Impact of stage migration on bladder cancer: A slow but steady improvement in the long term survival rates after radical cystectomy in the last 25 years

INTRODUCTION & OBJECTIVES: Bladder cancer (BCa) is a heterogeneous disease with up to 25% of incidental diagnoses reported to be found muscle invasive at first episode. Numerous markers and an increased awareness have been recorded in the recent years. We sought to evaluate if those considerat ions may determine a change in BCa clinical presentation at radical cystectomy (RC) over years in a single high volume tert iary referral center. MATERIAL & METHODS: The study relied on 2,003 consecutive BCa pat ients treated with RC and extended pelvic lymphadenectomy (PLND) at a single inst itution between January 1990 and December 2014. Pat ients were st ratified into tertiles according to the year of surgery (1990-2000 vs. 2001-2009 vs. 2010-2014). Anova and chi-square trend tests were used to report the clinical and pathological characterist ics of the cohort over t ime. Mult ivariable Cox regression analysis was used to test the relationship between year of surgery and recurrence, cancer specific mortality (CSM) and overall mortality (OM). RESULTS: When considering clinical characterist ics, patient age (66.7 vs. 66.5 vs. 67.6 years, p=0.1) and gender (81.9% vs. 82.7% vs. 85.4% male, p=0.2) resulted steady over the three tertiles. Conversely body mass index (BMI) (24.7 vs. 25.6 vs. 26.0, p<0.005) increased over the studied period. Considering pathological features, CIS detect ion (8.8% vs. 19.8% vs. 34.4%, p<0.001) showed an increasing rate, while pathological T3-4 stage (64.1% vs. 48.6% vs. 51.6%, p=0.005) expressed a decreasing t rend. The number of nodes removed increased during tertiles (16.8 vs. 22.7% vs. 26.78, p<0.001) resulting in an increased number of posit ive nodes over years (5.1 vs. 7.1 vs. 7.8, p<0.001). However, lymph node invasion (34.6% vs. 29.8% vs. 33.7%, p>0.1) remain stable across years in the overall populat ion. At multivariable Cox regression analyses, year of surgery represent a predictor of recurrence (HR: 0.97), CSM (HR: 0.97) and OM (HR: 0.98), with a slight but constant reduction in all survival outcomes (all p<0.04). CONCLUSIONS: A significant increase of BMI over years has been recorded in patients affected by BCa treated with RC. Considering pathological characteristics, higher rates of CIS but lower rates of pathological advanced disease were recorded in recent years, with a reduct ion in the prevalence of pT3/pT4 disease. These variat ions direct ly reflect the differences in terms of long term survival expectances recorded in our series across the last 25 years.