Prognostic factors of EGFR-mutated metastatic adenocarcinoma of lung.

Purpose: The first-line treatment of metastatic lung adenocarcinoma with epidermal growth factor receptor (EGFR) mutation is tyrosine kinase inhibitor (TKI). This study aimed to evaluate potential factors affecting the progression-free survival under TKI treatment.

Methods: Forty one patients with EGFR-mutated metastatic lung adenocarcinoma under first-line TKI treatment were retrospectively evaluated. Ten factors potentially influencing the progression-free survival were studied: patients' age, gender, smoking history, number of comorbidities, performance status, tumor mutation site, maximum of standardized uptake value (SUV) of primary tumor in FDG PET/CT, serum CEA level, number of metastatic organs and presence of pleural/pericardial effusion. Mantel-Cox tests and waterfall plots were performed for statistical analyses.

Results: Statistical evaluation demonstrated that primary SUV, serum CEA level, gender and smoking history were important prognostic factors, with corresponding p values of 0.001, 0.023, 0.034 and 0.041 respectively in Mantel-Cox analyses.

Conclusion: Low primary SUV, low serum CEA level, female and never smoker were four prognostic factors suggestive of good response to TKI in mutated EGFR metastatic lung adenocarcinoma. SUV is probably the most important among the four factors.