Adjuvant therapy in patients with resected pancreatic adenocarcinoma: Analysis of treatment allocation patterns in a Canadian provincial institution.

Abstract

383 Background: In recent years adjuvant therapy (AT) for pancreatic cancer has evolved. Improved overall survival (OS) was demonstrated first in 2017 with gemcitabine and capecitabine (GemCap), and then further improved in 2018 with FOLFIRINOX compared to gemcitabine (gem) alone. Given these options, we retrospectively reviewed the patterns of AT allocation in the province of British Columbia (BC) during these periods of adoption of newer AT regimens. Methods: Patients (pts) treated at BC Cancer centers between January 2017 to June 2018 (the GemCap era), and July 2018 to July 2019 (the FOLFIRINOX era), who had undergone curative intent resection and received at least one cycle of AT were included for chart review. Patient and disease characteristics, treatment details, and stated rationale for choice of AT regimen were collected. Analyses were performed with one-way ANOVA for comparison of means between regimens, and Chi-squared or Fisher Exact tests to determine correlation between clinicopathologic factors and likelihood of undergoing a given AT regimen. Results: 122 pts were identified: 67 treated in the GemCap era (gem: 25, 37%, and GemCap: 42, 63%) and 55 treated in the FOLFIRINOX era (gem: 18, 33%, GemCap: 18, 33%, FOLFIRINOX: 19, 34%). Examined variables included age, gender, ECOG, T and N stage, margins, lymphovascular invasion and post-operative CA19-9. In the GemCap era, use of GemCap vs Gem was associated with younger average age (p = 0.001) and positive lymph node status (91% vs. 60%, p = 0.005). In the FOLFIRINOX era, use of gem AT was associated with a delayed time from surgery to consultation. (p = 0.036) AT assignment was not influenced by high volume vs low volume centre in the GemCap era; however, pts were more likely to receive GemCap in low-volume centres during the mFOLFIRINOX era (p = 0.045). The most common stated reasons for choice of a less intense AT regimen were pt comorbidities or functional status (GemCap era: 24% and FOLFIRINOX era: 31%). Conclusions: Despite improvements in survival with newer AT regimens, the majority of pts in our real-world setting were assigned a less intense AT regimen. Within the limits of a small sample size, significant pt or disease factors predictive of AT assignment were not identified aside from age and lymph node positivity in the GemCap era, and time from surgery to consultation in the FOLFIRINOX era. Efforts to improve adoption of newer AT regimens and optimize pt eligibility for FOLFIRINOX are warranted.