Primary signet ring cell adenocarcinoma of the bladder with elevated serum carbohydrate antigens 19-9 and 50

Clinical characteristics and outcomes of patients with primary signet-ring cell carcinoma of the urinary bladder

OBJECTIVE

The aim of this study was to examine the epidemiology, natural history, treatment pattern and predictors of long-term survival of patients with signet-ring cell carcinoma (SRCC) of the urinary bladder based on the analysis of the national Surveillance, Epidemiology, and End Results (SEER) database.

METHODS AND RESULTS

In total, 230 patients with pathologically confirmed SRCC of the urinary bladder were identified between 1973 and 2004. The mean age was 65 ± 13 years. Overall, 75.7% of the patients had a poorly differentiated or undifferentiated histology grade, 26.5% presented with metastatic disease, 59 (25.7%) underwent transurethral resection for bladder tumor only and 107 (46.5%) had partial or radical cystectomy. The 1-, 3- and 10-year cancer-specific survival rates were 66.8, 40.6 and 25.8%, respectively. Using multivariable Cox proportional hazard model, age (HR 1.024; p = 0.004), stage (distant vs. local, HR 6.2; p < 0.001) and cystectomy (HR 0.53; p = 0.002) were identified as independent predictors for cancer-specific survival.

CONCLUSIONS

Receipt of cystectomy was strongly associated with improved survival in the patients with SRCC of urinary bladder. However, many patients with localized tumors did not receive potentially curative cystectomy. Further studies to address the barriers to the delivery of appropriate care to these patients are warranted.

Dedifferentiation of adenocarcinomas by activation of phosphatidylinositol 3-kinase

Signet ring cell carcinoma is a malignant type of poorly differentiated adenocarcinomas in stomach, which is characterized by the occasional presence of signet ring-like cancer cells. We found that expression of constitutively active phosphatidylinositol 3-kinase (PI 3-kinase) in well differentiated adenocarcinoma cell lines induced the loss of cell-cell contact and some of the cells changed their shapes to signet ring cell-like, characterized by appearance of mucus droplets in the cytoplasm with well developed endplasmic reticulum and Golgi complexes. The active PI 3-kinase-expressing cells formed poorly differentiated tumors in nude mice, which were clearly different from those of the original cell lines. The PI 3-kinase activities detected in anti-phosphotyrosine immunoprecipitates were higher in several signet ring cell carcinoma-derived cell lines than in other adenocarcinoma cell lines. In addition, PI 3-kinase was found to be associated with a 200-kDa protein phosphorylated in tyrosine in 4 of 6 signet ring cells but not in other cell lines, suggesting that PI 3-kinase is possibly activated in these cells by binding to the 200-kDa protein. The 200-kDa protein-PI 3-kinase complex was exclusively fractionated in the membrane fractions. The specific activity of the PI 3-kinase immunoprecipitated with anti-phosphotyrosine antibody was approximately 3-fold higher than that with anti-PI 3-kinase antibody. These results suggest that PI 3-kinase in signet ring cell carcinoma is recruited to the membrane and activated by the binding to the 200-kDa protein.