Minimally invasive colorectal resection for cancer is associated with a short-lived decrease in soluble Tie-2 receptor levels, which may transiently inhibit VEGF-mediated angiogenesis (via altered blood levels of free Ang-1 and Ang-2).
BACKGROUND
Angiopoetin- (Ang-) 1 inhibits and Ang-2 promotes VEGF-mediated angiogenesis via binding to endothelial cell-bound Tie-2 receptor (Tie-2). After minimally invasive colorectal resection (MICR), Ang-1 levels decrease and Ang-2 levels increase, which may stimulate angiogenesis in wounds and residual tumor foci. Soluble Tie-2 (sTie-2) modulates the effects of free Ang-1 and Ang-2 by binding to them. This study assessed perioperative MICR plasma sTie-2 levels.


METHODS
Blood samples were taken preoperatively (PreOp) and on postoperative days (POD) 1 and 3 from 50 cancer and 53 benign disease MICR patients. In a subgroup, a fourth sample was taken between POD7 and POD13 and bundled as a single time point. sTie-2 levels (ng/ml) were determined via ELISA. The mean and SD were determined at each time point. The t test used for analysis.


RESULTS
PreOp plasma sTie-2 levels were significantly higher in the benign group (27.6 ± 10.2) than in the cancer group (22.9 ± 7.9). A significant drop from PreOp occurred in sTie-2 levels in the cancer group on POD1 (20.0 ± 7.4) and POD3 (21.0 ± 6.6) and in the benign group on POD1 (24.8 ± 9.1). The benign group's POD3 and the cancer group's POD7-13 sTie-2 levels were statistically similar to the PreOp levels while the benign group's POD7-13 level was significantly higher.


CONCLUSIONS
PreOp sTie-2 levels were significantly lower in cancer patients. MICR is associated with a significant short-lived decrease in plasma sTie-2 levels in cancer patients on POD1 and 3, which may briefly inhibit VEGF-mediated angiogenesis. The benign group's early results were similar.
Shantha Kumara
H M C
HM
Division of Colon and Rectal Surgery, Department of Surgery, St. Luke's-Roosevelt Hospital Center, Suite 7B, 425 West 59th Street, New York, NY 10019, USA. hmsach_6@yahoo.com
Grieco
Michael J
MJ
Yan
Xiaohong
X
Kalady
Matthew F
MF
DiMaggio
Vincent
V
Kim
Donald G
DG
Hyman
Neil
N
Feingold
Daniel L
DL
Whelan
Richard L
RL
D000368:Aged; D042702:Angiopoietin-2 / Q000097:blood* / Q000502:physiology; D003082:Colectomy; D015179:Colorectal Neoplasms / Q000097:blood / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D009389:Neovascularization, Pathologic / Q000503:physiopathology*; D042787:Receptor, TIE-2 / Q000097:blood*; D012007:Rectum / Q000601:surgery*; D042442:Vascular Endothelial Growth Factors / Q000502:physiology*
D042702:Angiopoietin-2; D042442:Vascular Endothelial Growth Factors; D042787:Receptor, TIE-2