1012 - The Cost Effectiveness of Neoadjuvant FOLFIRINOX vs. Gemcitabine Based Chemoradiotherapy (CRT) for Resectable or Borderline-Resectable Pancreatic Ductal Adenocarcinoma

Purpose/Objective(s): The recently published PREOPANC-2 trial showed no significant survival improvement in treating patients with resectable or borderline-resectable pancreatic ductal adenocarcinoma (PDAC) with neoadjuvant FOLFIRINOX (FFX) vs. gemcitabine-based chemoradiotherapy (CRT), with both arms surviving approximately 21-22 months. Though the treatments appear clinically equivalent, it is unclear whether differences arise when considering toxicity and cost of treatment. Therefore, we created a decision tree to compare the risks and benefits of treating PDAC with FFX vs. CRT.

Materials/Methods: We constructed a decision tree using utilities and costs per month from the literature, and probabilities directly from the PREOPANC-2 trial. Overall survival (OS) was defined as the time between randomization and death from any cause (including treatment); impact on quality of life was calculated in quality-adjusted life months (QALMs). We assumed OS as 30 months if there was resectable disease both FFX and CRT groups followed by surgery, 8 months OS for FFX or CRT without surgery (i.e. due to disease progression or unresectable disease), and 3-6 months OS for treatment-refractory PDAC/resistance to treatment. The length of FFX treatment was 3 months, 6 months for CRT. Adverse events from treatment were considered to last 3 months. Probability of metastatic disease, unresectable disease, death from treatment, and adverse events (diarrhea and neutropenia) were derived from PREOPANC-2.

Utilities from the literature include 0.8 for progression-free survival (PFS), 0.73 for survival with disease progression (metastatic or unresectable disease) before surgery, and 0.58 for survival with progression after surgery. We assumed the same utility for metastatic and unresectable disease. We used a utility of 0.526 for serious adverse events.

Costs of FFX, CRT, and surgery were assumed to be $101,518, $59,900, and $99,157. Costs of adverse events of diarrhea and neutropenia were estimated to be $7,868 and $6,324.

Results: In our base case (assuming equal toxicity of FFX and CRT), we found that FFX treatment resulted in more QALMs (18.98 vs. 18.02) compared to CRT, but with an additional cost of $36,697.02. However, even though CRT treatment length was longer than FFX, if CRT toxicity is improved relative to FOFIRINOX to a utility of 0.7, the CRT strategy becomes preferred and dominant (19.22 QALM, -$36,697.02).

Conclusion: Treating PDAC with FFX vs. CRT results in minimal differences in QALMs that are dependent on the toxicity of treatment. If considered equitoxic, though FFX results in slightly improved QALMs, the cost exceeds most definitions of societal willingness-to-pay ($458,712 per additional QALY). If the toxicity of CRT is considered significantly improved compared to FFX, CRT becomes the dominant strategy.