Patients with non-functional metastatic G2 pancreatic neuroendocrine tumor benefit from palliative surgery: A 20-year single-center retrospective analysis

Pancreatic neuroendocrine tumor (pNET) is the most common subset (31.5%) of gastroenteropancreatic neuroendocrine tumor in China. Based on real-world data from a single center, the present study aimed to evaluate the influence of clinical characteristics, medical treatment and surgery on the survival of non-functional metastatic G2 pNET. In total, 114 metastatic non-functional G2 pNET patients, who were treated and followed up in the Department of Medical Oncology, Peking Union Medical College Hospital (PUMCH) from 2001 until 2019, were analyzed retrospectively. The primary endpoint, overall survival (OS), was calculated from the date of diagnosis to the date of death. The second endpoint, progression-free survival (PFS), was calculated from the date of diagnosis to the date of disease progression. Statistical data were analyzed to evaluate the effects of a clinical characteristic, medical treatment and surgery on OS and PFS. Sixty-nine (60.5%) patients were male and 87 (76.3%) were aged < 60 years. The liver was the most common metastatic organ, with a total of 84 cases (73.7%). With respect to surgery, 32 (28.1%) patients underwent radical surgery and 37 (32.5%) underwent palliative surgery. Survival analysis showed that the 5-year and 10-year survival rates were 79.36% and 70.0%, respectively. Univariate and multivariate Cox regression analyses suggested that both radical (p < .001/.003) and palliative surgery (p < .001/.002) significantly prolonged OS, as revealed by the Kaplan-Meier test (p < .001). Subgroup analysis showed that palliative resection also significantly improves the prognosis in patients with multiple liver metastases. However, the first-line systemic anti-tumor therapy option showed no statistical differences in the present study. Overall, patients with non-functional metastatic G2 pNET receiving palliative or radical surgery demonstrated significantly better survival. Prospective clinical trials are suggested to validate our findings.