Adjuvant epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) for the treatment of people with resected stage I to III non-small-cell lung cancer and EGFR mutation.

BACKGROUND

Postoperative adjuvant epidermal growth factor receptor (EGFR) inhibitor osimertinib is the standard care for stage IB-IIIB non-small-cell lung cancer (NSCLC) with EGFR exon 19 deletions or exon 21 L858R mutation, following complete tumour resection, with or without prior platinum-based adjuvant chemotherapy. However, the role of EGFR tyrosine kinase inhibitors (TKIs) in this setting is debated, particularly concerning long-term curative effects versus recurrence delay. Uncertainties persist around treatment duration, harms, and effectiveness across disease stages, prior chemotherapy, or EGFR-sensitising mutation types.

OBJECTIVES

To assess the effectiveness and harms of adjuvant EGFR tyrosine kinase inhibitors (TKIs) in people with resected stage I to III non-small-cell lung cancer (NSCLC) harbouring an activating EGFR mutation.

SEARCH METHODS

We searched major databases (CENTRAL, MEDLINE, Embase) to 9 December 2024, along with conference proceedings (from 2019) and clinical trial registries.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) reporting benefits or harms of adjuvant EGFR TKIs in adults with resected stage I-III NSCLC. Trials compared EGFR TKIs with platinum-based chemotherapy, placebo/best supportive care (BSC), or second-and/or third-generation EGFR TKIs versus first- and/or second-generation EGFR TKIs. Participants were adults with histologically confirmed stage I-III NSCLC.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed search results, resolving disagreements with a fourth author. Primary outcomes were overall survival (OS), disease-free survival (DFS), and adverse events (AEs); secondary outcomes included health-related quality of life (HRQoL), relapse risk during drug-off time, and brain relapse risk. We conducted meta-analyses using random-effects and fixed-effect models with hazard ratios (HRs) or risk ratios (RRs) and 95% confidence intervals (CIs). We assessed heterogeneity with the I² statistic.

MAIN RESULTS

We included nine RCTs involving 2603 participants, and identified six ongoing trials. Five trials compared EGFR TKIs with placebo/BSC, and four compared them with chemotherapy. We found no trials comparing second-and/or third-generation to first- and/or second-generation EGFR TKIs. Six trials had low selection bias risk; most had unclear or high risk for detection or performance bias; and four were high risk for other biases. The certainty of the evidence (GRADE) ranged from moderate to very low, depending on the outcome. First-, second-, and/or third-generation EGFR TKIs versus placebo/BSC EGFR TKIs probably improve overall survival compared to placebo/BSC (HR 0.54, 95% CI 0.40 to 0.73; 3 studies, 864 participants; moderate-certainty evidence). TKIs may improve disease-free survival compared to placebo/BSC, but the evidence is very uncertain (HR 0.34, 95% CI 0.28 to 0.41; 5 studies, 1153 participants). We are uncertain if there is a difference between groups in serious adverse events (≥ grade 3) as the evidence is very uncertain, with wide confidence intervals spanning both potential harm and no effect (RR 2.52, 95% CI 0.44 to 14.37; 4 studies, 1134 participants). Mild-to-moderate adverse events (grades 1 and 2) may be more frequent with EGFR TKIs compared to placebo/BSC, but the evidence is very uncertain (RR 1.57, 95% CI 1.08 to 2.29; 4 studies, 1134 participants). One study assessed HRQoL, with no clinically meaningful decline compared to placebo/BSC (592 participants; moderate-certainty evidence). First-, second-, and/or third-generation EGFR TKIs versus chemotherapy Overall survival was similar between EGFR TKIs and chemotherapy (HR 0.79, 95% CI 0.52 to 1.18; 4 studies, 878 participants; moderate-certainty evidence). TKIs may have improved disease-free survival compared to chemotherapy (HR 0.54, 95% CI 0.35 to 0.83; 4 studies, 878 participants; low-certainty evidence). TKIs may have reduced serious adverse events (≥ grade 3) compared to chemotherapy (RR 0.31, 95% CI 0.18 to 0.52; 4 studies, 811 participants; low-certainty evidence). TKIs may have increased mild-to-moderate adverse events (grades 1 and 2) (RR 2.13, 95% CI 1.20 to 3.78; 4 studies, 811 participants; low-certainty evidence). Two studies assessed HRQoL, showing no clear difference compared to chemotherapy, as assessed with the Functional Assessment of Cancer Therapy-Lung instrument (2 studies, 399 participants) and the Lung Cancer Symptom Scale (2 studies, 400 participants), both with moderate-certainty evidence.

AUTHORS' CONCLUSIONS: Adjuvant EGFR TKIs may improve disease-free survival compared to both placebo/BSC and chemotherapy. There is moderate-certainty evidence that EGFR TKIs increase overall survival compared to placebo/BSC. However, they likely result in little to no difference in overall survival compared to chemotherapy. We could not rule out a potential survival benefit of adjuvant chemotherapy in people with EGFR-mutant NSCLC. Approximately 50% of participants experienced relapse or death within one year of stopping TKI therapy, indicating that the disease-free survival benefit may wane after withdrawal. This raises the possibility that prolonged adjuvant TKI therapy could be associated with improved long-term outcomes, although further research is needed to clarify this.