A hypothesis-generating analysis on the role of TERT promoter mutation in advanced urothelial carcinoma treated with immunotherapy

Background: The therapeutic scenario of urothelial carcinoma is constantly expanding with the widening of the knowledge on molecular characteristics, thus claiming for the need of prognostic and predictive factors to guide treatment strategy. TERT promoter mutation is one of the most frequent genomic alterations in urothelial car-cinoma and could present several implications, from diagnostic to prognostic or potentially even predictive. Methods: We performed a single-center retrospective analysis on patients with advanced urothelial carcinoma treated with an immune checkpoint inhibitor as second line of therapy to assess the status of the TERT promoter and the potential implication of its mutation on survival outcomes. Results: We analyzed tissue samples from 11 patients with a next-generation sequencing multi-gene panel. The most frequently altered genes were TP53 (54.5%, n = 6) and TERT promoter (36.3%, n = 4). Other mutations found were BRAF, SMAD4, PIK3CA / PDGRFA. The only type of detected TERT promoter mutation was the c 0.124 C > T (n = 4/4, 100%). Of the 4 TERT mutated patients, 2 presented a co-mutation of TP53. Patients with TERT promoter mutation treated with immunotherapy presented a low median overall survival (16.5 months) and progression-free survival (3.8 months). Conclusions: Our hypothesis-generating analysis suggests that the presence of TERT promoter mutation could have a negative prognostic value and should be further evaluated in wider cohorts.