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

Background: Signet-ring cell carcinoma (SRCC) of the urinary bladder is a rare entity. No previous studies have directly compared the cancer-specific survival of patients with SRCC to patients with urothelial carcinoma (UC) of the urinary bladder.

Materials And Methods: Patients with diagnosis of urinary bladder SRCC and UC were identified in the Surveillance, epidemiology, and end results program (SEER) (2001-2004). Demographic of patients and clinical characteristics at diagnosis were compared. Differences in cancer-specific survival were compared using univariate and multivariate analysis.

Results: A total of 103 patients with SRCC and 14,648 patients with UC were indentified. Patients with SRCC were younger (P < 0.001), more commonly presented with higher-grade histology (P < 0.001) and advanced stage disease (P < 0.001), in comparison with patients with UC. The 3-year cancer-specific survival rate was 67.0% for patients with UC and 33.2% for SRCC. On multivariate analysis, there was an increased mortality risk in patients with SRCC versus UC (HR 1.49, 95% CI 1.11-2.00, P < 0.01).

Conclusions: Even after adjusting for demographic, surgical, and pathological factors, cancer-specific survival rate was significantly worse in patients with SRCC compared to UC. Further research into the biology of this rare tumor is required to explain these results.