SESSION TYPE: Thoracic Surgery II
PRESENTED ON: Tuesday, October 23, 2012 at 04:30 PM - 05:45 PM
PURPOSE: Controversy remains over the routine use of invasive (such as mediastinoscopy) or expensive (such as positron emission tomography) diagnostic procedures in stage T1 non-small cell lung cancer (NSCLC) without lymph node enlargement on computed tomography (CT) as the risk of mediastinal lymph node metastasis is comparatively low in such patients. We aimed to develop a prediction model for N2 disease in CT defined T1N0 NSCLC to aid in the decision-making process.
METHODS: We reviewed the records of 530 CT defined T1N0 NSCLC patients who underwent surgical resection with systematic lymph node dissection. Correlations between N2 involvement and clinicopathological parameters were assessed using univariate analysis and binary logistic regression analysis. A prediction model was built on the basis of logistic regression analysis, and was internally validated using bootstrapping.
RESULTS: Incidence of N2 disease was 16.8%. Four independent predictors were identified in multivariate logistic regression analysis and were included in the prediction model: age at diagnosis (OR = 0.974; 95% CI: 0.952-0.997), tumor size (OR = 2.769; 95% CI: 1.818-4.217), central tumor location (OR = 3.204; 95% CI: 1.512-6.790), and invasive adenocarcinoma histology (OR = 3.537; 95% CI: 1.740-7.191). Hosmer-Lemeshow test of goodness-of-fit was not significant (P = 0.784), suggesting a high concordance between predicted and observed probabilities. The area under the ROC curve, which measures the model’s accuracy, was reasonable (0.726, 95% CI: 0.669-0.784). Internal validation by bootstrapping showed the bias corrected area under the ROC curve was 0.717, and the extent of “over-optimism” is minimal (0.009, 1.2%), indicating that this prediction model holds for future patients.
CONCLUSIONS: We developed a four-predictor model that can estimate the probability of N2 disease in CT defined T1N0 NSCLC. This prediction model can help to determine the cost-effective utilization of mediastinal staging procedures.
CLINICAL IMPLICATIONS: The predicted likelihood of N2 nodal involvement has implications for the cost-effective utilization of diagnostic procedures, such as mediastinoscopy and PET, in staging mediastinal lymph nodes in CT defined T1N0 NSCLC.
DISCLOSURE: The following authors have nothing to disclose: Yang Zhang, Yihua Sun, Jiaqing Xiang, Yawei Zhang, Hong Hu, Haiquan Chen
No Product/Research Disclosure InformationDepartment of Thoracic Surgery, Fudan University Shanghai Cancer Center, Shanghai, China