Abstract
BACKGROUND: Primary tumor resection (PTR) as a treatment option for patients with stage IV pancreatic cancer (PC) is controversial. PATIENTS AND METHODS: Stage IV PC patients, with treatment data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER), were screened. The main outcomes were overall survival (OS) and cancer-specific survival (CSS). RESULTS: We enrolled 15,836 stage IV PC patients in this study. Propensity score-matched analyses revealed improved OS and CSS of patients receiving chemotherapy plus PTR versus chemotherapy (median survival time [MST(OS) ]: 13 vs. 9 months, p = 0.024; MST(CSS) : 14 vs. 10 months, p = 0.035), and chemoradiotherapy plus PTR versus chemoradiotherapy (MST(OS) : 14 vs. 7 months, p = 0.044; MST(CSS) : 14 vs. 7 months, p = 0.066). Multivariate adjusted analyses further confirmed these results. Stratified with different metastatic modalities, multivariate analyses suggested that PTR significantly improved the OS and CSS among patients with ≤1 metastatic organ, and that patients with brain metastasis might not benefit from chemotherapy treatment. CONCLUSION: PTR improves the OS and CSS of stage IV PC patients on the basis of chemotherapy or chemoradiotherapy, provided that the metastases involve ≤1 organ. Chemotherapy, however, should be carefully considered in patients with metastases involving the brain.