Prognostic implications of body composition changes in patients with non-metastatic pancreatic adenocarcinoma treated with mFOLFIRINOX.

Background: Computed tomography (CT) enables non-invasive, comprehensive assessment of body composition in patients with cancer. In pancreatic ductal adenocarcinoma (PDAC), where weight and body composition change during treatment are common, serial CT evaluation may provide prognostic insights. Methods: Patients with non-metastatic PDAC treated with first-line mFOLFIRINOX between January 2017 and December 2020 were retrospectively included. Body composition at the L3 vertebral level was quantified at baseline and 12-week CT scans using a previously validated AI tool (AID-U™; iAID Inc.). Skeletal muscle area, muscle attenuation, and body fat area were used to derive skeletal muscle index (SMI), normal-to-total attenuation muscle area ratio (NAMA/TAMA), visceral fat area (VFA), and subcutaneous fat index (SFI), representing muscle mass, muscle quality, and visceral and subcutaneous adiposity, respectively. Results: A total of 733 patients with baseline CT scans were included in the analyses, and 595 patients with paired CT scans at baseline and at 12 weeks after initiation of mFOLFIRINOX were included in longitudinal change analyses. Subsequent curative resection was performed in 269 (34.6%) patients. Overall, SMI, VFA, SFI, and body mass index (BMI) declined significantly over the first 12 weeks, particularly among patients who did not undergo curative resection and in those with progressive disease. In resected patients, baseline visceral obesity was associated with worse OS. In non-resected patients, larger 12-week decreases in SMI, SFI, and BMI were associated with poorer OS. Conclusion: Serial CT-based assessment of body composition during chemotherapy may provide valuable prognostic information in non-metastatic PDAC.