2024 World Conference on Lung Cancer (WCLC) - ePosters-EP.09A.05 Consolidative Thoracic Radiotherapy Induced Lymphopenia in Metastatic NSCLC Is Predicted by EDIC and Associated with Poor Clinical Outcomes

EP.09A.05 Consolidative Thoracic Radiotherapy Induced Lymphopenia in Metastatic NSCLC Is Predicted by EDIC and Associated with Poor Clinical Outcomes

Back to course

Pdf Summary

The study led by Drs. Kyra McComas and Ryan Whitaker at the Vanderbilt-Ingram Cancer Center investigates the impact of consolidative thoracic radiotherapy on lymphopenia in patients with metastatic non-small cell lung cancer (NSCLC). It aims to understand the complications that arise from combining thoracic radiotherapy with maintenance immune checkpoint inhibitors (ICIs) following upfront chemoimmunotherapy. The Effective Dose to Immune Cells (EDIC) was used as a predictive measure for lymphopenia, which affects the immune system's efficacy.<br /><br />The study includes a retrospective review of six patients with stage IV NSCLC, who received consolidative thoracic radiotherapy after demonstrating at least stable disease under prior chemoimmunotherapy. The median follow-up for these patients was 313 days, with lymphocyte counts monitored before, during, and after radiation therapy. Results indicated significant lymphopenia, observing grade 3-4 lymphopenia in four patients—three of whom experienced disease progression within 100 days. In contrast, two patients displayed grade 1 lymphopenia, one showing no progression during the study period.<br /><br />The findings suggest that high-grade lymphopenia, predicted by EDIC and observed after consolidative radiotherapy, correlates with poorer clinical outcomes. Notably, patients with lower EDIC readings exhibited lower grades of lymphopenia, inferring that the extent of radiation might play a critical role in immune system impairment. The research concludes that thoracic radiotherapy in conjunction with ICIs contributes to poorer prognoses due to its detrimental effect on systemic immune function, as evidenced by the failure of ph2 NRG LU-002.<br /><br />Future directions include exploring shorter, more targeted radiation courses with reduced total doses, and revisiting fractionation schedules to ameliorate lymphopenia risks, thus potentially improving clinical outcomes in metastatic NSCLC patients undergoing consolidative radiation therapies.

Asset Subtitle

Ryan Whitaker

Meta Tag

Speaker Ryan Whitaker

Topic Metastatic Non-small Cell Lung Cancer – Local Therapies

Keywords

consolidative thoracic radiotherapy

lymphopenia

metastatic non-small cell lung cancer

immune checkpoint inhibitors

Effective Dose to Immune Cells

chemoimmunotherapy

clinical outcomes

radiation therapy

immune system impairment

fractionation schedules