Most of pancreatic neuroendocrine carcinoma (PanNEC) present with distant metastases. Removal of the primary tumor is not recommended for metastatic PanNEC patients considering the limited survival benefit compared to well differentiated grade patients. However, published data to support these recommendations regarding PanNEC are scarce. The aim of this study was to assess whether resection of the primary tumor in patients with stage IV PanNEC has an impact on survival.
Patients with stage IV PanNEC registered in the Surveillance, Epidemiology, and End Results database between 1973 and 2014 were identified. The specific criteria are as follows:1 The histologic subtypes and their ICD-O-3: large cell neuroendocrine carcinoma(8013), small cell carcinoma(8041) and neuroendocrine carcinoma (8246); 2 histologic differentiation grade: poorly differentiated and undifferentiated; 3 Diagnostic confirmation is “Positive histology“; 4 the age ≥ 18 years and ≤ 85 years; 5 “SEER historic stage” variable is“distant”or AJCC stage IV;6.Survival months flag is ”Complete dates are available and there are more than 0 days of survival”. Overall (OS) and cancer-specific survival (CSS) of patients who did and did not undergo resection of their primary tumor were compared by means of risk-adjusted Cox proportional hazard regression analysis and propensity score matched analysis.
We identified 461 patients with metastatic PanNEC and survival data. 15.8% (73/461) of patients had surgical removal of their primary tumor. Median survival of patients undergoing primary tumor resection was 28 (95% CI: 4.751-51.249) versus 6 (95% CI: 4.672-7.328) months for those without resection (p < 0.0001). Patients underwent primary tumor resection showed a significant benefit in both OS (HR of death=0.296, 95%CI 0.206–0.424, p < 0.001) and CSS (HR of death=0.329, 95 % CI 0.219–0.493, p < 0.001) in unadjusted multivariate Cox regression analysis; the benefit persisted after propensity score adjustment.
The recent recommendations judging resection of the primary as inadvisable and the accompanying trend towards fewer palliative resections of the primary tumor in IV stage PanNEC have to be contested.
Clinical trial identification
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The author has declared no conflicts of interest.