Utilization and determinants of adjuvant therapy among older patients who receive curative surgery for pancreatic cancer

Objective:: We conducted a population-based study to describe the utilization, determinants, and survival effects of adjuvant therapies after surgery among older patients with pancreatic cancer. Methods:: Using Surveillance, Epidemiology, and End Results-Medicare data, we identified patients older than 65 years who received surgical resection for pancreatic cancer during 1992-2002. We constructed multiple logistic regression models to examine patient, clinical, and hospital factors associated with receiving adjuvant therapy. Cox proportional hazards models were used to examine the effect of therapy on survival. Results:: Approximately 49% of patients received adjuvant therapy after surgery. Patient factors associated with increased receipt of adjuvant therapy included more recent diagnosis, younger age, stage II disease, higher income, and geographic location. Hospital factors associated with increased receipt of adjuvant therapy included cooperative group membership and larger size. Adjuvant treatments associated with a significant reduction in 2-year mortality (relative to surgery alone) were chemoradiation or radiation alone but not chemotherapy alone. Conclusions:: Our findings suggest that adjuvant chemoradiation and, to a lesser degree, radiation only are associated with a reduction in the risk of mortality among older patients who undergo surgery for pancreatic cancer. However, receipt of adjuvant therapy varied by period and geography as well as by certain patient and hospital factors.