Adjuvant Chemotherapy Decisions in the Treatment of Lung Cancer Considering Nonrelapse Mortality: A Multicenter Study

Background: Adjuvant chemotherapy (Adj) reduces recurrence and improves long-term survival in patients with surgically resected lung cancer. However, it has minimal impact on patients who die without relapsing. To optimize Adj indications, we aimed to identify factors associated with nonrelapse mortality (NRM).

Patients and methods: This multicenter, retrospective, observational study enrolled patients with surgically resected with stages II-III non-small cell lung cancer. Multivariable Cox regression analysis was performed to identify the factors associated with NRM and early-NRM within 2 years of surgery and to stratify the enrolled patients. Adj administration rates and postoperative overall and recurrence-free survival rates were compared. Multivariable competing regression analysis with NRM as a competing risk was used to assess the cumulative incidence of lung cancer-associated death and recurrence.

Results: Through a scoring system assigning 1 point to each extracted factor (old age, male sex, poor performance status, nonadenocarcinoma, and occurrence of major complications), the 1,244 included patients were stratified into 3 groups based on scores of 0-5: A (0-1 points; n = 613), B (2-3 points; n = 549), and C (4-5 points; n = 62) with 53%, 26%, and 11% Adj administration, respectively. Although group A showed the highest overall and recurrence-free survival rates, competing regression analysis showed no significant differences in cumulative lung cancer-associated death and recurrence incidence between the groups.

Conclusion: Better prognosis in group A was attributed to lower NRM and higher Adj administration rates. While proactive Adj may benefit group A, careful evaluation is warranted for group C to optimize Adj indication.