Prognostic significance of trophoblastic cell surface antigen 2 expression and pathologic parameters in patients with ampullary adenocarcinoma

Trophoblastic cell surface antigen 2 (TROP2) has been reported to be up-regulated in several types of carcinomas and is associated with aggressive behavior and poor survival. However, TROP2 expression and its clinical significance in ampullary adenocarcinoma (AA) have not been investigated. We examined TROP2 expression by immunohistochemistry in 112 patients with AAs. The associations of TROP2 expression with clinicopathologic characteristics were evaluated by χ² analyses or Fisher's exact tests. The associations of TROP2 expression and pathologic parameters with survival were evaluated by the Kaplan-Meier method and univariate and multivariate Cox regression analyses. Eighty-six AAs (76.8%) were positive for TROP2, which showed a membranous and cytoplasmic staining. TROP2 expression was associated with higher frequency (P = .04) and higher number (P = .03) of lymph node metastasis, higher pN stage (P = .03), less frequent adenoma (P = .04), and higher frequency of recurrence/metastasis (P = .004). TROP2 expression was associated with shorter disease-free survival (P = .02) and overall survival (P = .03). TROP2 expression was an independent prognostic factor for disease-free survival (P = .04). We demonstrated that TROP2 was expressed in 76.8% of AAs. TROP2 expression was associated with higher frequency and high number of lymph node metastasis and higher pN stage. More importantly, TROP2 expression was associated with higher frequency of recurrence/metastasis, shorter disease-free and overall survival and was an independent prognostic factor for disease-free survival. Our results suggest that TROP2 may be used both as a prognostic marker and as a therapeutic target for patients with AAs.