Value of thyroid cancer history in the prognosis of pancreatic cancer: a SEER population-based study

Thyroid cancer patients have a good prognosis, and their long survival increases the likelihood of developing a second primary tumor. Meanwhile, pancreatic cancer (PC) has a poor prognosis and therapeutic efficacy. However, the association between prior thyroid cancer and the subsequent PC prognosis is unknown. Herein, we selected pathologically diagnosed PC patients older than 17 between 2010 and 2015 from the SEER database. We used propensity score matching (PSM) to reduce confounding factors between groups and matched each PC patient with a history of thyroid cancer with 10 PC patients without a history of thyroid cancer. Finally, we selected 103 PC patients with prior thyroid cancer and 1030 PC patients without prior thyroid cancer. Then, we analyzed the factors influencing the overall survival (OS) and the cancer-specific survival (CSS) of PC patients. The median overall survival of PC patients with and without a history of thyroid cancer was 12 and 9 months, respectively. The history of thyroid cancer in PC patients reduced the PC-specific mortality (p < 0.05). Prior thyroid cancer might be a favorable prognostic factor for PC-specific mortality in PC patients.