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

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. 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. 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). 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.