VEGFA and esophageal cancer: Researchers suggested that the postoperative VEGF increase might be the angiogenetic response to tissue repair.26 Compared with preop levels, VEGF levels were found to be low at postop 4 and 24 hours in the 30 patients who had mastectomy operation under general anasthesia using nitrous oxide but no statistically significant difference was found.18 A significant decrease was seen in VEGF levels in patients with oesophagus cancer on day one following surgical trauma.