The VEGF-driven tumour pathway has been demonstrated to represent a novel therapeutic target for an innovative class of antineoplastic agents. Among these antiangiogenetic-targeted treatment modalities the anti-VEGF monoclonal antibody bevacizumab has become a new standard of care for first-line treatment of metastatic colorectal cancer. The biological link between hypoxia, LDH levels and the tumour-driven angiogenesis pathway through the abnormal activation of the hypoxia Inducible factor 1 α (HIF1-α) is well established. HIF1-α is a key transcription factor that up-regulates a series of genes involved in glycolytic metabolism, angiogenesis, cell survival and erythropoiesis Accordingly to this biological assumption Azuma et al (Azuma et al 2007) demonstrated that high LDH serum levels were associated with tumour over-expression of VEGFA and VEGFR-1. As a clinical consequence it has been speculated that LDH levels may represent an indirect indicator of activated tumour angiogenesis and ultimately of worse prognosis We previously analysed the role of LDH pre-treatment serum levels in colorectal cancer patients receiving first-line bevacizumab in metastatic colorectal cancer treated with first-line bevacizumab were 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