Relationship between Lactate Dehydrogenase and survival in patients with non-small cell lung cancer receiving immunotherapy.

Objective: The expression level of programmed death ligand 1 (PD-L1) is the only approved biomarker for predicting response to immunotherapy, yet its efficacy is not always consistent. Lactate dehydrogenase (LDH) has been associated with tumor aggressiveness and poorer prognosis across various cancer types and may serve as a useful biomarker for monitoring treatment response. The objective of this study is to analyze the relationship between LDH levels prior to the start of treatment with immune checkpoint inhibitors (ICIs) and clinical outcomes in patients with non-small cell lung cancer (NSCLC).

Method: A retrospective study was conducted including patients diagnosed with NSCLC who were treated with at least three cycles of immunotherapy. Data on demographics, clinical and pathological characteristics, treatment received, pre-treatment LDH levels, and clinical outcomes such as treatment response and overall survival (OS) were analyzed.

Results: A total of 181 patients diagnosed with NSCLC were included. Elevated pre-treatment LDH levels (more than 244 U/l) were associated with significantly reduced OS. The median survival was 548 days in patients with LDH less than 244 U/l, compared to 332 days in those with LDH more than 244 U/l (p = 0.037). Among men, OS was greater in the LDH less than 244 U/l group (623 days) versus 332 days in the LDH more than 244 U/l group (p = 0.043). In patients with metastatic disease, OS was higher in those with LDH less than 244 U/l (474 days) compared to 249 days in those with LDH more than 244 U/l (p = 0.023). In patients receiving both immunotherapy and chemotherapy, OS was greater in those with LDH less than 244 U/l (623 days) compared to 281 days in the LDH more than 244 U/l group (p = 0.042).

Conclusions: High levels of LDH prior to the start of treatment with ICIs are associated with lower treatment efficacy and a worse prognosis of the disease, especially in male, metastatic patients with a PD-L1 expression level less than 1%.