Persistent elevation of plasma vascular endothelial growth factor levels during the first month after minimally invasive colorectal resection

Osteopontin Levels Are Persistently Elevated for 4 weeks Following Minimally Invasive Colorectal Cancer Resection

INTRODUCTION

Osteopontin (OPN) is an integrin binding phosphorylated glycoprotein secreted by macrophages and leukocytes that is found in extracellular fluids and sites of inflammation; various forms of CD44 serve as receptors. Osteopontin, expressed by numerous cancers, enhances tumor progression and angiogenesis via the PI3K/AKT and ERK mediated pathways in concert with Vascular Endothelial Growth Factor (VEGF); OPN also plays a role in wound healing. The impact of minimally invasive colorectal resection (MICR) for colorectal cancer (CRC) on plasma OPN levels is unknown. This study's goal was to assess blood levels during the first month after MICR.

METHOD

Patients undergoing MICR for CRC who were enrolled in an IRB approved tissue/prospective data bank for whom preoperative, postop Day (POD) 1, POD 3, and at least 1 late postop plasma sample (POD 7-34) were available were studied. Osteopontin levels were determined in duplicate via enzyme linked immunosorbent assay (ELISA) (results reported as mean ± SD). The Wilcoxon signed rank test was used for analysis (significance P < .05).

RESULTS

A total of 101 CRC patients (63% colon and 37% rectal) met study criteria. The mean preop OPN level was 89.2 ± 36.8 (ng/ml) for the entire group. Significantly elevated (P < .001) mean plasma levels were detected, vs preop, on POD1 (198.0 ± 67.4; n = 101), POD 3 (186.0 ± 72.6, n = 101), POD 7-13 (154.1 ± 70.2, n = 70), POD14-20 (146.7 ± 53.4, n=32), and POD 21-27 (123.0 ± 56.9, n = 25). No difference was noted at the POD 27-34 timepoint (P > .05).

CONCLUSION

Plasma OPN levels are significantly elevated over baseline for a month after MICR for CRC. The early rise in OPN levels may be related to the postop acute inflammatory response. The persistent elevation noted in weeks 2-4, however, may be a manifestation of wound healing in which OPN plays a role. Similar persistent plasma elevations of VEGF, angiopoietin 2 (ANG 2), and 11 other proangiogenic proteins have been noted and, collectively, may promote angiogenesis in residual tumors.

Sustained postoperative plasma elevations of plasminogen activator inhibitor-1 following minimally invasive colorectal cancer resection

Plasminogen activator inhibitor-1 (PAI-1) is a serine protease inhibitor that inhibits urokinase-type plasminogen activator and tissue-type plasminogen activator. PAI-1 participates in angiogenesis, wound healing and tumor invasion, and additionally regulates endothelial cell proliferation, angiogenesis and tumor growth. The purpose of the present study was to measure plasma PAI-1 levels perioperatively in patients with colorectal cancer (CRC) undergoing minimally invasive colorectal resection (MICR). Patients with CRC who underwent elective MICR were eligible for the study. All patients were enrolled in an approved data/plasma bank. Patients with preoperative, postoperative day (POD) 1, POD 3, and at least one POD 7-34 plasma sample collection were studied. Plasma PAI-1 levels were determined in duplicate using ELISA, and the medians and 95% confidence intervals (CIs) were determined. The correlations between postoperative plasma PAI-1 levels and length of surgery were evaluated. PAI-1 levels were compared between patients who underwent laparoscopic-assisted vs. hand-assisted surgery. The preoperative PAI-1 levels of stage I, II, III and IV pathological stage subgroups were also compared. A total of 91 patients undergoing MICR for CRC were studied. The mean incision length was 8.0±3.9 cm, and the length of stay was 6.8±4.3 days. Compared with the median preoperative levels (17.30; 95% CI: 15.63-19.78 ng/ml), significantly elevated median levels were observed on POD 1 (28.86; 95% CI: 25.46-31.22 ng/ml; P<0.001), POD 3 (18.87; 95% CI: 17.05-21.78 ng/ml; P=0.0037), POD 7-13 (26.97; 95% CI: 22.81-28.74 ng/ml; P<0.001), POD 14-20 (25.92; 95% CI: 17.85-35.89 ng/ml; P=0.001) and POD 21-27 (22.63; 95% CI: 20.03-30.09 ng/ml; P<0.001). The PAI-1 levels in the hand-assisted group were higher compared with those in the laparoscopic-assisted group for 4 weeks after surgery; however, a significant difference was found only on POD 1. Therefore, plasma PIA-1 levels were found to be significantly elevated for 4 weeks after MICR, and the surgery-related acute inflammatory response may account for the early postoperative PIA-1 increase. Furthermore, PAI-1-associated VEGF-induced angiogenesis in the healing wounds may account for the late postoperative elevations, and increased PAI-1 levels may promote angiogenesis in residual tumor deposits.

Plasma Levels of Keratinocyte Growth Factor Are Significantly Elevated for 5 Weeks After Minimally Invasive Colorectal Resection Which May Promote Cancer Recurrence and Metastasis

