Objective:

To evaluate the prognostic significance of serum LDH in patients with extensive-stage small-cell lung cancer (ES-SCLC) undergoing combined chemo-immunotherapy and consolidative thoracic radiotherapy, highlighting its relevance in existing literature.

Key Findings:

• Serum LDH was independently associated with poorer overall survival (HR 1.006 per 1 U increase, 95% CI 1.003–1.009, p < 0.001).
• Patients with elevated LDH levels (>250 U/L) had significantly reduced overall survival compared to those with lower levels (p=0.0012).
• The prognostic nomogram demonstrated moderate discriminative ability with AUCs of 0.731 at 12 months and 0.694 at 24 months, indicating its potential clinical utility.

Interpretation:

Serum LDH serves as a significant prognostic marker for overall survival in ES-SCLC patients receiving modern treatment regimens, aiding in risk stratification and personalized management, with implications for clinical practice.

Limitations:

• Retrospective design may introduce selection bias, potentially affecting the reliability of the findings.
• Single-center study limits generalizability of findings, suggesting the need for multi-center validation.

Conclusion:

The study confirms the independent prognostic value of serum LDH in ES-SCLC and presents a nomogram for predicting survival, which may enhance personalized treatment strategies in clinical practice.