Trends in survival based on treatment modality in patients with pancreatic cancer: a population-based study
Background Pancreatic cancer (PC) is one of the most lethal types of cancer and surgery remains the most optimal treatment modality for patients with resectable tumors. The objective of this study is to examine and compare the trends in survival rate among PC patients based on treatment modality.
Methods This population-based retrospective analysis included all patients with known stage for PC in Ontario, Canada between 2007 and 2015. Flexible parametric models were used to conduct survival analysis. Survival rates were calculated based on treatment modality, while adjusting for patient and tumor specific covariates.
Results In total, 6437 patients were included in this study. More than half of the patients aged 80 and over received no curative treatment. The proportion of patients receiving chemoradiation decreased over time. The 1-, 2- and 5-year survival rates increased 30-40% for stage I disease and less than 15% for stage II over the study period. Noticeable increases in 1-, 2, and 5-year survival rates were observed for patients underwent for distal pancreatectomy and Whipple procedures. There were no changes in survival for stage III and IV disease from 2007 to 2015.Conclusions A majority of cases for PC continue to be diagnosed in late stage, with poor short-term and long-term prognosis. The survival for stage I tumors and surgical modalities increased over time without any evidence of changes in stage distribution. We speculate that improvements in chemotherapy modalities and adoption of quality standards for surgical resection could be attributed for the positive trends in survival.