Background: Human Keratinocyte Growth Factor (KGF) is an FGF family protein produced by mesenchymal cells. KGF promotes epithelial cell proliferation, plays a role in wound healing and may also support tumor growth. It is expressed by some colorectal cancers (CRC). Surgery's impact on KGF levels is unknown. This study's purpose was to assess plasma KGF levels before and after minimally invasive colorectal resection (MICR) for CRC. Aim: To determine plasma KGF levels before and after minimally invasive colorectal resection surgery for cancer pathology. Method: CRC MICR patients (pts) in an IRB approved data/plasma bank were studied. Pre-operative (pre-op) and post-operative (post-op) plasma samples were taken/stored. Late samples were bundled into 7 day blocks and considered as single time points. KGF levels (pg/ml) were measured via ELISA (mean ± SD). The Wilcoxon paired t-test was used for statistical analysis. Results: Eighty MICR CRC patients (colon 61%; rectal 39%; mean age 65.8 ± 13.3) were studied. The mean incision length was 8.37 ± 3.9 and mean LOS 6.5 ± 2.6 days. The cancer stage breakdown was; I (23), II (26), III (27), and IV (4). The median pre-op KGF level was 17.1 (95 %CI: 14.6-19.4; n = 80); significantly elevated (p < 0.05) median levels (pg/ml) were noted on post-op day (POD) 1 (23.4 pg/ml; 95% CI: 21.4-25.9; n = 80), POD 3 (22.5 pg/ml; 95% CI: 20.7-25.9; n = 76), POD 7-13 (21.8 pg/ml; 95% CI: 17.7-25.4; n = 50), POD 14-20 (20.1 pg/ml; 95% CI: 17.1-23.9; n = 33), POD 21-27 (19.6 pg/ml; 95% CI: 15.2-24.9; n = 15) and on POD 28-34 (16.7 pg/ml; 95% CI: 14.0-25.8; n = 12). Conclusion: Plasma KGF levels were significantly elevated for 5 weeks after MICR for CRC. The etiology of these changes is unclear, surgical trauma related acute inflammatory response and wound healing process may play a role. These changes, may stimulate angiogenesis in residual tumor deposits after surgery.

Plasma MMP-2 and MMP-7 levels are elevated first month after surgery and may promote growth of residual metastases

BACKGROUND

MMP-2 also known as gelatinase A and MMP-7 (matrilysin) are members of the zinc-dependent family of MMPs (Matrix metalloproteinase). MMP-2 and MMP-7 are remodeling enzymes that digest extracellular matrix; MMP-2 is extensively expressed during development and is upregulated at sites of tissue damage, inflammation, and in stromal cells of metastatic tumors. MMP-7 is expressed in the epithelial cells and in a variety of cancers including colon tumors. Plasma MMP-2 and MMP-7 levels were assessed before and after minimally invasive colorectal resection for cancer pathology.

AIM

To determine plasma MMP-2 and MMP-7 levels before and after minimally invasive colorectal resection for cancer pathology.

METHODS

Patients enrolled in a plasma bank for whom plasma was available were eligible. Plasma obtained from preoperative (Preop) and postoperative blood samples was used. Only colorectal cancer (CRC) patients who underwent elective minimally invasive cancer resection with preop, post-operative day (POD) 1, 3 and at least 1 late postop sample (POD 7-34) were included. Late samples were bundled into 7 d blocks (POD 7-13, 14-20, etc.) and treated as single time points. Plasma MMP-2 and MMP-7 levels were determined via enzyme-linked immunosorbent assay in duplicate.

RESULTS

Total 88 minimally invasive CRC resection CRC patients were studied (right colectomy, 37%; sigmoid, 24%; and LAR/AR 18%). Cancer stages were: 1, 31%; 2, 30%; 3, 34%; and 4, 5%. Mean Preop MMP-2 plasma level (ng/mL) was 179.3 ± 40.9 (n = 88). Elevated mean levels were noted on POD1 (214.3 ± 51.2, n = 87, P < 0.001), POD3 (258.0 ± 63.9, n = 80, P < 0.001), POD7-13 (229.9 ± 62.3, n = 65, P < 0.001), POD 14-20 (234.9 ± 47.5, n = 25, P < 0.001), POD 21-27 (237.0 ± 63.5, n = 17, P < 0.001,) and POD 28-34 (255.4 ± 59.7, n = 15, P < 0.001). Mean Preop MMP-7 level was 3.9 ± 1.9 (n = 88). No significant differences were noted on POD 1 or 3, however, significantly elevated levels were noted on POD 7-13 (5.7 ± 2.5, n = 65, P < 0.001), POD 14-20 (5.9 ± 2.5, n = 25, P < 0.001), POD 21-27 (6.1 ± 3.6, n = 17, P = 0.002) and on POD 28-34 (6.8 ± 3.3, n = 15 P < 0.001,) vs preop levels.

CONCLUSION

MMP-2 levels are elevated for 5 wk and MMP-7 levels elevated for weeks 2-6. The etiology of these changes in unclear, trauma and wound healing likely play a role. These changes may promote residual tumor growth and metastasis.

Plasma and wound fluid levels of eight proangiogenic proteins are elevated after colorectal resection

BACKGROUND

Colorectal resection is associated with 3-5 wk long elevations in the plasma levels of at least 11 proangiogenic proteins that may stimulate tumor angiogenesis post-surgery. The increases during the first week after surgery may be related to the acute inflammatory response; the cause(s) of the week 2-5 increases is unknown. The wounds are a possible source because of the important role that angiogenesis plays in the healing process. The main hypothesis of the study is that wound fluid levels of the proteins studied will be elevated well beyond plasma levels which, in turn, are elevated from preoperative baseline levels.

AIM

To determine plasma and wound fluid levels of 8 proangiogenic proteins after colorectal resection for cancer and benign pathology.

METHODS

Blood and wound fluid samples were taken simultaneously on postoperative (postop) day 1, 3, and later time points until wound drain removal in 35 colorectal cancer patients and 31 benign disease patients undergoing colorectal resection in whom closed wound drains had been placed in either the pelvis or the subcutaneous space of the abdominal incision. Postop plasma levels were compared to preop plasma and postop wound fluid levels (separate analyses for cancer and benign groups).

RESULTS

Sixty-six colorectal disease patients were studied (35 cancer, 31 benign pathology). Most patients underwent minimally invasive surgery (open surgery in 11% of cancer and 6% of benign patients). The majority in the cancer group had rectal resections while in the benign group sigmoid or right colectomy predominated. Plasma levels of all 8 proteins were significantly elevated from baseline (P < 0.05) at all post-operative time points in the cancer group and at 90% of time points (29/32) in the benign group. Wound levels of all 8 proteins were 3-106 times higher (P < 0.05) than plasma levels at 87-90 percent of postop time points; of note, wound levels were more than 10 times higher at 47-50% of time points.

CONCLUSION

Plasma protein levels were elevated for 3 weeks after surgery; wound fluid levels were much greater than corresponding blood levels. Healing wounds may be the source of the plasma increases.

