Comparative study of clinicopathological significance, BIRC7, and STC2 expression between squamous cell/adenosquamous carcinomas and adenocarcinoma of gallbladder.

Gallbladder cancers (GBCs) are uncommon, but highly aggressive cancers. The majority of GBCs are adenocarcinomas (ACs), but rare subtypes of GBCs such as squamous cell carcinoma (SC) and adenosquamous carcinoma (ASC) are observed as well. The clinicopathological characteristics of SC/ASC have not been well documented. Expressions of BIRC7 and STC2 were observed in some tumors. However, BIRC7 and STC2 expressions and clinical significances in gallbladder cancer have not been reported.In this study, the protein expressions of BIRC7 and STC2 in 46 SCs/ASCs and 80 ACs were measured using immunohistochemistry. We demonstrated that positive BIRC7 and STC2 expressions were significantly associated with large tumor mass (>3cm), high TNM stage and lymph node metastasis in SC/ASC and AC (p<0.05). Positive expression of BIRC7 was significantly associated with invasion of around tissues and organs in both SC/ASC and AC. Additionally, negative BIRC7 and STC2 expressions were significantly associated with surgical curability in AC. Univariate Kaplan-Meier analysis showed that BIRC7 and STC2 expressions, differentiation, tumor size, TNM stages, invasion, lymph node metastasis, and surgical curability were significantly associated with post-operative survival in both SC/ASC and AC patients(p < 0.001). Multivariate Cox regression analysis showed that positive BIRC7 and STC2 expressions are independent poor-prognostic factors in both SC/ASC and AC patients. Our study suggested that positive BIRC7 and STC2 expressions are closely correlated with clinical, pathological, and biological behaviors as well as poor-prognosis of gallbladder cancer.