MK-1 expression in carcinoma of the ampulla of Vater as a predictor of improved prognosis after surgical resection

This retrospective study investigated the prognostic significance of MK-1 expression in human carcinoma of the ampulla of Vater (CAV). Expression was examined immunohistochemically using specimens from 38 patients who underwent surgical treatment for CAV. Expression was found in 61% of samples. Thirteen of 15 well-differentiated but only two of eight poorly differentiated adenocarcinoma were positive (P=0.0352). MK-1 positivity tended to show significantly decreasing pT (P=0.0039), pN (P≤0.001), and pStage (P=0.001). Multivariate analysis showed that MK-1 expression is an independent prognostic marker (P=0.0097) and Kaplan–Meier curves showed a significant relationship with increased overall survival (P=0.0137). These results suggest that MK-1 expression is a prognostic marker of CAV.