Do Patients Diagnosed with Metastatic Pancreatic Cancer Benefit from Primary Tumor Surgery? A Propensity-Adjusted, Population-Based Surveillance, Epidemiology and End Results (SEER) Analysis

BACKGROUND: With the progress in surgical techniques and management of complications, pancreatic resection can be safely performed in experienced hospitals. Pancreatic resection enables surgeons to assess the effect of surgery for metastatic cases, even when there is limited information. In the present study we evaluated the role of primary tumor resection for metastatic pancreatic cancer (mPC) by using the Surveillance, Epidemiology and End Results (SEER) database. MATERIAL/METHODS: Metastatic pancreatic cancer patients treated at our hospital from 2004 to 2015 were identified. The effect of surgery on cancer-specific survival was assessed by restricted mean survival time (RMST) and stabilized inverse probability of treatment weight-adjusted analysis after propensity score matching (PSM). RESULTS: A total of 2694 mPC patients were included. Of this population, 365 adults underwent primary tumor resection. After propensity matching, postsurgical patients had longer RMST than non-surgery patients (1: 1 PSM 11.60 months vs. 8.98 months; 1: 2 PSM 11.61 months vs. 9.10 months; p<0.01). Stabilized inverse probability of treatment weight-adjusted analysis yielded similar results (p<0.01). CONCLUSIONS: Our study supports the hypothesis that patients with mPC can benefit from primary tumor surgery. However, the surgical inclusion criteria and the appropriate role of surgery, such as its effect on symptom control, quality of life, and the extent to which it prolongs survival for metastatic pancreatic cancer, remain to be completely assessed by well-designed, prospective, randomized clinical trials.