Plasma levels of the proangiogenic protein CXCL16 remains elevated for 1 month after minimally invasive colorectal cancer resection

BACKGROUND

Inflammation-induced endothelial precursor cell recruitment and angiogenesis are thought to be associated with CXCL16-CXCR6 pair activity. This study's main purpose was to determine plasma CXCL16 levels after minimally invasive colorectal resection (MICR) for colorectal cancer (CRC); an adjunct study assessed wound fluid (WF) and plasma CXCL16 levels in a separate group of CRC patients.

METHODS

CRC patients who had MICR and for whom plasma was available in a tissue bank were eligible. Plasma samples were collected preoperatively from all patients. Samples were also collected on postoperative days (POD) 1 and 3 and at various late postoperative time points (POD 7-34). In a separate study, blood and intra-abdominal wound fluid (WF) samples were collected from CRC MICR patients (pts). Samples were stored at - 80 °C. CXCL16 levels were determined via ELISA. The Wilcoxon signed-rank and Mann and Whitney tests were used for analysis.

RESULTS

Main study: 86 CRC pts. were included. The mean preoperative plasma CXCL16 level was 2.36 ± 0.57 ng/ml. Elevated mean plasma levels (p <  0.0001 × first 4 time points) were noted on POD 1 (2.82 ± 0.81, n = 86), POD 3 (3.12 ± 0.77, n = 82), POD 7-13 (3.28 ± 0.88, n = 64), POD 14-20 (3.03 ± 0.62, n = 24), POD 21-27 (3.06 ± 0.67, n = 20, p = 0.0003), and POD 28-34 (3.17 ± 0.43, n = 11, p = 0.001) vs. preop levels. WF study: In the adjunct study, plasma and WF CXCL16 levels were determined for 23 CRC MICR pts. WF levels at all time points were significantly elevated over plasma levels.

CONCLUSION

Plasma CXCL16 levels were elevated for 4 weeks after minimally invasive colorectal resection for cancer. Also, WF CXCL16 levels were 3-10 times greater than the corresponding plasma concentrations. The source of the late plasma elevations may be the healing wound. Increased plasma CXCL16 levels may promote tumor angiogenesis in the first month after MICR.

Plasma interleukin-8 levels are persistently elevated for 1 month after minimally invasive colorectal resection for colorectal cancer

Minimally invasive colorectal resection (MICR) for colorectal cancer (CRC) is associated with elevated levels of seven proangiogenic proteins that persist for 2-4 weeks after surgery. The proangiogenic plasma may promote tumor growth postoperatively in patients with residual cancer. To the best of our knowledge, the impact of surgery on interleukin 8 (IL-8) levels is unknown. The aim of the present study was to evaluate plasma IL-8 levels after MICR for CRC. Patients with CRC enrolled in an institutional review board-approved plasma/data bank who underwent MICR were eligible. Blood samples were taken preoperatively (preop) and at multiple postoperative (postop) time points, and were stored at -80°C. Only patients for whom preop, postop day (POD) 1, POD 3 and at least 1 late postop plasma samples (POD7-34) available were enrolled. Clinical, demographical and pathological data were collected. IL-8 levels were determined via ELISA and results were reported as the mean and ± standard deviation. The Wilcoxon signed rank test was used for analysis with P<0.05 used as the significance threshold. A total of 73 CRC patients (colon, 62%; rectal, 38%) who underwent MICR (laparoscopic-assisted, 60%; hand-assisted, 40%) were studied. The mean preop IL-8 level was 20.4±10.6 pg/ml. Significant elevations in plasma IL-8 levels were noted compared with preop levels on POD1 (43.1±38.6; n=72; P<0.0001), POD 3 (33.0±30.1; n=71; P<0.0001), POD7-13 (29.9±21.9; n=50; P<0.0001), POD14-20 (33.1±18.3; n=24; P=0.002), and for the POD21-27 time point (24.0±9.2; n=16; P=0.002). In conclusion, plasma IL-8 levels were significantly elevated from baseline for 4 weeks after MICR for CRC. In conjunction with the other proangiogenic MICR-associated blood compositional changes, increased IL-8 levels may promote tumor angiogenesis and growth postop.

In Surgical Colon Cancer Patients Extended-Duration Thromboprophylaxis (30 days) with the Highest Dose of Tinzaparin (4,500 IU s.c./q.d.) Normalizes the Postoperative VEGF Levels

Background/Purpose: In colon cancer (CC) patients preoperative (pre-op) levels of VEGF-A₁₆₅ (VEGF) is a strong predictor for disease recurrence. Elevated postoperative (post-op) VEGF levels could have undesirable effects by enhancing tumor growth and metastasis formation. It has been suggested that thromboprophylaxis with a Low Molecular Weight Heparin (LMWH) in surgical cancer patients, further to thromboembolic protection, may exert some anti-neoplastic properties, as well. The aim of our study was to assess the potential impact of the LMWH Tinzaparin (Innohep® - Leo Pharma, Copenhagen, Denmark), given at different doses and for different perioperative (peri-op) periods, upon the post-op variability of serum VEGF levels in surgical CC patients. Methods: A total of 54 consecutive CC patients who underwent a curative resection were randomized in four groups according to their peri-op thromboprophylaxis scheme, which was based on administrating Tinzaparin in different doses and at different periods, as follows: group I: 3,500 IU for 10 days, group II: 3,500 IU for 30 days, group III: 4,500 IU for 10 days and group IV: 4,500 IU for 30 days. Serum VEGF concentrations were evaluated on the pre-op day (Day 0) and on the 10^th and 30^th post-op days (Day 10 and Day 30, respectively). For statistical analyses the mixed design ANOVA was used. P < 0.05 was considered significant. Results: On Day 0, VEGF didn't differ between groups I, II, III and IV (p>0.05, for every comparison). On Day 10, VEGF was increased in all groups. Between Day 10 and Day 30, VEGF remained stable in groups I (p=0.031) and II (p=1.000) and increased significantly in group III (p=0.005). On the contrary, VEGF decreased significantly in group IV (p<0.001). The most remarkable finding was observed when we compared VEGF between Day 0 and Day 30: while in groups I, II and III, VEGF remained significantly higher compared to Day 0 (p<0.001, p=0.041 and p<0.001, respectively), on the contrary, in group IV (extended-duration with the highest dose of 4,500 IU of tinzaparin) it was comparable to Day 0 (p=1.000). Conclusions: In surgical CC patients only the recommended thromboprophylaxis scheme with the highest prophylactic dose of Tinzaparin (4,500 IU) for extended-duration (30 days) normalizes VEGF levels at the end of the first post-op month by reducing them to the pre-op levels.

