De-escalation of Adjuvant EGFR-TKI in Stage IB EGFR-Mutated Non-small-cell Lung Cancer: A Real-World Study.

BACKGROUND: The clinical benefit of adjuvant epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) in stage IB non-small-cell lung cancer (NSCLC) remains controversial. This study evaluated the impact of adjuvant EGFR-TKIs on long-term survival in a real-world cohort of patients with stage IB NSCLC. METHODS: A total of 340 patients with resected stage IB EGFR-mutated NSCLC were included in this study and divided into two groups (TKI+ group: with adjuvant EGFR-TKI; TKI- group: without adjuvant EGFR-TKI). Kaplan-Meier and Cox regression analyses were used to compare overall survival, disease-free survival, and recurrence-free survival between groups. Propensity score matching was performed to minimize selection bias. RESULTS: Among 340 included patients, 46.8% (159/340) received an EGFR-TKI. Adjuvant EGFR-TKIs significantly improved 5-year disease-free survival (TKI- group: 76.1% vs. TKI+ group: 82.8%, P = 0.005) and 5-year recurrence-free survival (TKI- group: 80.2% vs. TKI+ group: 86.7%, P = 0.013) in patients with stage IB NSCLC. However, no significant difference was observed in 5-year overall survival (TKI- group: 90.4% vs. TKI+ group: 90.2%, P = 0.315). Subgroup analysis showed that, in patients with tumors ≤ 3 cm, those with partial-solid tumors, and those without high-risk factors, adjuvant EGFR-TKIs had no impact on long-term survival (all P > 0.05). Furthermore, no significant difference in long-term survival was observed between first-generation and third-generation EGFR-TKIs. CONCLUSION: Despite the limitations of a retrospective design, our findings suggest that adjuvant EGFR-TKIs might be omitted in patients with stage IB NSCLC with tumors ≤ 3 cm, those with partial-solid tumors, or those without high-risk factors.