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. Citation: Maekawa H, Sato K (2019) Efficacy of Adjuvant Chemotherapy for Fatty Acid Synthase-Positive and Negative Distal Bile Duct Cancer and Ampullary Cancer: A Retrospective Analysis. J Cancer Sci Ther 11: 057-062. doi: 10.4172/1948-5956.1000584 J Cancer Sci Ther, an open access journal ISSN: 1948-5956 Volume 11(2) 057-062 (2019) 58 Figure 2: The prognoses of distal bile duct cancer according to node involvement (A) Relapse-free survival curve of node-positive and -negative cases, the relapsefree survival of node-positive cases was shorter than that of node-negative cases (50% relapse-free survival was 7 months and undefined, respectively, p=0.0002) (B) Overall survival curve of node-positive and -negative cases, there was no significant difference between node-positive cases and node-negative cases (mean survival time was 22 months and 60 months, respectively, p=0.0925). Figure 1: Immunohistochemical FAS expression (A) FAS staining of adipocytes, adipocytes were stained for FAS. The thin and round cytoplasm of adipocytes had a strong positive stain (100x) (B) a FAS-positive stained case, immunohistochemically, over one-third of the tumor cells were positive, which means it was counted as a FAS-positive case (100x distal bile duct cancer, adenocarcinoma) (C) a FAS-negative stained case, immunohistochemically, less than one-third of the tumor cells were positive, which means it was counted as a FAS-negative case (100x distal bile duct cancer, adenocarcinoma). defined as positive staining in less than one-third of tumor cells (Figure 1). Chemotherapy histories and prognoses were obtained from patient medical records. Statistical analysis Statistical analysis was performed using a log-rank test. All analyses were conducted using Graph Pad Prism5® statistical software (Graph Pad Software Inc., La Jolla, CA, USA). A p-value less than 0.05 was considered significant. The study protocol conformed to the ethical guidelines of the World Medical Association Declaration of Helsinki and was approved by the Ethical Committee of our hospital.