Adipose tissue and survival among patients with advanced biliary tract cancer.

BACKGROUND: Adiposity may promote the progression of different types of cancer. The prognostic significance of visceral and subcutaneous adipose tissue has not been thoroughly investigated in patients with advanced biliary tract cancer. METHODS: Using a single-institutional series of 386 patients with unresectable or recurrent biliary tract cancer, we measured visceral and subcutaneous adipose tissue areas (both normalized by body height) based on abdominal computed tomography images. Using the Cox regression model with adjustment for potential confounders, we calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for progression-free survival (PFS) and overall survival (OS) according to adipose tissue areas. RESULTS: Neither visceral nor subcutaneous adipose tissue area was associated with PFS or OS (Ptrend > 0.02 at the α level of 0.005 accounting for multiple comparisons). The multivariable HRs for PFS comparing the highest to lowest quartiles were 1.01 (95% CI, 0.71-1.45) and 0.95 (95% CI, 0.67-1.36) for visceral and subcutaneous adipose tissue, respectively. The corresponding HRs for OS were 0.84 (95% CI, 0.61-1.16) and 0.71 (95% CI, 0.52-0.96), respectively. Null survival associations were also observed for total adipose tissue area and visceral-to-subcutaneous adipose tissue area ratio (Ptrend > 0.06). CONCLUSIONS: The adipose tissue area was not significantly associated with survival outcomes of patients with advanced biliary tract cancer. Our data suggest a minimal role of adiposity status in determining tumor progression and patient survival in this population.