Significance of pretreatment comorbidities in elderly patients with advanced non-small-cell lung cancer treated with chemotherapy or epidermal growth factor receptor-tyrosine kinase inhibitor.

A standard, valid assay of comorbidities for elderly patients with advanced non-small-cell lung cancer (NSCLC) who have received antitumor therapy is needed to provide useful prognostic information. The aim of this study was to analyze prognostic factors and validate classic Charlson comorbidity index (CCI) and comorbidity scores in elderly patients with advanced NSCLC treated with chemotherapy or epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs). A retrospective analysis was conducted on 162 patients with advanced NSCLC over 70 years old at diagnosis, who were treated with cytotoxic chemotherapy or with EGFR-TKIs between April 2003 and April 2009 at Kyoto University Hospital. Collected data included clinical assessments, treatments, toxicities, and outcomes. Survival was estimated using the Kaplan-Meier method. Prognostic factors were evaluated with log-rank and Cox regression tests. Based on multivariate analysis, unspecified NSCLC histology [Hazard ratio (HR), 1.631; 95% Confidence interval (CI), 1.184-2.263; P = 0.0016], more than 3 comorbidities (HR, 1.317; 95% CI, 1.020-2.675; P = 0.0350), and a CCI of more than 3 (HR, 1.321; 95% CI, 1.031-1.664; P = 0.0285) were significant independent negative prognostic factors for survival. Our results indicate that CCI and the number of comorbidities are independent predictors of survival in elderly patients undergoing systemic chemotherapy including EGFR-TKIs for advanced NSCLC. These factors should be taken into consideration in the pretreatment assessment as important factors predicting survival outcome.

Good clinical response to gefitinib in a non-small cell lung cancer patient harboring a rare somatic epidermal growth factor gene point mutation; codon 768 AGC > ATC in exon 20 (S768I).

Recently, two small-molecule kinase inhibitors targeting epidermal growth factor receptor have proven effective in the treatment of non-small cell lung cancer. There are specific activating mutations within the tyrosine kinase domain of epidermal growth factor receptor related to the sensitivity of tyrosine kinase inhibitors. However, it is unknown whether rare mutations in the N-lobe (exons 18-20) and the C-lobe (exon 21) of the epidermal growth factor receptor kinase domain other than L858R in exon 21 and the in-frame deletion in exon 19 may predict the effectiveness of epidermal growth factor receptor-tyrosine kinase inhibitors. We reported a case of non-small cell lung cancer harboring a rare epidermal growth factor somatic mutation, codon 768 AGC > ATC in exon 20 (S768I), who showed a good clinical response to gefitinib. Therefore, we may suggest that this rare mutation (S768I in exon 20) may not be an insensitive epidermal growth factor receptor somatic mutation in vivo.