Efficacy of Adjuvant Chemotherapy for Fatty Acid Synthase-Positive and Negative Distal Bile Duct Cancer and Ampullary Cancer: A Retrospective Analysis

Abstract

Objective: Immunohistochemical fatty acid synthase expression is a prognostic marker in several cancers and is related to cancer aggressiveness. Here, we analyzed fatty acid synthase expression as an indicator of adjuvant chemotherapy for distal bile duct and ampullary cancer cases. Methods: Forty-three cases of distal bile duct cancer and thirty-seven ampullary cancer cases resected between 2000 and 2017 were examined. We investigated immunohistochemical fatty acid synthase expression in resected specimens and the involvement of lymph nodes. We compared these findings with patient prognosis using medical history of postoperative adjuvant chemotherapy. Patient survival was expressed by the Kaplan-Meyer method and analyzed by a log-rank test. Results: There were twenty-two fatty acid synthase-positive cases for distal bile duct cancer and seventeen for ampullary cancer. For distal bile duct cancer cases, the relapse-free survival and overall survival of fatty acid synthase-positive cases were shorter than those for fatty acid synthase-negative cases (p=0.0094 and p=0.0327, respectively). For ampullary cancer cases, the relapse-free survival and overall survival of fatty acid synthasepositive cases were also shorter than those for fatty acid synthase-negative cases (p=0.0225 and p=0.0103, respectively). Adjuvant chemotherapy occurred in twelve of the twenty-two fatty acid-positive distal bile duct cancer cases and in eight of the seventeen fatty acid-positive ampullary cancer cases. Relapse-free survival and overall survival of cases with adjuvant chemotherapy did not differ from those without adjuvant chemotherapy in both distal bile duct cancer and ampullary cancer. Conclusion: Although fatty acid synthase expression was a prognostic factor in bile duct cancer and ampullary cancer, it was not an indicating marker for adjuvant chemotherapy.