Postoperative serum Vascular Endothelial Growth Factor is an independent prognostic factor of disease free survival and overall survival in patients with non metastatic colon cancer

BACKGROUND

Angiogenesis is essential for tumor growth and formation of metastasis. VEGF is the most potent agiogenic citokine. The aim was to investigate the predictive value of postoperative VEGF serum concentration in patients undergoing surgery for colon cancer.

METHODS

Consecutive patients with colon cancer undergoing surgery with curative intent were included. VEGF was measured in serum at 48 h and postoperative day 4. Cox proportional hazards model was used to estimate its contribution with prognosis.

RESULTS

A total of 94 patients were included. On multivariate analysis VEGF on postoperative day 4 (HR: 1.05; p = 0.011) was independent prognostic factor of decreased DFS and OS. Five-year DFS (57.7% vs. 85%; p = 0.001) and OS (93% vs. 72%; p = 0.005) were significantly lower in patients with postoperative serum VEGF greater than 370 pg/dl.

CONCLUSION

Postoperative VEGF serum concentration was an independent predictor of recurrence. These results must be verified in a prospective independent testing cohort.

Laparoscopic colectomy for cancer: Improved compliance with guidelines for chemotherapy and survival

BACKGROUND

Laparoscopic surgery for colon cancer has been demonstrated in clinical trials to have short-term benefits when compared to the open surgical approach. Guidelines of the National Comprehensive Cancer Network recommend that patients with stage III or high-risk stage II colon cancer undergo adjuvant chemotherapy. We hypothesized that laparoscopic colectomy is associated with increased compliance to recommendations for chemotherapy, a lesser time to start of chemotherapy, and increased overall survival.

METHODS

The National Cancer Data Base was queried to identify patients with stage III or high-risk stage II colon cancer (T4, positive margins, <12 lymph nodes, or high tumor grade) diagnosed 2010-2012. Patients were divided into laparoscopic colectomy and open colectomy groups. Intent-to-treat analysis was used with converted cases included in the laparoscopic colectomy group. Rates of receiving adjuvant chemotherapy, time from diagnosis and date of operation to start of chemotherapy, and overall survival were compared.

RESULTS

A total of 48,257 patients were included for analysis; 18,801 patients underwent laparoscopic colectomy and 29,456 underwent open colectomy. Laparoscopic colectomy patients received adjuvant chemotherapy at a somewhat greater rate than open colectomy (66.2% vs 59.4%, P < .01). Among patients who received chemotherapy, mean time to start of chemotherapy after definitive resection was somewhat less for laparoscopic colectomy than open colectomy (48.7 vs 52.7 days, P < .01). Two-year overall survival was greater for laparoscopic colectomy than open colectomy (81.9% vs 73.2%, P < .01).

CONCLUSION

Compared to open colectomy, laparoscopic colectomy is associated with somewhat greater rates of compliance with guidelines for adjuvant chemotherapy for stage III and high-risk stage II colon cancer, as well as a slightly lesser time to start of chemotherapy and improved overall survival.

Five year follow-up of a randomized controlled trial on warming and humidification of insufflation gas in laparoscopic colonic surgery--impact on small bowel obstruction and oncologic outcomes

Warming and humidification of insufflation gas has been shown to reduce adhesion formation and tumor implantation in the laboratory setting, but clinical evidence is lacking. We aimed to test the hypothesis that warming and humidification of insufflation CO2 would lead to reduced adhesion formation, and improve oncologic outcomes in laparoscopic colonic surgery. This was a 5-year follow-up of a multicenter, double-blinded, randomized, controlled trial investigating warming and humidification of insufflation gas. The study group received warmed (37°C), humidified (98%) insufflation carbon dioxide, and the control group received standard gas (19°C, 0%). All other aspects of patient care were standardized. Admissions for small bowel obstruction were recorded, as well as whether management was operative or nonoperative. Local and systemic cancer recurrence, 5-year overall survival, and cancer specific survival rates were also recorded. Eighty two patients were randomized, with 41 in each arm. Groups were well matched at baseline. There was no difference between the study and control groups in the rate of clinical small bowel obstruction (5.7% versus 0%, P 0.226); local recurrence (6.5% versus 6.1%, P 1.000); overall survival (85.7% versus 82.1%, P 0.759); or cancer-specific survival (90.3% versus 87.9%, P 1.000). Warming and humidification of insufflation CO2 in laparoscopic colonic surgery does not appear to confer a clinically significant long term benefit in terms of adhesion reduction or oncological outcomes, although a much larger randomized controlled trial (RCT) would be required to confirm this. ClinicalTrials.gov Trial identifier: NCT00642005; US National Library of Medicine, 8600 Rockville Pike, Bethesda, MD 20894, USA.

Effect and clinical significance of fast-track surgery combined with laparoscopic radical gastrectomy on the plasma level of vascular endothelial growth factor in gastric antrum cancer

This study discusses the effect and clinical significance of fast-track surgery (FTS) combined with laparoscopic radical surgery on the plasma level of vascular endothelial growth factor (VEGF) in locally advanced gastric antrum cancer. Plasma VEGF levels were detected in 63 cases of locally advanced gastric antrum cancer by using double-antibody sandwich Avidinbiotincomplex-ELISA before and after operation. The pure laparoscopic surgery group (group A) comprised 30 cases, and the combined FTS group (group B) consisted of 33 cases. Results of the two groups were obtained at similar time points and then compared. The VEGF levels were not significantly different between the two groups on the first day before the operation and on the first day, third day, and sixth month after the operation (P > 0.05). However, the differences were significant on the seventh day and first month after the operation (P < 0.05). The postoperative eating time, anal exhaust time, and hospital stay of the patients were statistically significantly different between the two groups (P < 0.05). Nevertheless, no significant differences were detected in terms of wound healing time and complications (P > 0.05). The 3-year survival rate significantly differed between the two groups (P < 0.05). FTS combined with laparoscopic surgery can decrease the postoperative VEGF level compared with pure laparoscopic surgery. The combined approach improved postoperative recovery without prolonging the wound healing time or increasing the incidence of postoperative complications. The 3-year survival rate also increased. Thus, FTS combined with laparoscopic surgery can improve the prognosis in gastric antrum cancer.

