Pre-treatment lactate dehydrogenase levels as predictor of efficacy of first-line bevacizumab-based therapy in metastatic colorectal cancer patients.

Lactate dehydrogenase (LDH) represents a predictive factor in colorectal cancer patients treated with the angiogenesis inhibitor PTK/ZK. We explored the role of pre-treatment LDH serum levels in colorectal cancer patients receiving first-line bevacizumab.Metastatic colorectal cancer treated with first-line bevacizumab was eligible. A control group including all consecutive patients treated with chemotherapy alone was also considered. Pre-treatment LDH serum levels were collected for all cases.Median progression-free survival (PFS) in the control group for patients with high and low LDH levels was 4.2 and 8 months, respectively (P=0.0003). Median overall survival (OS) was 19.6 and 34.9 months for patients with high and low LDH levels, respectively (P=0.0014). In the bevacizumab group, partial responses were seen in 14 (58\%) high-LDH and 8 (14\%) low-LDH patients (P=0.0243), respectively, median PFS was 7.3 and 8.5 months, respectively (P=0.2), and median OS was 22 and 26.6 months, respectively (P=0.7).High LDH levels correlated with worse prognosis. Bevacizumab seemed capable of improving clinical outcome in this specific group of patients who usually present with an adverse natural history. The improved response rate also suggests a role for LDH as a predictive marker.