Low MUC4 expression is associated with survival benefit in patients with resectable pancreatic cancer receiving adjuvant gemcitabine

Background: Previous in vitro studies have shown that mucin 4 (MUC4) confers resistance toward gemcitabine in pancreatic cancer cells. To date, there are few clinical studies corroborating these findings. The aim of this study was to evaluate the predictive impact of MUC4 expression on survival in patients with resectable pancreatic cancer receiving adjuvant gemcitabine. Materials and methods: MUC4 expression was investigated by immunohistochemistry in 78 tissue sections from patients with pancreatic ductal adenocarcinoma undergoing Whipple resection. The H-score was used to evaluate MUC4 expression. The Kaplan-Meier method and Cox proportional hazards regression analysis were used to assess the predictive role of MUC4 expression. Results: The MUC4 protein was expressed in 93.6% (73/78) of pancreatic cancer tissue specimens. None of the normal control pancreatic tissues had any MUC4 expression. Low MUC4 expression (H-score <= 100) was detectable in 42 (53.8%) of tumors and high MUC4 expression (H-score >100) was detectable in 36 (46.2%) of tumors. Low expression of MUC4 was associated with favorable survival (p=.027), whereas high MUC4 expression did not correlate with survival (p=.87) in patients receiving adjuvant gemcitabine treatment. Conclusions: This is the first study indicating a predictive role of MUC4 expression for gemcitabine treatment in the clinical setting.