Prognosis and treatment of primary urinary tract small cell carcinoma

Abstract

Objective To investigate the clinicopathological features, treatment modalities, and prognostic factors for survival in patients with urinary tract small cell carcinoma( UT-SCC). Methods A total of 25 patients treated from June 2000 to December 2014 were included in the retrospective study. The data included age, gender, primary tumors origins, stage, treatment modalities, progression-free survival(PFS), overall survival(OS), pathology and immunohistochemistry. Of these cases, 22 were male, and the other was female, whose age was 45-79 years (mean age 67). 20 cases small cell carcinoma of bladder patients and 2 small cell carcinoma of prostate cancer patients were included. The number of small cell carcinoma in pelvis, ureter and retroperitoneal was 1 respectively. The patients with small cell carcinoma of the urinary tract were classified as disease and extensive disease. 17 bladder small cell carcinomas were limited disease and 3 cases were extensive disease; Prostate small cell carcinomas were both extensive disease; The small cell carcinomas in pelvis, ureter were limited disease; The small cell carcinoma in retroperitoneal was extensive disease. 10 bladder small cell carcinomas which were limited disease received radical cystectomy. 6 of 10 patients received etoposide and cisplatnum (EC). 4 of 10 patients received gemcitabine and cisplatnum (GC). 7 bladder small cell carcinomas patients who with limited disease refused to receive radical cystectomy in which 2 patients received TURBT and 5 patients received TURBT followed chemotherapy. Both prostate small cell carcinomas received chemoradiotherapy. 2 small cell carcinomas in upper urinary tract (pelvis and ureter) received radical nephroureterectomy with bladder cuff resection. The patient of retroperitoneal small cell carcinoma received percutaneous nephrostomy after biopsy. The progression-free survival (PFS) and overall survival (OS) of these patients are analyzed; the influence of TURBT with adjuvant chemotherapy and clinicopathologic characteristics were analyzed in median PFS and OS. PFS and OS were compared between groups as a function of time, using a Kaplan-Meier survival curve analysis and the log-rank significance test. All statistical tests were two-sided, and P values < 0.05 were considered statistically significant. Results 25 patients with a pathologic confirmation of UT-SCC, either by biopsy or surgery, were finally included. These patients were classified as pure UT-SCC (14) and Mixed UT-SCC (11). Mixed UT-SCC was defined as tumors containing both SCC and non-SCC components, regardless of the proportion of the latter. 13 cases were strongly positive and 3 cases were weakly positive in neuron specific enolase (NSE) level. 8 cases were strongly positive and 2 cases were weakly positive in CgA level. Patients with limited disease experienced a significant longer PFS and OS compared with extensive disease subjects (PFS 13.2 vs. 7.8 χ2=13.53 P<0.01; OS 27.2 vs. 12.7 χ2=19.88 P<0.01). Patients with bladder SCC showed a significantly higher median PFS and OS compared with patients with SCC of other parts of urinary tract (PFS 12.8 vs. 8.2 χ2=12.00, P=0.001; OS 26.3 vs. 13.2 χ2=14.45, P<0.01). The two different chemotherapy regimens (GC and EC) have no influence on survival (PFS: 16.3 vs.12.5, χ2=3.34, P=0.07; OS 29.5 vs.22.8, χ2=1.66, P=0.198). TURBT followed by adjuvant therapy have no influence on survival (PFS 14.5 vs.12.0 t=1.30 P=0.251; OS 24.5 vs. 28.4 t=0.50, P=0.636). Conclusions The primary tumors origins and stage may have influence on survival in patients with UT-SCC. Patients with bladder small cell carcinoma and limited disease experienced a longer survival. Key words: Urological neoplasms; Small cell carcinoma; Treatment; Prognosis