Neoadjuvant treatment with trastuzumab and folfox induces a complete pathologic response in a metastatic ERBB2 (HER2)-Amplified Duodenal Cancer

Abstract

Overexpression of HER2 protein and amplification of the ERBB2 gene has been observed in various adenocarcinomas, providing a therapeutic target that can be used to extend the survival of a select cohort of patients. Anti-HER2 therapy has been successfully applied to gastric and colorectal cancers, but its use and potential benefit in small intestinal carcinomas is not well characterized. We applied anti-HER2 therapy to an ERBB2-amplified advanced duodenal adenocarcinoma, adding trastuzumab to FOLFOX in the neoadjuvant setting. A 61-year-old woman with an advanced duodenal cancer harboring an ERBB2 amplification received preoperative trastuzumab and FOLFOX. Restaging revealed significant tumor downstaging with no metastasis. After multidisciplinary assessment, she underwent pancreaticoduo-denectomy. Final pathologic analysis revealed no residual invasive adenocarcinoma, consistent with a complete neoadjuvant treatment response. This case report emphasizes the need for further molecular characterization of small bowel cancers; genetic alterations may provide therapeutic targets to improve the prognosis of these rare and aggressive malignancies.