Elevated levels of pre-treatment lactate dehydrogenase are an unfavorable predictor factor in patients with EML4-ALK rearrangement non-small cell lung cancer treated with crizotinib.

An elevated pre-treatment serum LDH level (>250 U/L) was significantly associated with shorter PFS in patients with EML4-ALK rearrangement NSCLC. Post-treatment elevated serum LDH level was not significantly associated with PFS, which related to adverse events including muscle damage and anemia.