recurrent UC cases and 94 controls in France (blood, urine samples and tumours for the cases), and 50 primary UC cases and 50 controls in Portugal (urinary exfoliated cell samples). We compared our assay with urine cytology.
Findings. In the French series, C228T or C250T were detected in urinary cfDNA or cellDNA in 81 cases (87·1%; 95% CI 78·6-93·2), and five controls (Specificity 94·7%; 95%CI 88·0-98·3), with 98·6% (95% CI 92·5-99·96) concordance in matched tumours. Detection rate in plasma cfDNA among cases was 7·1%. The UroMuTERT sensitivity was (i) highest for urinary cfDNA and cellDNA combined, (ii) consistent across primary and recurrent cases, tumour stages and grades, (iii) higher for low-risk non-muscle invasive UC (86·1%) than urine cytology (23·0%) (P<0·0001) and (iv) 93·9% when combined with cytology. In the Portuguese series – the sensitivity and specificity for detection of UC with urinary cellDNA was 68·0% (95% CI 53·3-80·5) and 98·0% (95% CI 89·3-100·0).
Interpretation. TERT promoter mutations detected by the UroMuTERT assay in urinary DNA (cfDNA or cellDNA) show excellent sensitivity and specificity for the detection of UC, significantly outperforming that of urine cytology notably for detection of low-grade early stages UC
Perspectives. We are now exploring the possibility to detect TERT promoter mutations in pre-diagnostic urine samples as it could be enormous potential as a non-invasive tool for early detection and potentially cost-effective screening of high-risk individuals. I will report preliminary findings of our case-control study nested within a longitudinal prospective population-based cohort of 50,045 Iranian individuals, where we assessed the detectability of these mutations in urine samples collected at enrolment.
Senior scientist in the Genetic Cancer Susceptibility group
International Agency for Research on Cancer (IARC), Lyon
CRCN Genetic Epidemiology of Cancers Team, U900, INSERM-Institut Curie (Domain 3)
Domain 3 - U900 - CBIO - Bioinformatics, Biostatistics Epidemiology and Computational Systems