Primary tumor resection in the setting of unresectable metastatic disease in small bowel NETs: consensus and controversy.

Abstract

Small bowel neuroendocrine tumors represent a rare malignancy, and most patients present with metastatic disease at diagnosis. While current guidelines from the North American Neuroendocrine Tumor Society and the European Neuroendocrine Tumor Society agree that resection is indicated for symptomatic tumors causing obstruction, ischemia, or bleeding, the role of primary tumor resection in otherwise asymptomatic patients with unresectable metastatic disease remains controversial. This article reviews the existing evidence and highlights the role of primary tumor resection in the setting of metastatic disease. Retrospective studies support mixed findings: some boast a survival advantage for patients undergoing resection of the primary tumor, while others caution that other prognostic factors, including those related to tumor biology, are the true drivers of this benefit. However, it is known that many patients are not truly asymptomatic if a thorough history and physical is performed, and symptom burden can become significant over time. Upfront resection of the primary small bowel tumor prevents development of local complications, such as bowel obstruction or mesenteric vascular compromise, which may require emergency surgery. It has been shown that patients who underwent surgery in the emergent setting (as opposed to elective) had worse survival outcomes and tended to have more incomplete tumor resection and a significantly smaller lymph node yield. Nonetheless, the absence of prospective or randomized controlled studies leaves the value of primary tumor resection unproven, underscoring the critical need for well-designed trials incorporating quality-of-life metrics and obstruction-free survival as key patient-centered outcomes.