Minimally invasive colorectal resection is associated with significantly elevated levels of plasma matrix metalloproteinase 3 (MMP-3) during the first month after surgery which may promote the growth of residual metastases

INTRODUCTION

MMP-3, a member of the matrix metalloproteinase (MMP) family, is involved in the breakdown of the extracellular matrix in tissue remodeling and may also play a role in cancer progression and metastasis. Minimally invasive colorectal resection (MICR) may increase plasma MMP-3 levels directly via surgical trauma or indirectly due to surgery-associated elevations in TNF-α and IL1 which are regulators of MMP-3. This study's purpose was to evaluate plasma MMP-3 levels during the first month after MICR for colorectal cancer.

METHODS

Patients enrolled in an IRB approved data/plasma bank who underwent elective MICR for CRC. Blood plasma samples had been collected preoperatively, on postoperative day (POD) 1, 3 and at varying postoperative time points and were stored at -80 °C. The late samples (POD 7-41) were bundled into 7 day time blocks and considered as single time points. MMP-3 levels were analyzed in duplicate via ELISA and the results reported as mean ± SD. The paired t test was used for analysis (significance, p < 0.008 after Bonferroni's correction).

RESULTS

A total of 73 CRC patients who underwent MICR met the inclusion criteria. The mean PreOp MMP-3 level was 14.9 ± 7.8 ng/ml (n = 73). Significantly elevated mean plasma levels were noted on POD 1 (21.4 ± 14.7 ng/ml, n = 73, p < 0.0001), POD 3 (37.9 ± 21.5 ng/ml, n = 72, p < 0.0001), POD 7-13 (22.0 ± 13.0 ng/ml, n = 56, p < 0.0001), POD 14-20 (21.9 ± 10.3 ng/ml, n = 20, p = 0.003), and on POD 21-27 (21.9 ± 11.43 ng/ml, n = 20, p = 0.002) when compared to PreOp levels. Plasma levels returned to the PreOp baseline at the POD 28-41 time point (n = 16, p = 0.07).

CONCLUSION

Plasma MMP-3 levels remained significantly elevated from baseline for 4 weeks after MICR for CRC. The early postoperative increase in MMP-3 levels may be due to the surgery-related acute inflammatory response; the elevation noted during weeks 2-3 may be related to wound healing. Increased MMP-3 levels may promote metastases or the growth of residual cancer.

Minimally invasive colorectal resection for benign pathology is associated with persistent proangiogenic plasma compositional changes

BACKGROUND

Minimally invasive colorectal resection for cancer is associated with increased plasma levels of numerous proangiogenic proteins for 3 to 4 weeks postoperatively, and plasma from postoperative weeks 2 and 3 stimulates proangiogenic endothelial cell behavior in vitro. It is unknown if similar plasma changes occur after minimally invasive colorectal resection for benign pathology.

OBJECTIVE

The aim of this study is to assess 1) plasma levels of angiopoetin-2, placental growth factor, and soluble vascular cell adhesion molecule-1 after minimally invasive colorectal resection for benign pathology and 2) postoperative plasma's effects on in vitro endothelial cell proliferation (branch point formation), migration, and invasion.

DESIGN

Prospectively gathered plasma samples taken from patients undergoing colorectal resection who consented to participate in an institutional review board-approved plasma and data bank were used for ELISAs and in vitro endothelial cell studies.

SETTINGS

The plasma and clinical data used were collected at 3 hospitals.

PATIENTS

Patients undergoing minimally invasive colorectal resection for benign indications who were enrolled in a plasma/data bank and for whom adequate samples and volumes of plasma were available were included in the study.

MAIN OUTCOME MEASURES

Perioperative plasma levels of angiopoetin-2, placental growth factor, and soluble vascular cell adhesion molecule-1 were the primary outcomes measured. In vitro rates of endothelial cell branch point formation, migration, and invasion were determined after the addition of preoperative and postoperative plasma samples to endothelial cell cultures.

RESULTS

Plasma from 86 patients undergoing minimally invasive colorectal resection for benign indications was assessed (diverticulitis, 30; benign polyps, 56). Plasma levels of angiopoetin-2, placental growth factor, and soluble vascular cell adhesion molecule-1 were significantly increased for 3 to 4 weeks postoperatively compared with preoperative levels. In regard to the endothelial cell culture assays, significantly increased endothelial cell branch point formation, invasion, and migration results were noted with plasma from the second and third weeks postoperatively in comparison with preoperative culture results.

LIMITATIONS

The weaknesses of this study are the limited numbers of late postoperative plasma samples and the need to bundle late samples into 7- to 12-day time blocks.

CONCLUSIONS

Minimally invasive colorectal resection for benign pathology is associated with persistent proangiogenic plasma alterations similar to those found in patients who have cancer. Surgical trauma and not the indication is the likely cause.

