Comorbidity, age and overall survival in patients with advanced pancreatic cancer - results from NCIC CTG PA.3: a phase III trial of gemcitabine plus erlotinib or placebo

Abstract

Background: The effect of comorbidity, age and performance status (PS) on treatment of advanced pancreatic cancer is poorly understood. We examined these factors as predictors of outcome in advanced pancreatic cancer patients treated with gemcitabine +/- erlotinib.

Patients and methods: Comorbidity was evaluated by two physicians using the Charlson Comorbidity Index (CCI) and correlated with clinical outcome data from the NCIC Clinical Trials Group (NCIC CTG) PA.3 clinical trial.

Results: Five hundred and sixty-nine patients were included; 47% were aged ≥ 65 years old, 36% had comorbidity (CCI>0). In multivariate analysis, neither age (p=0.22) nor comorbidity (p=0.21) was associated with overall survival. The baseline presence of better PS and lower pain intensity scores was associated with better overall survival (p < 0.0001 and p=0.01, respectively). An improvement in survival with the addition of erlotinib therapy was seen in patients age < 65 (adjusted hazard ratio (HR) 0.73, p=0.01) or in the presence of comorbidity (adjusted HR 0.72, p=0.03). However, neither age nor CCI score was predictive of erlotinib benefit after test for interaction. Patients treated with gemcitabine plus erlotinib who were ≥ 65 years of age or those with comorbidity had a higher rate of infections ≥ grade 3.

Conclusion: Low baseline pain intensity and better PS were associated with improved overall survival, while age and comorbidity were not independent prognostic factors for patients treated with gemcitabine-based therapy.