Objective:

To review recent advances in treatment strategies and candidate biomarkers for extensive-stage small cell lung cancer (ES-SCLC), with a focus on reviewing existing evidence regarding the role of thoracic radiotherapy (TRT) in the era of immunotherapy.

Key Findings:

• Chemotherapy combined with immunotherapy has become the new standard for first-line treatment of ES-SCLC, improving overall survival and progression-free survival.
• The absolute survival benefit from immunotherapy remains limited, with only a 3-month extension in median overall survival compared to chemotherapy alone.
• Thoracic radiotherapy has shown significant survival benefits and reduced intrathoracic recurrence in ES-SCLC patients responding to chemotherapy.
• The combination of TRT with chemoimmunotherapy is a promising area of exploration, though optimal dosing and timing are still under investigation.

Interpretation:

The integration of thoracic radiotherapy with immunotherapy and chemotherapy may enhance treatment outcomes for ES-SCLC, but further research is needed to identify the best patient candidates and treatment protocols, particularly regarding optimal dosing and timing of TRT.

Limitations:

• The predictive value of biomarkers for the efficacy of combined therapies remains unclear.
• Current studies have not fully incorporated TRT into treatment regimens in the context of immunotherapy, limiting the understanding of its potential benefits.

Conclusion:

Combining thoracic radiotherapy with immunotherapy and chemotherapy may offer improved survival outcomes for ES-SCLC patients, highlighting the need for personalized treatment approaches based on biomarker classification and ongoing research.