Supplementary Material for: Primary Tumor Resection Is Associated with a Better Outcome among Advanced EGFR-Mutant Lung Adenocarcinoma Patients Receiving EGFR-TKI Treatment

Objectives: The characteristics and efficacy of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) in advanced EGFR-mutant lung adenocarcinoma patients with primary tumor resection (PTR) is not yet clear. Methods: We enrolled advanced EGFR-mutant lung adenocarcinoma patients with EGFR-TKI as first-line therapy to access the impact of PTR on the outcomes. Results: A total of 466 patients were enrolled with 76 patients (16.3%) undergoing PTR; 59 patients recurred after curative surgery, while 17 patients underwent surgery as diagnostic purposes. PTR patients displayed a better performance status, a lower metastatic burden, and much less measurable diseases (30.3 vs. 97.4%, p p p = 0.004). Survival advantage was still observed while comparing PTR patients with the better performance and lower metastatic burden subgroup found within the non-resection group. Moreover, the progression-free survival and overall survival of 11 patients who were found having pleural metastases during surgery and underwent PTR plus pleural biopsy, were also longer than those with pure N0--1/M1a-malignant pleural effusion disease in the non-resection group (n = 19) (p p = 0.002, respectively). Conclusion: PTR was associated with significantly better outcomes in advanced lung adenocarcinoma patients treated with EGFR-TKI. Further studies are needed to evaluate the biological role of PTR among these patients.