Surgical trauma and immune functional changes following major lung resection

Video-assisted thoracic surgery (VATS) has evolved greatly over the last two decades. VATS major lung resection for early stage non-small cell lung carcinoma (NSCLC) has been shown to result in less postoperative pain, less pulmonary dysfunction postoperatively, shorter hospital stay, and better patient tolerance to adjuvant chemotherapy compared with patients who underwent thoracotomy. Several recent studies have even reported improved long-term survival in those who underwent VATS major lung resection for early stage NSCLC when compared with open technique. Interestingly, the immune status and autologous tumor killing ability of lung cancer patients have previously been associated with long-term survival. VATS major lung resection can result in an attenuated postoperative inflammatory response. Furthermore, the minimal invasive approach better preserve patients' postoperative immune function, leading to higher circulating natural killer and T cells numbers, T cell oxidative activity, and levels of immunochemokines such as insulin growth factor binding protein 3 following VATS compared with thoracotomy. Apart from host immunity, the angiogenic environment following surgery may also have a role in determining cancer recurrence and possibly survival. Whether differences in immunological and biochemical mediators contribute significantly towards improved clinical outcomes following VATS major lung resection for lung cancer remains to be further investigated. Future studies will also need to address whether the reduced access trauma from advanced thoracic surgical techniques, such as single-port VATS, can further attenuate the postoperative inflammatory response.

Prognostic and predictive value of serum vascular endothelial growth factor (VEGF) in squamous cell carcinoma of the head and neck

INTRODUCTION

This study aimed to investigate the prognostic and predictive value of serum vascular endothelial growth factor (VEGF) in head and neck squamous cell carcinoma (HNSCC).

METHOD

Preoperative and 6-month postoperative serum VEGF levels were measured using a quantitative sandwich enzyme immunoassay technique in 55 consecutive patients with HNSCC and two control groups. The first control group included normal, healthy, age- and sex-matched individuals (n = 20), while the second control group included the patients who had history of HNSCC and were free of disease for at least 5 years (n = 25).

RESULTS

The mean baseline serum VEGF concentrations of the 55 patients with HNSCC and the first and the second control groups were 437.86, 42.56, and 48.03 pg/ml, respectively (P < 0.001). After a median follow-up of 75 months, 15 patients of the study group developed recurrent disease and 40 patients remained free of disease. The mean preoperative and 6-month postoperative serum VEGF levels for the 40 patients who did not have recurrent disease were respectively 327.69 and 153.50 pg/ml compared to 731.72 and 692.96 pg/ml for the 15 patients with recurrent disease (P < 0.001). High (≥540 pg/ml) serum VEGF level was associated with poor overall survival (P < 0.001). Moreover, multivariate analysis showed node stage (P < 0.001) and preoperative serum VEGF level (P = 0.020) as significant, independent prognostic factors for overall survival.

CONCLUSION

Preoperative or postoperative elevated serum levels of VEGF are highly predictive for disease recurrence and are associated with poor disease-free and overall survival of patients with HNSCC.

Plasma levels of angiopoietin-like protein 4 (ANGPTL4) are significantly lower preoperatively in colorectal cancer patients than in cancer-free patients and are further decreased during the first month after minimally invasive colorectal resection

BACKGROUND

Surgery has been associated with proangiogenic plasma protein changes that may promote tumor growth. Angiopoietin-like protein 4 (ANGPTL4) is expressed by endothelial cells and other tissues in response to hypoxia. Both intact ANGPTL4 and its partly degraded C-terminal fragment may promote tumor angiogenesis. This study had two purposes: to measure and compare preoperative plasma ANGPTL4 levels in patients with colorectal cancer (CRC) and benign colorectal disease (BCD) and to determine plasma levels after minimally invasive colorectal resection (MICR) for CRC.

METHODS

Plasma was obtained from an IRB-approved plasma/data bank. Preoperative plasma ANGPTL4 levels were measured for CRC and BCD patients, but postoperative levels were determined only for CRC patients for whom a preoperative, a postoperative day (POD) 3, and at least one late postoperative sample (POD 7-55) were available. Late samples were bundled into four time blocks and considered as single time points. ANGPTL4 levels (mean ± SD) were measured via ELISA and compared (significance, p < 0.01 after Bonferroni correction).

RESULTS

Eighty CRC (71 % colon, 29 % rectal) and 60 BCD (62 % diverticulitis, 38 % adenoma) patients were studied. The mean preoperative plasma ANGPTL4 level in CRC patients (247.2 ± 230.7 ng/ml) was lower than the BCD group result (330.8 ± 239.0 ng/ml, p = 0.01). There was an inverse relationship between plasma levels and advanced CRC as judged by three criteria. In regard to the postoperative CRC analysis, the "n" for each time point varied: lower plasma levels (p < 0.001) were noted on POD 3 (161.4 ± 140.4 ng/ml, n = 80), POD 7-13 (144.6 ± 134.5 ng/ml, n = 46), POD 14-20 (139.0 ± 117.8 ng/ml, n = 27), POD 21-27 (138.9 ± 202.4, n = 20), and POD 28-55 (160.1 ± 179.0, n = 42) when compared to preoperative results.

CONCLUSION

CRC is associated with lower preoperative plasma ANGPTL4 levels compared with BCD, and the levels may vary inversely with disease severity. After MICR for CRC, levels are significantly lower for over a month compared with the preoperative level; the cause for this persistent decrease is unclear. The implications of both the lower preoperative level and the persistently decreased postoperative levels are unclear. Further studies are needed.

Time-dependent changes of plasma concentrations of angiopoietins, vascular endothelial growth factor, and soluble forms of their receptors in nonsmall cell lung cancer patients following surgical resection

Even when patients with nonsmall cell lung cancer undergo surgical resection at an early stage, recurrent disease often impairs the clinical outcome. There are numerous causes potentially responsible for a relapse of the disease, one of them being extensive angiogenesis. The balance of at least two systems, VEGF VEGFR and Ang Tie, regulates vessel formation. The aim of this study was to determine the impact of surgery on the plasma levels of the main angiogenic factors during the first month after surgery in nonsmall cell lung cancer patients. The study group consisted of 37 patients with stage I nonsmall cell lung cancer. Plasma concentrations of Ang1, Ang2, sTie2, VEGF, and sVEGF R1 were evaluated by ELISA three times: before surgical resection and on postoperative days 7 and 30. The median of Ang2 and VEGF concentrations increased on postoperative day 7 and decreased on day 30. On the other hand, the concentration of sTie2 decreased on the 7th day after resection and did not change statistically later on. The concentrations of Ang1 and sVEGF R1 did not change after the surgery. Lung cancer resection results in proangiogenic plasma protein changes that may stimulate tumor recurrences and metastases after early resection.

