Intrathoracic Progression Is Still the Most Dominant Failure Pattern after First-Line Chemo-immunotherapy in...

Area of Science:

• Oncology
• Radiation Oncology
• Medical Oncology

Background:

• Extensive-stage small-cell lung cancer (ES-SCLC) presents significant treatment challenges.
• Immunotherapy has emerged as a key treatment modality, altering failure patterns.
• Understanding the role of thoracic radiotherapy (TRT) alongside novel therapies is crucial.

Purpose of the Study:

• To compare failure patterns in ES-SCLC before and after immunotherapy introduction.
• To evaluate the specific role of TRT in the context of modern ES-SCLC treatment paradigms.
• To assess the efficacy of TRT in improving locoregional control.

Main Methods:

• Retrospective review of 294 ES-SCLC patients.
• Comparison of treatment groups: chemotherapy alone, chemotherapy + TRT, and chemotherapy + immune checkpoint inhibitors (ICI).
• Propensity-score matching (PSM) applied for robust treatment group comparisons.

Main Results:

• TRT group showed significantly lower intrathoracic progression at first relapse compared to chemotherapy alone and ICI groups.
• Subgroup analysis indicated TRT benefits in intrathoracic progression-free survival (PFS) for specific patient subsets.
• Post-PSM analysis confirmed superior intrathoracic PFS with TRT versus chemotherapy alone and ICI, though overall PFS and survival benefits were not significant compared to ICI.

Conclusions:

• Intrathoracic progression remains a dominant failure pattern in ES-SCLC, even with immunotherapy.
• Consolidative TRT is a valuable strategy for enhancing locoregional control in the era of chemoimmunotherapy for ES-SCLC.
• TRT can be considered for patients requiring improved intrathoracic disease management.