Antiprogrammed death ligand 1 therapy failed to reduce the risk of developing brain metastases in patients with extensive-stage small cell lung cancer: A retrospective analysis

Addition of thoracic radiotherapy to a PD-L1 inhibitor plus chemotherapy regimen delays brain metastasis onset in extensive-stage small cell lung cancer patients without baseline brain metastasis

BACKGROUND

With the application of immune checkpoint inhibitors (ICIs) and the discovery of the synergistic effect of radiotherapy and immunotherapy, the intracranial benefit of thoracic radiotherapy (TRT) is receiving signiffcant clinical attention. The purpose of this study was to analyze the cranial benefits of ICIs and TRT in patients with extensive-stage small cell lung cancer (ES-SCLC) without baseline brain metastases (BMs).

MATERIALS AND METHODS

From August 2019 to August 2022, data from patients diagnosed with ES-SCLC without baseline BMs were retroactively recorded. The Kaplan‒Meier method was used to calculate overall survival (OS), progression-free survival (PFS), and brain metastasis-free survival (BMFS), and the differences between the treatment groups were compared with the log-rank test. Risk factors associated with OS were analyzed via the Cox regression model.

RESULTS

A total of 216 patients were included, with a median follow-up of 24.73 months. Among these patients, 137 (63.4%) received first-line ICIs combined with chemotherapy (ChT), including 32 patients treated with anti-programmed death 1 antibody (αPD-1) and 105 patients treated with anti-programmed death-ligand 1 antibody (αPD-L1), and 79 patients (36.6%) received first-line ChT alone. Compared with the ChT-alone group, the ICI + ChT group demonstrated significantly improved PFS (8.07 vs. 6.87 months; p < 0.001) and OS (19.83 vs. 13.80 months; p = 0.001). The addition of ICIs to the ChT regimen did not significantly delay the onset of BMs compared to that with ChT alone (16.93 vs. 12.67 months; p = 0.379). Notably, the addition of TRT to the αPD-L1 + ChT regimen significantly prolonged BMFS compared to that without TRT (20.27 vs. 8.80 months; p = 0.045).

CONCLUSION

In patients with ES-SCLC without baseline BMs, first-line chemoimmunotherapy significantly improves PFS and OS. However, it does not delay intracranial metastasis. The addition of TRT to αPD-L1 + ChT therapy significant delays the development of BMs.

CLINICAL TRIAL NUMBER

Not applicable.

Metastatic brain tumors: from development to cutting-edge treatment

Metastatic brain tumors, also called brain metastasis (BM), represent a challenging complication of advanced tumors. Tumors that commonly metastasize to the brain include lung cancer and breast cancer. In recent years, the prognosis for BM patients has improved, and significant advancements have been made in both clinical and preclinical research. This review focuses on BM originating from lung cancer and breast cancer. We briefly overview the history and epidemiology of BM, as well as the current diagnostic and treatment paradigms. Additionally, we summarize multiomics evidence on the mechanisms of tumor occurrence and development in the era of artificial intelligence and discuss the role of the tumor microenvironment. Preclinically, we introduce the establishment of BM models, detailed molecular mechanisms, and cutting-edge treatment methods. BM is primarily treated with a comprehensive approach, including local treatments such as surgery and radiotherapy. For lung cancer, targeted therapy and immunotherapy have shown efficacy, while in breast cancer, monoclonal antibodies, tyrosine kinase inhibitors, and antibody-drug conjugates are effective in BM. Multiomics approaches assist in clinical diagnosis and treatment, revealing the complex mechanisms of BM. Moreover, preclinical agents often need to cross the blood-brain barrier to achieve high intracranial concentrations, including small-molecule inhibitors, nanoparticles, and peptide drugs. Addressing BM is imperative.

The Optimal Radiotherapy Strategy for Patients With Small Cell Lung Cancer and Brain Metastasis: A Retrospective Analysis

BACKGROUND

Extensive-stage small cell lung cancer (ES-SCLC) is a notoriously aggressive malignancy frequently associated with brain metastases (BMs), presenting substantial therapeutic challenges. This study delves into the effectiveness of immunotherapy combined with diverse radiotherapy, especially the influence of brain radiotherapy (BRT) on survival outcomes in the immunotherapy era.

