Efficacy of second-line treatment and importance of comorbidity scores and clinical parameters affecting prognosis in elderly patients with non-small cell lung cancer without epidermal growth factor receptor mutations.

The present study investigated the importance of comorbidity scores and clinical parameters in elderly patients with non-small cell lung cancer (NSCLC) not harboring epidermal growth factor receptor (EGFR) mutations who received second-line chemotherapy. The present study also compared the efficacy of tyrosine kinase inhibitor and cytotoxic chemotherapy as second-line treatment in elderly patients. The present study retrospectively reviewed the treatment of elderly patients with NSCLC (≥70 years old) who received second-line chemotherapy at Korea University Guro Hospital. Patients who had an EGFR mutation were excluded from the analysis. Between 2005 and 2013, 126 patients were included in the present study. The median progression-free survival (PFS) and overall survival (OS) for all patients who received second-line treatment were 2.47 months [95% confidence interval (CI), 2.08-2.86] and 8.63 months (95% CI, 5.99-11.28), respectively. A total of 52 patients (41.3%) were treated with tyrosine kinase inhibitor (TKI) and 74 (58.7%) were treated with chemotherapy. No difference was observed in the median PFS and OS between the TKI and chemotherapy groups (P=0.287 for PFS and P=0.374 for OS). The Charlson comorbidity index was not associated with survival, whereas a simplified comorbidity score and clinical factors, including poor performance status, short PFS of first-line chemotherapy, presence of brain metastasis and low serum albumin and sodium levels were significant prognostic factors in these elderly patients. Second-line chemotherapy was not beneficial to patients who had at least 3 of these factors and a median OS of 1.73 months, whereas patients who had less than 2 of these factors had a median OS of 11.50 months. For elderly lung cancer patients without EGFR mutations, clinical parameters were the most important factors affecting survival, rather than the types of drugs.