Can neoadjuvant gemcitabine plus carboplatin followed by immediate cystectomy improve survival in patients with cisplatin-ineligible muscle-invasive bladder cancer?

Abstract

e15565 Background: Standard neoadjuvant chemotherapy has not yet been established for patients with muscle-invasive bladder cancer (MIBC) who are ineligible for cisplatin based chemotherapy. In the present study, we conducted a propensity score analysis to elucidate the clinical significance of neoadjuvant gemcitabine and carboplatin chemotherapy (GCarbo) for cisplatin-ineligible patients with MIBC. Methods: The cohort of the neoadjuvant group consisted of 51 patients with MIBC, treated between March 2005 and June 2011, who were ineligible for cisplatin. Patients received 2 courses of GCarbo consisting of 800 mg/m2gemcitabine on days 1, 8, and 15, and carboplatin with an AUC of 4 on day 2. After GCarbo, radical cystectomy (RC) and bilateral pelvic lymph node dissection (PLND) were performed at an interval of 1 month. The cohort of RC alone included 59 cisplatin-ineligible MIBC patients treated with RC and bilateral PLND between June 1998 and February 2010. Propensity score matching was used to adjust for potential selection biases associated with treatment type. The endpoints were overall (OS) and disease-free survival (DFS). Results: Of the 51 patients who received GCarbo and RC, 6 (11.8%) RC specimens were found to be cancer free. Grade 3/4 neutropenia occurred in 17 patients (33.3%) and thrombocytopenia in 11 patients (21.6%). There were no patients who experienced grade3/4 nephrotoxicity or nausea. Propensity score-matched analysis indicated 45 matched pairs from both groups. The median follow-up period was 35.3 months. The 3-year OS rate was 86.5% for neoadjuvant GCarbo vs. 50.6% for the RC alone group (P < 0.0001). The DFS rate was 78.8% for neoadjuvant GCarbo vs. 44.8% for RC alone (P= 0.001). Multivariate analysis revealed that the neoadjuvant GCarbo regimen was an extremely strong and independent predictor of the longer OS and DFS. Conclusions: Although the present study is non-randomized, neoadjuvant GCarbo chemotherapy followed by immediate RC achieved significantly longer OS and DFS than cystectomy alone. The clinical usefulness of the present treatment for cisplatin-ineligible patients with MIBC should be verified by further trials.