Patients with lung cancer often present with recurrence, even after resection. The identification of risk factors for recurrence after resection is useful.Methods:
Among 1,338 patients with lung cancer who underwent a complete resection, 277 developed recurrences post surgery. Data regarding the TNM factors, histologic subtype, and presence/absence of vessel invasion were analyzed retrospectively using the survival tree method to identify groups with a high risk of recurrence after resection.Results:
The results revealed that the T factor, the N factor, and lymphatic (ly) and blood (v) vessel invasion were related to the risk of recurrence, and six combinations of these factors were identified using the survival tree method: group A: v = 0, T ≤ 1b, ly = 0; group B: v = 0, T ≤ 1b, ly ≥ 1; group C: v = 0, T ≥ 2a; group D: v ≥ 1, N ≤ 1, T ≤ 2b; group E: v ≥ 1, N ≤ 1, T ≥ 3; and group F: v ≥ 1, N ≥ 2. The six groups were then further classified into three groups: a low-risk group (group A), a moderate-risk group (groups B, C, and D), and a high-risk group (groups E and F). The 5-year recurrence-free survival rate was approximately 98% for the low-risk group, 75% for the moderate-risk group, and 30% for the high-risk group.Conclusions:
Combining the T, N, v, and ly factors allowed the precise identification of a group with a high risk of recurrence after resection.