ABSTRACT
BACKGROUND: This was a post hoc analysis of patients with non-squamous histology from a phase III maintenance pemetrexed study in advanced non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: The six symptom items' [average symptom burden index (ASBI)] mean at baseline was calculated using the lung cancer symptom scale (LCSS). Low and high symptom burden (LSB, ASBI < 25; HSB, ASBI ≥ 25) and performance status (PS: 0, 1) subgroups were analyzed for treatment effect on progression-free survival (PFS) and overall survival (OS) using the Cox proportional hazard models adjusted for demographic/clinical factors. RESULTS: Significantly longer PFS and OS for pemetrexed versus placebo occurred in LSB patients [PFS: median 5.1 versus 2.4 months, hazard ratio (HR) 0.49, P < 0.0001; OS: median 17.5 versus 11.0 months, HR 0.63, P = 0.0012] and PS 0 patients (PFS: median 5.5 versus 1.7 months, HR 0.36, P < 0.0001; OS: median 17.7 versus 10.3 months, HR 0.54, P = 0.0019). Significantly longer PFS, but not OS, occurred in HSB patients (median 3.7 versus 2.8 months, HR 0.50, P = 0.0033) and PS 1 patients (median 4.4 versus 2.8 months, HR 0.60, P = 0.0002). CONCLUSIONS: ASBI and PS are associated with survival for non-squamous NSCLC patients, suggesting that maintenance pemetrexed is useful for LSB or PS 0 patients following induction.
