Outcomes and predictive factors for pathological node-positive in radiographically pure-solid, small-sized lung adenocarcinoma.

ABSTRACT

OBJECTIVES: The indication of limited resection for radiographically pure-solid, small-sized lung adenocarcinoma is controversial. This study aimed to reveal the long-term outcome of standard surgical treatment and determine the predictive factors for pathological lymph node metastasis in optimal candidates undergoing limited surgical resection for pure-solid, small-sized lung adenocarcinoma. METHODS: The medical records of 107 consecutive patients were retrospectively reviewed at our hospital between December 2002 and December 2013. Inclusion criteria were histopathological diagnosis of lung adenocarcinoma, radiographically pure-solid tumor, ≤ 2 cm tumor size measured using thin-section computed tomography, clinical N0M0, patients who underwent lobectomy with systematic or lobe-specific lymph node dissection, and R0 resection. Overall and disease-free survival curves were calculated using the Kaplan-Meier method. Clinicopathological factors predicting pathological node-positive metastasis were identified by univariate and multivariate analysis. RESULTS: The 5-year overall and disease-free survival rates were 91.4% and 87.3%, respectively. Multivariate analysis demonstrated maximum standardized uptake value > 5 as the independent predictor of pathological node-positive metastasis (odds ratio 3.81; 95% confidence interval 1.25-12.3; p = 0.02). In all patients, the pathological node-positive rate was 16.7%; in patients who had a maximum standardized uptake value of ≤ 5, the rate was 7.9%. CONCLUSION: The long-term outcome of standard surgical treatment was favorable. Maximum standardized uptake value was a significant predictor of pathological node-positive metastasis; however, diagnostic accuracy was not favorable. Therefore, the selection of optimal candidates is difficult, and limited surgical resection may not be applicable in pure-solid, small-sized lung adenocarcinoma.