Prognostic implication of body composition changes in patients with borderline resectable/locally advanced pancreatic adenocarcinoma (PDAC) treated with mFOLFIRINOX.

783 Background: Although cachexia is a known prognostic factor in patients with advanced cancer, individual body composition changes during chemotherapy and their association with survival in PDAC warrant further investigation. We aimed to analyze the prognostic implication of comprehensive body composition, including areas and attenuation of muscle mass, body fat area and its distribution, and body mass index (BMI) during mFOLFIRINOX in patients with PDAC. Methods: Patients with borderline resectable or locally advanced PDAC, who were not able to undergo curative surgery and received first-line mFOLFIRINOX between January 2017 and December 2020 from Asan Medical Center, Seoul, Korea, were included in this retrospective study if they had paired CT scans of the abdomen at baseline and after 12 weeks of mFOLFIRINOX. Body composition was measured using artificial intelligence software (AID-UTM, iAID Inc.) from the CT images, and their association with overall survival (OS) were analyzed. Results: A total of 377 patients were included. Median age was 63 (range, 56–69) and 214 patients (56.8%) were males and 163 patients (43.2%) were females. During the first 12 weeks, significant changes in the body composition occurred as follows (median changes and interquartile range): skeletal muscle area, -5.8% [-11.1%–0.6%]; normal attenuation muscle area/total attenuation muscle area, -2.8% [-8.7%–3.2%]; visceral fat area (VFA), -6.1% [-23.7%–18.6%]; skeletal fat area (SFA), -12.2% [-27.8%–77.1%]; and BMI, -2.2% [-6.8%–1.5%]. Furthermore, changes in the VFA and BMI was associated with tumor response (Kruskal-Wallis test, p = 0.012 for VFA; p = 0.054 for BMI). There was no significant relationship between body composition abnormalities including sarcopenia, myosteatosis, or obesity at baseline and OS. However, patients who experienced the greatest decrease in SFA and BMI after 12 weeks of mFOLFIRINOX had poorer OS (tertile 1 [greatest decrease] vs 3 [smallest decrease]: HR 0.67 [95% CI, 0.52–0.87] for SFA, p = 0.003; 0.68 [95% CI, 0.49–0.83] for BMI, p = 0.001). Conclusions: In patients with borderline resectable/locally advanced PDAC, body composition significantly changes during the first 12 weeks. Decrease in the body fat and BMI from baseline were associated with poorer tumor response and OS.