High-Risk Factors for Recurrence of Stage I Lung Adenocarcinoma: Follow-up Data From JCOG0201

The aim of this study was to identify patients with pathological stage I lung adenocarcinoma at high risk of recurrence.

We retrieved data from 536 patients with pathological stage I lung adenocarcinoma who underwent lobectomy and were enrolled in a prospective multiinstitutional study (the JCOG0201 study). Invasive component size, excluding lepidic component, was used as the tumor size. Recurrence-free survival (RFS) was estimated by the Kaplan-Meier method, and a multivariable Cox proportional hazards model identified independent prognostic factors associated with worse RFS.

The all-patient 10-year RFS was 83.9% (median follow-up 10.2 years). Multivariable Cox analysis revealed that age greater than 65 years (hazard ratio [HR], 2.60; 95% confidence interval (CI), 1.66-4.07), invasive component size greater than 2 cm (HR, 2.70; 95% CI, 1.40-5.23), visceral pleural invasion (HR, 2.17; 95% CI, 1.23-3.81), and vascular invasion (HR, 2.59; 95% CI, 1.47-4.55) were potential independent prognostic factors for RFS. When patients were divided into a high-risk group for recurrence (invasive component size >2 cm or positive for visceral pleural invasion or for vascular invasion; n = 124) and a low-risk group (invasive component size ≤2 cm and negative for visceral pleural invasion and vascular invasion; n = 408), there was a significant difference in RFS between the high-risk and low-risk groups (high-risk group: HR, 3.61; 95% CI, 2.35-5.55).

Pathological stage I lung adenocarcinoma patients with an invasive component size greater than 2 cm, visceral pleural invasion, or vascular invasion were at high risk for recurrence.