Effect of signet-ring cell carcinoma histology on bladder cancer outcome.

Abstract

275 Background: Signet-ring cell carcinoma (SRCC) of the urinary bladder is a rare entity. Recent case series of the condition showed inconsistent results. We used a population-based data set to compare the cancer specific survival of patients with signet-ring cell carcinoma vs. transitional cell carcinoma (TCC) of the urinary bladder. Methods: Signet-ring cell carcinoma of the urinary bladder and transitional carcinoma of the urinary bladder were identified in the Surveillance, Epidemiology and End Results program (2001 to 2004). Demographic and pathological characteristics at diagnosis were compared. Differences in cancer specific survival were compared with univariate and multivariate Cox regression analysis. Results: A total of 103 SRCC cases were present in the database from 2001 to 2004. In that time 14,648 cases TCC cases were diagnosed. SRCC was more common in younger than in older patients (p <0.001); more commonly presented with high grade histology (p <0.001) and advanced stage disease (p <0.001). The 3-year cancer specific survival rate was 67.0% and 33.2% for TCC and SRCC, respectively. On multivariate analysis there was an increased mortality risk in patients with SRCC vs TCC (HR 1.42, 95% CI 1.03–1.97, p <0.001). When only high grade cases of SRCC and TCC were compared, the risk was still worse in SRCC (HR 1.430, 95% CI 1.035–1.976, 0.03). When only local stage of SRCC and TCC were compared, the risk was worse in SRCC (HR 4.294, 95% CI 1.035–17.825, 0.045). Limited to patient who underwent cystectomy only, the difference in cancer specific survival disappeared (HR 1.289, 95% CI 0.771–2.155, 0.33). Conclusions: Even after adjusting for demographic, pathological and treatment factors, cancer specific survival is significantly worse in patients with SRCC than TCC. Further research into the biology of this rare tumor is required to explain these results. No significant financial relationships to disclose.