Importance: Associations of body mass index (BMI) with survival in pancreatic ductal adenocarcinoma (PDA) have substantial variability in literature, potentially due to heterogeneous patient populations and retrospective analyses. Additionally, BMI may inadequately describe body composition (ie, morphomics; including subcutaneous and visceral fats, muscle, and fascia), which might have independent biological roles and associations with survival.
Objective: To study the associations of BMI and morphomics with survival and metabolomics in metastatic PDA.
Design, setting, and participants: This cohort study prospectively collected patient data, imaging, and serum on the phase 3 trial (Avenger500), which investigated the efficacy and safety of 5-fluorouracil, leucovorin, oxaliplatin, and irinotecan (FOLFIRINOX) versus modified FOLFIRINOX plus devimistat. The randomized trial accrued 528 patients with chemotherapy-naive, metastatic PDA from Europe, Israel, Korea, and the US between 2018 and 2020. In the present study, per-protocol patients with L1 to L4, T10 to T12 vertebral levels were evaluated. Data analysis occurred from January 2023 to April 2024.
Exposure: Patient data were collected by clinical staff. Morphomics were analyzed from baseline imaging. Metabolites were extracted from baseline serum.
Main outcome and measures: A multifaceted statistical approach evaluated associations of BMI and morphomics with progression-free survival (PFS) and overall survival (OS). Associations of morphomics with metabolites were also studied.
Results: Of the 528 initial patients, 476 (median [IQR] age, 63 [56-68] years; 280 male [58.8%]; median [IQR] BMI, 25.0 [22.1-25.9]) were evaluable for the present study. BMI (obese [≥30] compared with normal [18.5-24.9]) was not associated with OS (hazard ratio [HR], 0.90; 95% CI, 0.67-1.22; P for trend = .33). More subcutaneous fat was associated with longer OS (HR, 0.62; 95% CI, 0.41-0.94; P for trend = .02). Higher visceral fat density was associated with shorter PFS (HR, 1.74; 95% CI, 1.23-2.48; P for trend = .002) and OS (HR, 1.50; 95% CI, 1.12-2.00; P for trend = .008). A higher muscle-to-fascia ratio was associated with longer PFS (HR, 0.58; 95% CI, 0.40-0.84; P for trend = .005) and OS (HR, 0.56; 95% CI, 0.41-0.75; P for trend = 1.7 × 10-4). Subcutaneous fat was positively associated with long-chain fatty acid metabolism including pristanic acid, decanoylcarnitine, decenoylcarnitine, and octanoylcarnitine. Muscle-to-fascia was positively associated with metabolites including acetylcarnosine (β = 0.34; 95% CI, 0.21-0.47; P = 1.27 × 10-6).
Conclusions and relevance: In cohort study of patients with metastatic PDA, BMI was not associated with survival. Higher visceral fat density, subcutaneous fat area, and muscle-to-fascia ratio were associated with survival independent of BMI. The latter 2 were associated with higher levels of animal product metabolism. These findings could represent novel focuses for prognostication and intervention to improve survival of patients with PDA.