Background and objective: Previous studies indicated cancer survivors had a higher risk of developing subsequent pancreatic ductal adenocarcinoma. However, the influence of prior cancer on survival outcomes of current pancreatic cancer remains unclear.
Methods: Eligible populations were selected from the Surveillance, Epidemiology, and End Results programs from 2000 to 2012. We adopted Kaplan-Meier curves and Cox analysis to compare survival differences between patients with and without prior cancer.
Results: Overall, 67,555 pancreatic cancer patients, including 5582 (8.26%) with and 61,973 (91.74%) without prior cancer, were included. The most common types of prior cancers were prostate, breast, and colorectal cancers. The median time from diagnosis of an initial malignancy to subsequent pancreatic cancer was 59.8 months. Patients with a prior cancer had higher overall one-year and three-year survival rates compared with those without a prior cancer. Multivariable Cox analysis demonstrated that a history of prior malignancy could independently predict the better overall survival outcome of pancreatic cancer (HR = 0.92, 95% CI, 0.89-0.94, p < 0.001), especially for colorectal, breast, corpus uteri and prostate cancer survivors.
Conclusions: A history of cancer did not contribute to a poor survival outcome for patients with pancreatic cancer. More prospective trials might be warranted to validate our findings.
Keywords: Pancreatic ductal adenocarcinoma; SEER; population-based study; prior cancer history; survival outcomes.