Prognostic significance of race and tumor size in carcinosarcoma of gallbladder: a meta-analysis of 68 cases.

Carcinosarcoma of gallbladder, also named sarcomatoid carcinoma and spindle cell carcinoma, is a rare neoplasm. Its clinical features and prognostic determinants are still poorly understood due to its rarity. We identified 67 qualified cases in published literatures and 1 in our institution. 52 of them were females and 16 males (F:M=3.25:1). 27 were Japanese patients and the rest were mainly from the United States and Europe. The mean age was 68.8 years (median 68 years, range 45-91 years). The average tumor size was 6.9 cm (median 5 cm, range 1.0-24.0 cm, n=49). Adenocarcinoma was the most common epithelial component (79.2%) and squamous cell carcinoma was the least common (9.4%). Spindle cell type was the most common mesenchymal component (44.6%) and osteoid was the least common (5.4%). The mean survival was 17.5 months (median 5 months, range 0 to 85 months, n=56). The 1-year and 5-year survival rates were 19+/-5% and 16+/-5% (mean+/-SD), respectively. Kaplan Meier survival analysis was conducted to examine the prognostic value of various clinical parameters. We found Japanese patients had longer survival time than non-Japanese ones (mean=19.9 months vs 11.5 months, median=6 vs 4 months, n=27 vs 24, p=0.022). Patients with smaller tumor (<5.0 cm) had longer survival time (in months) than those with larger tumor (mean 26.6 vs 17.7, median 11 vs 5, n=14 vs 27, p=0.028). The presence of gallstone, epithelial and mesenchymal component types, age and sex of the patients were not significant prognostic factors. In summary, race (Japanese vs non-Japanese) and tumor size are important prognostic factors in carcinosarcoma of gallbladder and they may be used for prognostification.