Task: Question Answering
Input (English): Context: Vascular endothelial growth factor (VEGF) is a hypoxia-induced endothelial cell-specific mitogen, which is angiogenic in vivo and up-regulated in several malignancies. VEGF can be used as a prognostic marker, but the effect of surgical trauma on serum VEGF (S-VEGF) concentrations is unknown and might reduce the value of VEGF as a serum marker.', 'We monitored S-VEGF levels by enzyme-linked immunosorbent assay in patients undergoing surgery.', 'Eighteen patients with major surgery had slightly elevated S-VEGF compared with the preoperative level (median 9.5 pg/mL) on the first (median 35 pg/mL; P = 0.0002) and third (median 19 pg/mL; P = 0.004) postoperative day, but not in later samples. The levels measured in 8 patients after minor surgery did not differ from the preoperative levels (P = 0.14).\Question: Does major surgery increase serum levels of vascular endothelial growth factor only temporarily?
Output (English): Even major surgery is associated only with a slight and transient increase in S-VEGF levels, and, therefore, is unlikely to interfere markedly with the use of VEGF as a prognostic marker.