A non-invasive urinary test for telomerase reverse transcriptase (TERT) promoter mutations may identify recurrent urothelial bladder cancer (UBC) earlier than standard cytology and cystoscopy, a new study finds.
TERT often is reactivated in UBC by promoter mutations. In the British Journal of Cancer, Alain Ruffion, MD, PhD, of the University Hospital of Lyon in France, and colleagues reported that the urinary test for TERT promoter mutations displayed 80.5% sensitivity and 89.8% specificity for UBC. Urine cytology showed just 33.6% sensitivity overall and had an especially low 5.5% sensitivity for low grade pTa non-muscle invasive disease (NMIBC).
For the study, the team compared TERT mutation, cystoscopy, and cytology results from 348 patients who had transurethral resection of bladder tumor (TURBT) with 167 control patients with benign bladder conditions, other cancers, or no disease, over a median 11 months of follow-up at a single center.
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A positive TERT test following the first TURBT usually was associated with residual carcinoma in situ. Conversely, the test did not overreact to bladder inflammation or urinary tract infection.
A positive TERT test result after TURBT also was associated with a significant 5.34 times higher risk of NMIBC recurrence (excluding carcinoma in situ), according to results from univariate analysis. When the investigators evaluated the TERT test in a subset of patients with negative cystoscopy, the test came back positive in recurrent cases. The team suggested that such TERT testing might identify patients who would benefit from hexaminolevulinate fluorescence cystoscopy.
“The standard cytology test needs a doctor to look down a microscope to read the results, but the TERT test is read by a machine which is simpler, more accurate and available to use straightaway,” Dr Ruffion stated in a release issued by Cancer Research UK. “While the TERT test costs slightly more than standard cytology, it is likely to become cheaper over time.”
The team recommended that future studies assess the negative predictive ability of TERT promoter mutation testing, such as in cystoscopy cases showing inflammatory lesions or post-Bacillus Calmette-Guerin scarring. Also, the test’s positive predictive value should be further evaluated in cases of negative cystoscopy and cytology.
References
1. Descotes F, Kara N, Decaussin-Petrucci M, et al. Non-invasive prediction of recurrence in bladder cancer by detecting somatic TERT promoter mutations in urine. Br J Cancer 2017; 1–5; doi: 10.1038/bjc.2017.210
2. Simple test predicts return of bladder cancer. Cancer Research UK; July 7, 2017 [press release]
