Primary Tumor Resection for Stage IV Non-small-cell Lung Cancer Without Progression After First-Line Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitor Treatment: A Retrospective Case-Control Study

Background In studies of stage IV epidermal growth factor receptor (EGFR)-mutant nonsmall-cell lung cancer (NSCLC), <10% of patients underwent surgery; thus, the effect of surgery in these patients remains unclear. We investigated whether primary lung tumor resection could improve the survival of patients with stage IV EGFR-mutant NSCLC without progression after first-line EGFR-tyrosine kinase inhibitor (EGFR-TKI) treatment. Methods This retrospective case-control study included patients treated with first-line EGFR-TKIs without progression on follow-up imaging. Patients in the surgery group (n = 56) underwent primary tumor resection, followed by TKI maintenance therapy. Patients in the control group (n = 224; matched for age, metastatic status, and Eastern Cooperative Oncology Group performance status) received only TKI maintenance therapy. Local ablative therapy for distant metastasis was allowed in both groups. The primary endpoint was progression-free survival. The secondary endpoints were overall survival, failure patterns, and complications/adverse events. Results The median time from TKI treatment to surgery was 5.1 months. For the surgery and control groups, the median follow-up periods were 34.0 and 38.5 months, respectively, with a median (95% confidence interval) progression-free survival of 29.6 (18.9-40.3) and 13.0 (11.8-14.2) months, respectively (P < 0.001). Progression occurred in 29/56 (51.8%) and 207/224 (92.4%) patients, respectively. The median overall survival in the surgery group was not reached. The rate of surgical complications of grade >= 2 was 12.5%; complications were treated conservatively. Conclusions Primary tumor resection is feasible for patients with EGFR-mutant nonprogressed NSCLC during first-line EGFR-TKI treatment and may improve survival better than maintenance EGFR-TKI therapy alone.