Primary squamous cell carcinoma of the pancreas: an update on a rare neoplasm from the SEER database

IntroductionPancreatic squamous cell carcinoma is a rare type of pancreatic cancer of ductal origin, composing an estimated 0.5 - 5% of pancreatic ductal malignancies. As a result, epidemiology, treatment options, and associated outcomes are poorly understood and understudied. Our aim was two-fold: to evaluate demographic trends and analyze overall survival (OS) associated with different treatment modalities for this rare malignancy.MethodsPatients with pancreatic squamous cell carcinoma diagnosed between 1992 and 2019 were eligible and reviewed utilizing the Surveillance, Epidemiology, and End Results Registry (SEER) database. Data was analyzed using SPSS and python packages lifelines and pandas. Variables of interest included stage at diagnosis as well as the receipt of surgery, radiotherapy, and/or chemotherapy. Five-year OS curves were analyzed using Kaplan-Meier probability stratified by treatment modality.ResultsOf 342 cases of pancreatic squamous cell carcinoma, 170 (49.7%) were females and 172 (50.3%) were males. 72 (21.1%) of patients received radiotherapy, 123 (35.9%) patients received chemotherapy, and 47 (13.7%) received surgery. Patients who were diagnosed under the age of 50 had prolonged survival time compared to those diagnosed over the age of 50 (12 vs 8 months, respectively, p < 0.001). This trend was evident despite the lack of a significant association between age at diagnosis and presence of metastases (p = 0.524). The median OS was 3 months for the entire cohort and there was a significant difference in median survival time noted across treatment modalities: OS was prolonged in those receiving surgery compared to those receiving chemotherapy or radiotherapy alone (30 vs 2 months, respectively, (p