Erlotinib for advanced non-small-cell lung cancer in the elderly: an analysis of the National Cancer Institute of Canada Clinical Trials Group Study BR.21.

Abstract

National Cancer Institute of Canada Clinical Trials Group Study BR.21 established erlotinib as a standard of care in patients with non-small-cell lung cancer (NSCLC) after failure of first- or second-line chemotherapy. The current study analyzes the influence of age on outcomes in BR.21. BR.21 was a double-blind phase III trial that randomly assigned 731 patients to erlotinib 150 mg daily or placebo. End points included progression-free survival and overall survival (OS), response, quality of life (QOL), drug exposure, and toxicity, which are analyzed in this retrospective study by the following two age groups: >or= 70 years (elderly) or less than 70 years (young). There were 163 elderly patients (112 on erlotinib, 51 on placebo) and 568 young patients (376 on erlotinib, 192 on placebo). There was no significant difference between age groups randomly assigned to erlotinib or placebo in progression-free survival (elderly: 3.0 v 2.1 months; hazard ratio [HR] = 0.63; 95% CI, 0.44 to 0.90; P = .009; young: 2.1 v 1.8 months; HR = 0.64; 95% CI, 0.53 to 0.76; P < .0001; interaction, P = .77) or OS (elderly: 7.6 v 5.0 months; HR = 0.92; 95% CI, 0.64 to 1.34; P = .67; young: 6.4 v 4.7 months; HR = 0.73; 95% CI, 0.61 to 0.89; P = .0014; interaction, P = .31). Response rates were similar between age groups. Elderly patients, compared with young patients, had significantly more overall and severe (grade 3 and 4) toxicity (35% v 18%; P < .001), were more likely to discontinue treatment as a result of treatment-related toxicity (12% v 3%; P < .0001), and had lower relative dose-intensity (64% v 82% received > 90% planned dose; P < .001). Elderly patients treated with erlotinib gain similar survival and QOL benefits as younger patients but experience greater toxicity.