Efficacy of Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitors in Metastatic Non-Small Cell Lung Cancer Patients with Poor Performance Status and Epidermal Growth Factor Receptor Mutations: Findings from the Japanese Lung Cancer Registry Database

Background In advanced non-small cell lung cancer (NSCLC) patients harboring epidermal growth factor receptor (EGFR) mutations, those with impaired performance status (PS) treated with EGFR-tyrosine kinase inhibitors (TKIs) have demonstrated comparable activities to good-PS patients. Due to the limited sample size and inclusion of older adult patients with good PS, these findings may not accurately depict the efficacy of EGFR-TKI in poor-PS patients. We investigated the benefit of EGFR-TKIs in this population and identified relevant prognostic factors. Patients and Methods This nationwide prospective registry study included 9872 patients with local or advanced NSCLC. Outcomes were compared between poor- and good-PS patients treated with EGFR-mutated lung cancer therapies. Results Of 9872 NSCLC patients, 1965 (19.9%) had EGFR mutations, with 1846 (93.9%) presenting common EGFR mutations. Poor PS (PS score ≥ 3) was noted in 171 patients (8.7%) and identified as an independent prognostic factor; those with poor PS had a significantly lower 1-year survival rate. The median overall survival (OS) for EGFR-TKI-treated good-PS patients was 31.5 (95% confidence interval, 29.6-33.4) months. Among poor-PS patients with EGFR mutations, 135 (78.9%) of whom were treated with EGFR-TKI had an OS of 15.5 (12.7-18.3) months, while those receiving only supportive care had an OS of 2.5 (1.4-3.6) months (P < .001). Hypoalbuminemia (< 3.5 g/dL), liver metastasis, and uncommon EGFR mutations were associated with poor prognosis. Conclusion Poor PS at diagnosis was rare and associated with limited EGFR-TKI efficacy and a dismal prognosis. Liver metastasis and hypoalbuminemia may reduce EGFR-TKI efficacy in these patients.