Comparison of long-term survival between surgery-plus-chemotherapy and surgery- plus-chemoradiotherapy for high-grade gastrointestinal neuroendocrine tumors: a SEER-based study

Abstract

Abstract Background Specific treatment options for high-grade gastrointestinal neuroendocrine tumors (GI-NETs) remain controversial. The effects of surgery plus chemotherapy versus surgery plus chemoradiotherapy (CRT) on long-term survival in patients with GI-NETs were compared. Methods From the SEER-Medicare database, patients with GI-NETs (high-grade) who were diagnosed within 2004–2015 were selected. Relevant covariates adjustment and prognostic factors assessment were done using multivariate Cox regression models. Long-term survival between surgery plus chemotherapy and surgery plus CRT was distinguished using propensity score matching (PSM), Log-rank tests, and Kaplan-Meier curves. Results Among 839 patients with high-grade GI-NETs, 693 (82.6%) received surgery plus chemotherapy, and 146 (17.4%) received surgery plus CRT. In terms of in long-term outcomes, before PSM, a significant difference existed between surgery-plus-chemotherapy and surgery-plus-CRT. The overall survival (OS) (23 months versus 18 months, P = 0.016) and cancer-specific survival (25 months versus 20 months, P = 0.035) were higher in those who received surgery plus CRT compared to those who received surgery plus chemotherapy. After eliminating the imbalance of baseline variables using PSM, OS and CSS between the understudied patient groups were non-significantly different. Those who received surgery-plus-CRT had favorable prognosis in the subgroup with tumor sizes of 23–87 mm. Conclusion In terms of long-term survival, the results from SEER data showed no significant difference between patients administered surgery-plus-chemotherapy and surgery-plus-CRT. We need clinical randomized controlled trials to validate this result and to explore the best combination of surgery, chemotherapy, and radiotherapy based on different populations.