RESUMO
BACKGROUND: Baseline patient and disease characteristics are investigated in non-small-cell lung cancer (NSCLC) in an effort to predict response to treatment and optimize patients' outcomes. Histology has recently been identified in multiple NSCLC phase III trials as a predictive factor for survival in patients receiving pemetrexed regimens. METHODS: Cox-adjusted models were used to further analyze a randomized phase III study in 1725 chemonaive patients with stage IIIB or IV NSCLC and Eastern Cooperative Oncology Group performance status (PS) of zero or one who received cisplatin plus pemetrexed (CP; C, 75 mg/m(2) and P, 500 mg/m(2)) or cisplatin plus gemcitabine (CG; C, 75 mg/m(2) and G, 1250 mg/m(2)) every 21 days. RESULTS: Histology was confirmed to be predictive of CP efficacy and may also be prognostic. Gender, ethnicity, disease stage, smoking status, and PS were not predictive in either treatment arm but were shown to be prognostic in the nonsquamous population, consistent with the results in the overall NSCLC population. CONCLUSIONS: NSCLC histology significantly predicts efficacy outcomes for patients receiving pemetrexed. Several other factors are prognostic for the overall study population as well as a subset of patients with advanced nonsquamous NSCLC.