Image-guided radiofrequency ablation for treatment of stage I non-small cell lung cancer in 111 high-risk patients: Analysis of prognostic variables.

[BACKGROUND] Surgical resection is the standard treatment for stage I non-small cell lung cancer (NSCLC). Radiofrequency ablation (RFA) is an option in high-risk patients who cannot undergo surgical resection of stage I NSCLC, but prognostic factors and long-term oncologic results have not been fully evaluated. We evaluated outcomes after image-guided RFA and factors associated with survival in high-risk patients with stage I NSCLC.

[METHODS] We evaluated the outcomes of image-guided-RFA performed by thoracic surgeons for biopsy-proven stage I NSCLC in high-risk patients over a 17-year period. The primary endpoint evaluated was overall survival (OS), studied using Kaplan-Meier analysis. Covariates associated with OS were analyzed with univariate proportional hazards regression and multivariate Cox regression.

[RESULTS] One hundred and eleven patients (median age, 74 years) underwent image-guided RFA. After a median follow-up of 30 months, estimated OS was 86% at 1 year (95% confidence interval [CI] 80%-93%) and 54% at 3 years (95% CI, 46%-64%). During follow-up, local progression in the treated lesion, as per imaging criteria, occurred in 44 patients (40%) among whom 14 had histologically proven recurrence (13%). Covariates associated with improved OS in multivariate analysis included size <2 cm (P = .043) and adenocarcinoma histology (P = .013).

[CONCLUSIONS] Although surgical resection remains the standard, image-guided RFA is effective for high-risk patients with stage I NSCLC who are not surgical candidates. Analysis of covariates associated with survival identified lesion size and histology as important prognostic factors. Prospective studies of RFA are needed to further define patient selection in this high-risk group.