Histology shift in esophageal cancer between biopsies and resections after neoadjuvant therapy: a pilot study

Abstract

Abstract Background Preoperative neoadjuvant therapy followed by resection is the mainstay treatment for locally advanced esophageal adenocarcinoma (EAC). We recently observed the histology shift from predominant EAC in the biopsy to neuroendocrine neoplasm (NEN) with or without EAC in the post-treatment esophagectomy. The underlying mechanism of this finding is uncertain and there is limited information in the literature. Methods Cases with a biopsy diagnosis of EAC and resection diagnosis of NEN with or without EAC were retrieved. All H&E slides were reviewed in conjunction with clinical history and ancillary studies. Results A total of 11 patients were identified with a median age of 60 years. Ten patients received presurgical chemoradiation therapy and 1 with chemotherapy only. All biopsies revealed conventional EAC. When neuroendocrine immunomarkers were retrospectively performed on 5 biopsies, two showed focal positivity, although the classic neuroendocrine morphology was not readily appreciated. The neuroendocrine neoplasm ranged from 1% to 100% in the resections, including 8 of well differentiated NETs and 3 of neuroendocrine carcinomas (NECs). Six cases were clinical stage III or above. Upon follow up, eight patients died of the disease (median survival = 26 months) and three patients were alive after a median follow-up of 14 months. The overall median survival time was better than the reported esophageal NEC (15 months). The 5-year observed survival rate was 11.3%, which was lower than the SEER 5-year survival rate of EAC (21.8%). Conclusions We reported a small series of EAC that showed histology changes between biopsy and esophagectomy after receiving neoadjuvant therapy. These patients tended to present with advanced stage of disease and poor prognosis. Acknowledging this unique phenomenon is helpful to solve diagnostic dilemma and potentially guide presurgical therapy to improve patient’s survival. The abstract of this study was presented at the Annual Conference of United States and Canadian Academy of Pathology (USCAP), March 2023, New Orleans, LA