Objective: This study investigated the factors predicting recurrence and death in patients with resected stage-I non-small-cell lung cancers according to the 7th edition of tumor, node, metastasis (TNM) classification for lung cancer.
Methods: All patients undergoing surgical resection for pathological stage-I non-small-cell lung cancers at Taipei Veterans General Hospital between 1980 and 2000 were retrospectively reviewed. Those undergoing sublobar resection were excluded. The factors predicting overall survival (OS), overall recurrence, local recurrence, and distant metastasis were investigated.
Results: A total of 756 patients were eligible. The 5-year OS rate and probability of freedom from recurrence were 57.3% and 70.2%, respectively. The 2-year local-recurrence-free and distant-metastasis-free rates were 90.7% and 82.1%, respectively. In multivariable analysis, the new T descriptor (T1a, T1b, and T2a) was the common factor that significantly affected OS (p = 0.003), overall recurrence (p = 0.004), and distant metastasis (p < 0.001). Smoking index more than 20, and number of mediastinal lymph nodes dissected/sampled of 15 or fewer were common factors that significantly predicted worse OS (p < 0.001, p < 0.001, respectively), lower probability of freedom from overall recurrence (p = 0.025, p = 0.009, respectively), and higher risk of local recurrence (p < 0.001, p = 0.030, respectively). Non-squamous-cell histology predicted higher risk of distant metastasis (p = 0.006).
Conclusions: Risks of death and recurrence increase as the T descriptor upgrades in the new TNM system. The combination of risk factors can be used to identify high-risk subgroups of local recurrence and distant metastasis.