Recurrence Risk-Scoring Model for Stage I Adenocarcinoma of the Lung
Hee Chul Yang1, Hyeong Ryul Kim2, Sanghoon Jheon3
1Department of Thoracic and Cardiovascular Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seoul, South Korea.
Purpose:
The aim of this retrospective, multicenter study was to develop a recurrence risk-scoring model in patients with curatively resected stage I lung adenocarcinoma (ADC).
Methods:
Clinicopathologic and outcome data for a development cohort of 1,700 patients with pathologic stage I ADC from four institutions resected between January 2000 and December 2009 were evaluated. A phantom study was performed for correction of inter-institutional differences in positron emission tomography-standardized uptake value (PET-SUV). A nomogram for recurrence prediction was developed using Cox proportional hazards regression. This model was validated in a cohort of 460 patients in two other hospitals. The recurrence rate was 21.0 % for the development cohort and 22.1 % for the validation cohort.
Results:
In multivariable analysis, three independent predictors for recurrence were identified: pathologic tumor size (hazard ratio [HR] 1.03, 95 % CI 1.017-1.048; p < 0.001), corrected PET-SUV (HR 1.08, 95 % CI 1.051-1.105; p < 0.001), and lymphovascular invasion (HR 1.65, 95 % CI 1.17-2.33; p = 0.004). The nomogram was made based on these factors and a calculated risk score was accorded to each patient. Kaplan-Meier analysis of the development cohort showed a 5-year recurrence-free survival (RFS) of 83 % (95 % CI 0.80-0.86) in low-risk patients and 59 % (95 % CI 0.54-0.66) in high-risk patients with the highest 30 percentile scores. The concordance index was 0.632 by external validation.
Conclusions:
This recurrence risk-scoring model can be used to predict the RFS for pathologic stage I ADC patients using the above three easily measurable factors. High-risk patients need close follow-up and can be candidates for adjuvant chemotherapy.
