PGF and cancer: Both VEGF and placental growth factor (PlGF) plasma levels were found significantly increased after BV treatment in rectal cancer patients enroled in small phase I and II trials that investigated the safety and efficacy of BV (Willett et al, 2005, 2009), whereas Gordon et al (2001) described a reduction of free serum VEGF in cancer patients treated with escalating doses of BV, when compared with basal concentrations.