METHODS

ES-SCLC patients treated at Xiangya Hospital and Xiangya Boai Hospital from February 2020 to June 2024 were retrospectively included. The study focused on patients receiving immune checkpoint inhibitors (ICIs). Metrics included overall survival (OS) and progression-free survival (PFS), employing univariate and multivariate Cox regression models for statistical analysis.

RESULTS

A total of 393 patients with ES-SCLC who received ICIs were included in the study. Within the entire cohort, the presence of baseline BMs did not statistically affect OS or PFS. However, thoracic radiotherapy (TRT) was identified as a favorable prognostic factor for both OS and PFS. BRT demonstrated a beneficial effect on OS across both the general cohort and the baseline_BMs subgroup. In patients from the baseline_BMs subgroup who had previously undergone TRT, ICIs plus BRT did not significantly improve OS compared to ICIs alone. Conversely, for patients who had not received prior TRT, adding BRT to ICIs significantly enhanced OS. Among the patients who underwent BRT, 71 received whole brain radiotherapy (WBRT) while 19 opted for stereotactic radiosurgery (SRS). No significant differences in OS and PFS were observed between the SRS and WBRT modalities. The sequence of ICIs relative to BRT was found to influence PFS adversely. Administering BRT before ICIs (RT-ICI) was associated with worse PFS compared to administering ICIs followed by BRT (ICI-RT). Additionally, no significant differences in OS and PFS were noted among the three subgroups defined by varying intervals between ICIs and BRT. For patients without baseline BMs, TRT and prophylactic cranial irradiation were associated with delayed onset of brain metastases.

CONCLUSIONS

Our study underscores the importance of optimizing treatment strategies and considering the timing and integration of radiotherapy and immunotherapy to improve outcomes for patients with ES-SCLC, particularly those at risk of or presenting with BMs.

Cumulative incidence and risk factors of brain metastases in metastatic non-small cell lung cancer without baseline brain metastasis: Pooled analysis of individualized patient data from IMpower130, IMpower131, and IMpower150

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.

Treatment patterns and clinical outcomes in 157 patients with extensive-stage small cell lung cancer: real-world evidence from a single-center retrospective study

Background

Immune checkpoint inhibitors (ICIs) have changed the therapeutic options for extensive-stage small-cell lung cancer (ES-SCLC). In this real-world study, we analyzed the treatment patterns in patients with ES-SCLC and evaluated the efficacy of chemotherapy combined with immunotherapy as first-line therapy.

Methods

A retrospective analysis was performed on patients with ES-SCLC who received treatment at China-Japan Friendship Hospital (Beijing, China) between August 1, 2020, and April 30, 2023. The treatment patterns appeared in the form of Sunburst Chart and Sankey diagram. The survival analyses were conducted by Kaplan-Meier curves.

Results

A total of 157 patients with ES-SCLC were retrospectively included. According to first-line therapy, patients were divided into the chemotherapy (CT) group (n=82) and chemo-immunotherapy (CIT) group (n=75). The median treatment lines were 2[1, 2] and cycles were 8[5, 12], respectively. 82 patients received the second line of therapy, followed by 37 for the third, 15 for the fourth, 11 for the fifth, and 5 for the sixth. Overall, the treatment patterns involved 11 options including 12 chemotherapy regimens, 11 ICIs, and 4 targeted agents. The second-line treatment pattern had the most options (9) and regimens (43). In the first 3 lines, chemotherapy was the largest proportion of treatment options. The addition of ICIs prolonged progression-free survival from 6.77 (95% confidence interval [CI], 6.00-7.87) to 7.33 (95% CI, 6.03-9.80) months (hazard ratio [HR]=0.67, 95% CI, 0.47-0.95; P=0.025), overall survival from 12.97 (10.90-23.3) to 14.33 (12.67-NA) months without statistically significant difference (HR=0.86, 95% CI, 0.55-1.34; P=0.505).

Conclusion

The treatment options of patients with ES-SCLC are more diversified. Combination therapy is the current trend, where chemotherapy is the cornerstone. Meanwhile, ICIs participate in almost all lines of treatment. However, the clinical efficacy remains barely satisfactory. We are urgently expecting more breakthrough therapies except immunology will be applied in the clinic.