Plasma soluble vascular adhesion molecule-1 levels are persistently elevated during the first month after colorectal cancer resection

INTRODUCTION

Plasma from the second and third weeks after minimally invasive colorectal resection (MICR) has high levels of the proangiogenic proteins VEGF and angiopoietin 2 and also stimulates, in vitro, endothelial cell (EC) proliferation and migration, which are critical to wound and tumor angiogenesis. Soluble vascular cell adhesion molecule-1 (sVCAM-1) stimulates EC chemotaxis and angiogenesis. The impact of MICR on blood levels of sVCAM-1 is unknown. This study's purpose was to determine plasma sVCAM-1 levels after MICR in colorectal cancer (CRC) patients.

METHODS

Blood samples from 90 patients (26% rectal, 74% colon) were obtained preoperatively, on postoperative days (POD) 1 and 3, and at other points during the next 2 months. The late samples were bundled into 7-day time blocks. sVCAM-1 levels were determined in duplicate via ELISA and reported as ng/ml. Student's t test was used for data analysis (significance, P < 0.008 after Bonferroni correction).

RESULTS

The mean incision length was 7.3 ± 3.1 cm, and the conversion rate was 3%. Compared with preoperative (PreOp) levels (811.3 ± 233.2), the mean plasma sVCAM-1 level was significantly higher on POD 1 (905.7 ± 292.4, P < 0.001) and POD 3 (977.7 ± 271.8, P < 0.001). Levels remained significantly elevated for the POD 7-13, POD 14-20, POD 21-27, and POD 28-67 time blocks.

CONCLUSIONS

MICR for CRC is associated with a persistent increase in plasma sVCAM-1 levels during the first month. This sustained increase may promote angiogenesis and stimulate the growth of residual tumor cells early after surgery.

Inflammatory and tumor stimulating responses after laparoscopic sigmoidectomy

PURPOSE

Laparoscopic colectomy has clinical benefits such as short hospital stay, less postoperative pain, and early return of bowel function. However, objective evidence of its immunologic and oncologic benefits is scarce. We compared functional recovery after open versus laparoscopic sigmoidectomy and investigated the effect of open versus laparoscopic surgery on acute inflammation as well as tumor stimulation.

MATERIALS AND METHODS

A total of 57 patients who were diagnosed with sigmoid colon cancer were randomized for elective conventional or laparoscopically assisted sigmoidectomy. Serum samples were obtained preoperatively and on postoperative day 1. C-reactive protein (CRP) and interleukin-6 (IL-6) were measured as inflammation markers, and vascular endothelial growth factor (VEGF) and insulin-like growth factor binding protein-3 (IGFBP-3) were used as tumor stimulation factors. Clinical parameters and serum markers were compared.

RESULTS

Postoperative hospital stay (p=0.031), the first day of gas out (p=0.016), and the first day of soft diet (p<0.001) were significantly shorter for the laparoscopic surgery group than the open surgery group. The levels of CRP, IL-6, and VEGF rose significantly, and the concentration of IGFBP-3 fell significantly after both open and laparoscopic surgery. However, there were no significant differences in the preoperative and postoperative levels of CRP, IL-6, VEGF, and IGFBP-3 between the two groups.

CONCLUSION

Our data suggest that both open and laparoscopic surgeries are accompanied by significant changes in IL-6, CRP, IGFBP-3, and VEGF levels. Acute inflammation markers and tumor stimulating factors may not reflect clinical benefits of laparoscopic surgery.

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.

Minimally invasive colon resection is associated with a persistent increase in plasma PlGF levels following cancer resection

BACKGROUND

Minimally invasive colorectal resection (MICR) is associated with persistently elevated plasma VEGF levels that may stimulate angiogenesis in residual tumor foci. Placenta growth factor (PlGF) stimulates neovascularization in tumors by modulating VEGF's effects. This study's purpose was to determine the impact of MICR on blood PlGF levels in cancer patients (Study A) and to compare PreOp levels in patients with cancer and benign (BEN) disease (Study B).

METHODS

Blood samples were collected preoperatively, on postoperative day (POD) 1, POD 3, and at various time points 2-4 weeks after surgery. Samples from 7-day periods after POD 6 were bundled to allow analysis. Plasma PlGF levels were determined via ELISA, results reported as mean±SD, and data analyzed via t test. Significance was set at p<0.008 after Bonferroni correction.

RESULTS

Study A: 76 colorectal cancer (CRC) patients had MICR (laparoscopic, 59%; hand-assisted, 41%). The mean length of stay was 5.8±2.1 days. The mean PreOp PlGF level was 15.4±4.3 pg/ml. Significantly increased levels were noted on POD 1 (25.8±7.7 pg/ml, p<0.001), POD 3 (22.9±6.7, p<0.001), POD 7-13 (19.2±5.1, p<0.001), and POD 14-20 (19.5±6.7, p<0.002). The mean POD 21-27 level was not significantly different from baseline. Study B included 126 CRC and 111 BEN patients. PreOp levels were higher in the CRC patients (15.6±5.3 pg/ml) than in the BEN group (13.5±5.5 pg/ml, p=0.001).

CONCLUSIONS

PlGF levels are elevated for 3 weeks after MICR and PreOp plasma levels are higher in CRC patients than in BEN disease patients. The cause of the postoperative increase is unclear. The persistently higher blood levels of PlGF and VEGF after MICR may stimulate angiogenesis in residual tumor foci. Further studies regarding late blood protein alterations after surgery appear to be indicated.

Minimally invasive colorectal resection is associated with a rapid and sustained decrease in plasma levels of epidermal growth factor (EGF) in the colon cancer setting

BACKGROUND

Epidermal growth factor (EGF) stimulates tumor growth directly via tumor cell EGF receptors or indirectly via its proangiogenic effects. This study's purpose was to determine the impact of minimally invasive colorectal resection (MICR) on postoperative (postop) plasma EGF levels in the colorectal cancer (CRC) and benign disease settings and to see if preoperative (PreOp) EGF levels are altered in cancer patients.

