Radiation Plus Anti-PD-1 Therapy for NSCLC Brain Metastases: A Retrospective Study

Guixiang Liao; Yuting Qian; Sumbal Arooj; Zhihong Zhao; Maosheng Yan; Zihuang Li; Hongli Yang; Tao Zheng; Gang Li; Xianming Li; Muhammad Khan

doi:10.3389/fonc.2021.742971

Radiation Plus Anti-PD-1 Therapy for NSCLC Brain Metastases: A Retrospective Study

Front Oncol. 2021 Oct 21:11:742971. doi: 10.3389/fonc.2021.742971. eCollection 2021.

Authors

Guixiang Liao¹, Yuting Qian², Sumbal Arooj^{1

3}, Zhihong Zhao⁴, Maosheng Yan¹, Zihuang Li¹, Hongli Yang¹, Tao Zheng¹, Gang Li⁵, Xianming Li¹, Muhammad Khan^{1

6}

Affiliations

¹ Department of Oncology, Shenzhen People's Hospital, The First Affiliated Hospital Of Southern University Of Science And Technology, Shenzhen, China.
² Department of Radiation Oncology, Shenzhen People's Hospital, The Second College of Jinan University, Shenzhen, China.
³ Department of Biochemistry and Molecular Biology, University of Sialkot, Sialkot, Pakistan.
⁴ Department of Nephrology, Shenzhen People's Hospital, Second Clinical Medicine Centre, Jinan University, Shenzhen, China.
⁵ Department of Chemoradiation Oncology, The First Affiliated Hospital Of Wenzhou Medical University, Wenzhou, China.
⁶ Department of Oncology, The First Affiliated Hospital of Anhui Medical University, Hefei, China.

Abstract

Background: Radiation therapy (RT) is the mainstay of brain metastases (BMs), and anti-PD-1 blockade has led to intracranial responses in non-small cell lung carcinoma (NSCLC) patients with BMs.

Objective: This study aimed to evaluate the efficacy and safety of adding anti-PD-1 blockade to RT in the management of NSCLC patients with BM in terms of survival outcome.

Materials and methods: We retrospectively reviewed 70 NSCLC patients with BMs who were treated with whole brain radiation therapy (WBRT) between January 2016 and January 2021. Of the 70 patients, 29 additionally received anti-PD-1 therapy within 30 days of WBRT initiation. Baseline characteristics of the patients and efficacy outcomes such as progression-free survival (PFS) and overall survival (OS) were statistically compared using SPSS v26. Results were obtained using the Chi-square test/Fisher exact test, t-test, Kaplan-Meier, and Cox regression survival analyses.

Results: The median survival for the entire cohort was 24 months (95% CI, 19.5-28.5). The median survival times for WBRT alone and WBRT plus anti-PD-1 therapy cohorts were 20 months (95% CI, 11.6-28.3) and 27 months (95% CI, 19.5-28.5), respectively (p=0.035). There was no statistical difference in PFS for the treatment cohorts (median PFS for WBRT alone: 7 months vs. 12 months for WBRT plus anti-PD-1, p=0.247). In EGFR wild-type subgroup (n=31), both PFS (p=0.037) and OS (p=0.012) were significantly improved. Only the treatment group (WBRT plus anti-PD-1) was a significant predictor of OS on univariate and multivariate analyses (p=0.040). There were no significant differences in adverse events among the treatment groups.

Conclusions: NSCLC patients with BM receiving additional anti-PD-1 therapy may derive better OS than WBRT alone without any increase in adverse events. Prospective well-designed studies are warranted to validate and elucidate the additive effects of the two modalities in this group of patients.

Keywords: anti-PD-1 immunotherapy; brain metastasis (BM); immune checkpoint blockade (ICB); immunotherapy (IT); non-small cell lung cancer (NSCLC); whole brain radiation therapy (WBRT).