Immunohistochemical expression of CDX2, CK7, HER2 and HER4 in periam- pullary adenocarcinoma : implications for clinicopathology and patient outcomes

Background : Periampullary carcinomas originate from the pancreatic head, the ampulla, the distal bile duct, or the duodenum. The expression of CK7 and CDX2 has been used in the classification of periampullary carcinomas. There is prognostic value of human epidermal growth factor receptor (HER) 2 and HER 4, which have been linked to poor prognosis in several types of tumors, such as breast and gastric carcinomas. We aimed to evaluate the expression and prognostic value of CDX2, CK7, HER 2, and HER 4 in periampullary adenocarcinoma. Patients and Methods : We retrospectively selected 98 patients who had undergone pancreatoduodenectomy for periampullary adenocarcinoma at our pathology department. The tumor location, pathological subtype, involvement of vessels and lymph nodes, perineural invasion, clinical follow-up, and tumorstage were noted. Immunohistochemistry was performed for CK7, CDX2, HER2, and HER4. Results : CDX2 staining was predictive of perineural invasion. Additionally, there was a significant association between the overexpression of HER2 and HER4 and the presence of perineural invasion. HER4 was significantly positive in patients with the pancreatobiliary subtype compared with patients with the intestinal subtype. Patients with the pancreatobiliary subtype, lymph node involvement, and advanced pT and UICC stages had significantly lower median survival. Conclusion : Our findings suggest that only pancreatobiliary subtype, lymph node involvement and advanced pT and UICC stages were independent predictors of short survival, but the ampulla tumor location predicted a significantly better survival time. The immunohistochemical expression of CDX2, CK7, HER4, and HER2, vessel involvement, and perineural invasion were not associated with the survival of patients with periampullary adenocarcinoma. (Acta gastroenterol. belg., 2017, 80, 31-37).