Resection of Primary Lung Tumors in Patients with Stage IV EGFR-Mutant Lung Adenocarcinoma before Progression under First-Line TKI Treatment and Its Impact on Prognosis.

INTRODUCTION: Systemic therapy is generally recommended for patients with stage IV lung cancer over primary tumor resection (PTR). Although some randomized trials have shown a survival benefit of PTR in advanced ovarian cancer, breast cancer, and colorectal cancer with peritoneal carcinomatosis, the efficacy of PTR in stage IV lung cancer remains uncertain. This study aimed to determine whether PTR affects the survival of patients with stage IV epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma (ADC).

PATIENTS AND METHODS: We utilized the cancer registry database of Kaohsiung Chang Gung Memorial Hospital, Taiwan. Between 1 January 2018 and 21 December 2022, 652 patients were diagnosed with stage IV EGFR-mutant lung ADC. After exclusion, 400 patients were included, 33 of whom underwent PTR. After propensity score matching, 26 patients who underwent PTR and 78 who did not were selected for the analysis.

RESULTS: Patients who received PTR exhibited better progression-free survival (PFS) (not reached (NR) versus 17.1 months; p = 0.001) and overall survival (OS) (NR versus 38.2 months; p = 0.011) than patients who did not. In the multivariate analysis, lower clinical M stage and PTR were significantly associated with improved PFS and OS. Subgroup analysis of independent factors regarding both PFS and OS that predicted improvement following PTR included male sex, age ≥ 60, never smoked, performance status (PS) = 1, clinical T stage 3-4, clinical N stage 0-2, and clinical M stage 1a.

CONCLUSIONS: In patients with stage IV EGFR-mutant lung ADC and good PS, PTR before progression under first-line TKI treatment may improve survival.