AI Summary
This study examined the cumulative incidence and risk factors of brain metastases in metastatic non-small cell lung cancer (NSCLC) without baseline brain metastases. Data from three trials using atezolizumab plus chemotherapy were pooled and analyzed. The results showed that there was no significant difference in the cumulative incidence of brain metastases between patients treated with atezolizumab plus chemotherapy and those treated with chemotherapy alone. However, the use of bevacizumab and histology of nonsquamous NSCLC were found to be independently associated with the risk of developing brain metastases. These findings suggest that adding atezolizumab in the first-line treatment may not reduce the risk of brain metastases, but the use of bevacizumab could potentially lower this risk.
Abstract
Background
The objective of this study was to explore the abilities of atezolizumab plus chemotherapy in preventing brain metastases (BMs) among metastatic non–small cell lung cancer (NSCLC) without initial BMs, as well as the risk factors of BMs.
Methods
Individual patient data from three trials involving first-line atezolizumab for metastatic NSCLC (IMpower130, IMpower131, and IMpower150) were pooled. Among patients without baseline BMs and without epidermal growth factor receptor (EGFR) and/or anaplastic lymphoma kinase (ALK) mutations, those receiving atezolizumab + chemotherapy ± bevacizumab were classified as the atezolizumab plus chemotherapy group and those receiving placebo + chemotherapy ± bevacizumab were classified as the chemotherapy group. The cumulative incidences of BM (CI-BMs) between the two groups were compared. Other factors associated with the CI-BM were analyzed by Cox regression analyses.
Results
With a median follow-up of 17.6 months (range, 0.03–33.64 months), 74 (3.1%) of the 2380 enrolled patients developed BMs, including 50 (3.1%) and 24 (3.0%) in the atezolizumab plus chemotherapy group (n = 1589) and the chemotherapy group (n = 791), respectively. The CI-BMs at 6, 12, and 24 months were 1.7%, 2.8%, and 3.3%, respectively. After taking competing risk events into account, there was no significant difference in the CI-BMs between the two groups (p = .888). Nevertheless, the use of bevacizumab and the histology of nonsquamous NSCLC were found to be independently associated with the risk of BMs.
Conclusions
In patients with metastatic EGFR/ALK wild-type NSCLC without baseline BMs, adding atezolizumab in the first-line treatment might not reduce the CI-BM. However, the administration of bevacizumab may reduce the risk of BMs.