Chemotherapy and Supportive Care Practice Patterns Among Older Adults With Metastatic Pancreatic Cancer.

[PURPOSE] Metastatic pancreatic ductal adenocarcinoma (mPDAC) is a leading cause of cancer mortality in the United States. Although fluorouracil, leucovorin, irinotecan, and oxaliplatin (FOLFIRINOX) and gemcitabine with NAB-paclitaxel (GnP) represent first-line chemotherapy options for mPDAC, practice patterns in older adults remain understudied. We describe national treatment trends, factors associated with treatment selection, and receipt of second-line treatment in older adults with mPDAC.

[METHODS] Using the SEER-Medicare linked database (2010-2019), we identified a cohort of individuals age 66 years and older diagnosed with mPDAC who initiated infusion chemotherapy within 90 days of diagnosis. Temporal trends in first-line treatment selection were quantified for the overall population and stratified by levels of a claims-based frailty index (robust, prefrail, and frail). We used multinomial logistic regression to describe associations between patient factors and first-line agent received adjusted for year of diagnosis. We characterized median time on first-line therapy, use of supportive care interventions, and receipt of second-line therapy.

[RESULTS] Among 7,473 adults with mPDAC (median age = 74 years, 50.7% female), gemcitabine monotherapy was the predominant treatment in 2010 at 69.3%, but in 2019 it fell to the third most-used regimen (16.6%) behind GnP (45.2%) and FOLFIRINOX (20.9%). In the most recent data (2019), 29.8%, 19.8%, and 6.8% of robust, prefrail, and frail individuals received FOLFIRINOX, respectively. Factors associated with regimen selection included age, sex, race/ethnicity, comorbidity, and frailty. Approximately one third of FOLFIRINOX initiators received second-line GnP (36.3%) and vice versa (31.1%).

[CONCLUSION] Chemotherapy use has evolved for older adults with mPDAC and varies across levels of baseline frailty. The heterogeneity in chemotherapy selection and practice patterns in older adults merits ongoing investigation to help ensure patients receive treatment tailored to their unique geriatric needs.