Shorter leukocyte telomere length is independently associated with poor survival in patients with bladder cancer

Background: Shorter telomere length (TL) has been reported to be associated with increased risk of early death in elder individuals. Telomere shortening has been also related to chromosomal instability, which may possibly contribute to the development of several types of digestive or urogenital system cancers and smoking-related tumors. Therefore, we investigated the impact of TL on bladder cancer survival. Methods: TL was measured in leukocyte DNA from whole peripheral blood using quantitative real-time PCR in 463 patients with bladder cancer from a total 726 cases who were followed for up to 18 years. Results: Patients with muscle-invasive tumor/any grade had shorter telomere than patients with non-muscle-invasive tumor/high-grade and with non-muscle-invasive tumor/non-high-grade (TL reference 0.7 ± 0.2; vs. respectively, 0.8 ± 0.2, P = 3.4 × 10^-2 and 0.8 ± 0.2, P = 3.6 × 10^-2). Moreover, patients in the lowest quartiles of TLwere associated with decreased survival after diagnosis (log-rank test, P = 3.9 × 10^-4). A Cox regression adjusted by age, cancer aggressiveness, Bacillus Calmette-Guérin, radical cystectomy, radiotherapy, and chemotherapy showed an independent effect of TL on bladder cancer survival (HR, 3.9; 95% confidence interval, 1.7-9.1; P = 1.2 × 10^-3). Conclusions: Our results suggest that leukocyte TL is only partly related to tumor aggressiveness and that shorter telomeres act as independent prognostic predictor of survival in patients with bladder cancer. TL information may allow to better select therapeutic approaches in patients with the same stage and grade. Impact: Blood leukocyte TL levels could provide an additional noninvasive prognostic marker to better predict survival and personalize therapies in patients with bladder cancer.