Plasma levels of angiostatin and endostatin remain unchanged for the first 3 weeks after colorectal cancer surgery.

INTRODUCTION: Angiostatin and endostatin are endogenous inhibitors of angiogenesis with anticancer effects. After minimally invasive colorectal resection (MICR), blood levels of the proangiogenic factors vascular endothelial growth factor (VEGF) and angiopoetin 2 (Ang-2) are elevated for 2-4 weeks. Also, postoperative human plasma from weeks 2 and 3 after MICR has been shown to stimulate endothelial cell proliferation and migration, which are critical to angiogenesis. This proangiogenic state may stimulate tumor growth early after MICR. Surgery's impact on angiostatin and endostatin is unknown. This study's purpose is to determine perioperative plasma levels of these two proteins in colorectal cancer (CRC) patients undergoing MICR. METHODS: Endostatin levels were assessed in 34 CRC patients and angiostatin levels in 30 CRC patients. Blood samples were taken preoperatively and on postoperative day (POD) 1 and 3 in all patients; in a subset, samples were taken between POD 7 and 20. The late samples were bundled into 7-day blocks (POD 7-13, POD 14-20) and considered as single time points. Angiostatin and endostatin plasma levels were determined via enzyme-linked immunosorbent assay (ELISA) in duplicate. Wilcoxon signed-rank test and Student's t test were used to analyze endostatin and angiostatin data, respectively. Significance was set at P<0.0125 (after Bonferroni correction). RESULTS: There was a significant decrease in median plasma endostatin levels on POD 1, which returned to the preoperative level by POD 3. There was no significant difference between pre- and postoperative plasma angiostatin levels. CONCLUSIONS: MICR has a very transient impact on plasma levels of endostatin and no impact on angiostatin during the first 21 days following surgery. Thus, angiostatin and endostatin do not likely contribute to or inhibit the persistent proangiogenic changes noted after MICR.

Minimally invasive colorectal resection is associated with a transient increase in plasma hepatocyte growth factor levels early after surgery for colon cancer.

INTRODUCTION: Surgery's impact on blood levels of hepatocyte growth factor (HGF), a potent angiogenic factor, is unknown. Preoperative (PreOp) HGF blood levels are elevated in patients with colorectal cancer (CRC) and correlate with disease stage and prognosis. This study's purpose was to determine plasma HGF levels after minimally invasive colorectal resection (MICR) in patients with CRC. METHODS: Clinical and operative data were collected. Blood samples were obtained in all patients PreOp and on postoperative day (POD) 1 and 3; in some, samples were taken during weeks 2 and 3 after MICR. Late samples were bundled into 7-day time blocks. HGF levels were determined via enzyme-linked immunosorbent assay in duplicate. Student's t test was used to analyze the data (significance, P < .0125 after Bonferroni correction). RESULTS: A total of 28 CRC patients who underwent MICR were studied. Most had right, sigmoid, or left segmental colectomy. The mean plasma HGF level was higher on POD 1 (2417 ± 1476 pg/mL, P < .001) and POD 3 (2081 ± 1048 pg/mL, P < .001) when compared with PreOp levels (1045 ± 406 pg/mL). Plasma levels were back to baseline by the second (1100 ± 474 pg/mL, P = .64) and third postoperative weeks (1010 ± 327 pg/mL, P = .51). CONCLUSION: MICR for CRC is associated with a 1.9- to 2.3-fold increase in plasma HGF levels during the first 3 PODs after which levels normalize. This transient increase may briefly promote angiogenesis and the growth of residual tumor cells.