Disparities in survival by stage after surgery between pancreatic head and body/tail in patients with nonmetastatic pancreatic cancer

BACKGROUND: The survival of pancreatic cancer patients with lesions in different locations is unclear. In addition, the different surgery types for nonmetastatic pancreatic head cancer (PHC) or body/tail cancer (PBTC) have different prognostic influences. We analyzed the association by stage between tumor location (head vs. body/tail) and survival of nonmetastatic pancreatic cancer patients who underwent surgery. METHODS: We identified stages I to III pancreatic cancer patients who underwent surgery from 2004 through 2015 by using the Surveillance, Epidemiology, and End Results (SEER) database. The adjusted hazard ratio (HR) and 95% confidence interval (CI) for cancer-specific survival (CSS) were obtained using Cox regression. RESULTS: A total of 13517 patients or 86.6% had PHC. PHC patients were more likely to have an advanced tumor stage, higher tumor grade, and more frequent and a higher number of positive lymph nodes compared with PBTC patients. The PHC patients had a worse CSS than PBTC patients (P<0.001) and were predominantly at stage I (P = 0.008) and II (P = 0.004). Multivariate Cox regression analysis showed that PHC was an independent prognostic factor associated with a worse CSS in pancreatic cancer patients (HR 1.132, 95% CI 1.042–1.228, P = 0.003), predominantly at stage II (HR 1.128, 95% CI 1.030–1.235, P = 0.009). CONCLUSION: At a resectable early stage, the PHC patients had a worse CSS than PBTC patients after surgery. PHC was an independent prognostic factor associated with worse survival in pancreatic cancer patients, predominantly at stage II.