Biological significance of TERT promoter mutation in papillary urothelial neoplasm of low malignant potential

Aims Mutations in FGFR 3 and the promoter region of the telomerase reverse transcriptase ( TERT ) gene have been found frequently in urothelial carcinoma of the urinary bladder. However, related data for papillary urothelial neoplasm of low malignant potential ( PUNLMP ) are limited. In this study, we investigated the mutation status of the TERT promoter, FGFR 3 and HRAS in low‐grade papillary urothelial neoplasms and evaluated their prognostic significance. Methods and results The cases included in this study comprised 21 inverted papillomas, 30 PUNLMP s and 34 low‐grade non‐invasive papillary urothelial carcinomas ( NIPUC s). TERT promoter mutations were observed in 10 (33%) PUNLMP s and 17 (50%) low‐grade NIPUC s, but not in any inverted papilloma. FGFR 3 mutations were observed more frequently in PUNLMP and low‐grade NIPUC than in inverted papillomas ( P =  0.009), whereas the opposite trend was noted for HRAS mutations ( P <  0.001). Regarding the clinical outcome, TERT promoter mutation was associated with a higher recurrence rate in PUNLMP ( P =  0.024) but not in low‐grade NIPUC ( P =  0.530). Notably, PUNLMP cases with TERT promoter mutations had a similar recurrence rate to that in low‐grade NIPUC cases ( P =  0.487). Conclusions Our results suggest that the status of the TERT promoter mutation may serve as a biomarker of prognostic stratification in patients with PUNLMP .