Neoadjuvant chemotherapy in small cell urothelial cancer improves pathologic downstaging and long-term outcomes: results from a retrospective study at the MD Anderson Cancer Center.

BACKGROUND: Small cell urothelial carcinoma (SCUC) is a rare, aggressive malignancy with a propensity for early microscopic metastases. Data suggest that neoadjuvant chemotherapy may lead to improved survival compared with initial surgery.
OBJECTIVE: To determine the influence of neoadjuvant chemotherapy on survival of SCUC patients in a large single-institution cohort. DESIGN, SETTING, AND PARTICIPANTS: Between 1985 and 2010, 172 patients were treated for SCUC at MD Anderson Cancer Center (MDACC). Clinical, pathologic, and surgical data were collected and analyzed. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Overall survival (OS) and disease-specific survival (DSS) were calculated using the Kaplan-Meier method. Multivariable Cox proportional hazards models were used to evaluate the effects of neoadjuvant chemotherapy on survival. RESULTS AND LIMITATIONS: Of 125 patients with resectable disease (≤ cT4aN0M0), 95 were surgical candidates. Forty-eight received neoadjuvant chemotherapy, and 47 underwent initial surgery. Neoadjuvant treatment was associated with improved OS and DSS compared with initial cystectomy (median OS: 159.5 mo vs 18.3 mo, p<0.001; 5-yr DSS: 79% vs 20%, p<0.001). Neoadjuvant chemotherapy resulted in pathologic downstaging to ≤ pT1N0 in 62% of tumors compared with only 9% treated with initial surgery (odds ratio: 44.55; 95% confidence interval, 10.39-191). Eight patients with clinically node-positive disease had surgical consolidation with cystectomy and extended lymph node dissection after clinical complete response to chemotherapy. Median OS and DSS in this group of patients were 23.3 mo and 21.8 mo, respectively, with 5-yr OS and DSS of 38%.
CONCLUSIONS: Neoadjuvant chemotherapy is associated with a high rate of pathologic downstaging and correlates with significantly higher survival compared with historical expectations. Although limited by a small sample size and retrospective analysis, in the context of a rare disease, this experience suggests neoadjuvant chemotherapy as a standard approach in treating SCUC.