METHODS

MICR patients with benign pathology (n = 40) and CRC (n = 48) had blood samples taken PreOp and on postoperative days (POD) 1 and 3. In some patients, late samples were taken between POD7 and POD60; these were bundled into 7-day blocks and considered as single time points. EGF levels were determined by enzyme-linked immunosorbent assay (ELISA) and results were reported as mean ± SD after logarithmic transformation. The Student t test was used (p < 0.008 after Bonferroni correction).

RESULTS

The cancer and benign groups were comparable except for age. The mean PreOp CRC plasma EGF level (122.9 ± 75.9 pg/ml) was significantly higher than that of the benign group (85.3 ± 38.5 pg/ml) (p = 0.015). The cancer group's EGF levels were significantly decreased on POD1 and POD3 and for the POD31-55 time point (mean EGF level = 63.1 ± 42.2 (n = 10). The benign group's POD3 and POD7-14 EGF levels were significantly lower than the PreOp level; later levels returned toward baseline. Small late sample size limited analysis.

CONCLUSION

Plasma EGF levels are significantly higher in cancer patients. MICR is associated with a significant decrease in EGF levels early postop in both cancer and benign settings. Unlike the benign group, EGF blood levels in cancer patients remain low during the second postop month. A larger study with more late samples is needed to verify these results. EGF may have value as a tumor marker.

Minimally invasive surgery and cancer: controversies part 1

Perhaps there is no more important issue in the care of surgical patients than the appropriate use of minimally invasive surgery (MIS) for patients with cancer. Important advances in surgical technique have an impact on early perioperative morbidity, length of hospital stay, pain management, and quality of life issues, as clearly proved with MIS. However, for oncology patients, historically, the most important clinical questions have been answered in the context of prospective randomized trials. Important considerations for MIS and cancer have been addressed, such as what are the important immunologic consequences of MIS versus open surgery and what is the role of laparoscopy in the staging of gastrointestinal cancers? This review article discusses many of the key controversies in the minimally invasive treatment of cancer using the pro-con debate format.

Impact of Video-Assisted Thoracoscopic Major Lung Resection on Immune Function

Video-assisted thoracoscopic major lung resection for early stage non-small-cell lung carcinoma has been associated with less postoperative pain, better preserved pulmonary function, shorter hospital stay, and enhanced tolerance of adjuvant chemotherapy compared to thoracotomy. Initial concerns regarding safety, oncological clearance, and cost effectiveness were unfounded. Several recent trials have reported improved long-term survival in patients with early stage non-small-cell lung carcinoma undergoing video-assisted thoracoscopic major lung resection, compared to the open technique, although there are inconsistencies. Interestingly, the immune status and autologous tumor killing ability of lung cancer patients have previously been associated with long-term survival. Video-assisted thoracoscopic lung resection results in an attenuated postoperative inflammatory response, but more importantly, it better preserves postoperative immune function. Circulating natural killer and T-cell numbers, T-cell oxidative activity, and levels of immunochemokines such as insulin growth factor binding protein-3 are higher after video-assisted thoracoscopic surgery than after thoracotomy. Recently, interest has developed in the role of the angiogenesis factor, vascular endothelial growth factor, after cancer surgery. Whether differences in immunological and biochemical mediators contribute towards improved long-term survival following video-assisted thoracoscopic major lung resection for cancer remains to be confirmed.

Colorectal resection is associated with persistent proangiogenic plasma protein changes: postoperative plasma stimulates in vitro endothelial cell growth, migration, and invasion

INTRODUCTION

Plasma vascular endothelial growth factor (VEGF) levels are elevated for weeks after minimally invasive colorectal resection (MICR). Decreased plasma angiopoietin-(Ang) 1 and increased Ang-2 levels have been noted on postoperative days (POD) 1 and 3. These proangiogenic changes may stimulate tumor growth postoperatively (postop). This study's purpose was to track plasma VEGF, Ang-1, and Ang-2 levels for 4 to 8 weeks after MICR for cancer and to assess the impact of preoperative (preop) and postop plasma on in vitro endothelial cell (EC) behavior.

METHODS

Blood samples from 105 MICR patients were taken preop, on POD 5 and at varying time points for 2 months. Samples from 7 day time blocks after POD 5 were bundled to permit statistical analysis. Plasma protein levels were measured via enzyme-linked immunosorbent assay. In vitro EC branch point formation, EC invasion, and EC migration assays were carried out with preop, POD 7 to 13 and 14 to 20 plasma. The t test and Bonferonni correction was used.

RESULTS

VEGF levels were significantly elevated on POD 5 and 7 to 13; lesser increases were noted on POD 14 to 20 and 21 to 27. Ang-2 levels were significantly increased at all time points postop. No significant Ang-1 changes were noted. When compared to preop EC culture results, there was significantly more EC branch point formation, EC invasion, and EC migration assays noted with POD 7 to 13 and POD 14 to 20 plasma.

CONCLUSIONS

MICR is associated with proangiogenic plasma changes for 2 to 4 weeks and plasma from POD 7 to 13 and 14 to 20 stimulated EC growth, invasion, and migration. Postop plasma may stimulate the growth of residual tumor.

Preoperative serum vascular endothelial growth factor-a is a marker for subsequent recurrence in colorectal cancer patients

PURPOSE

Serum vascular endothelial growth factor-A has been associated with stage of disease and prognosis in colorectal cancer. In this study, the clinical usefulness of preoperative serum vascular endothelial growth factor-A concentrations in the long-term follow-up of colorectal cancer patients was evaluated.

METHODS

Serum vascular endothelial growth factor-A levels were determined by quantitative enzyme-linked immunosorbent assay in 93 patients prior to resection for colorectal cancer: node-negative (n = 41) and node-positive (n = 52). Median follow-up for patients without cancer death was 54 (interquartile range, 24-63.5) months.

RESULTS

The median preoperative serum vascular endothelial growth factor-A level of these patients was 168 (interquartile range, 48-414) pg/ml. Seven patients had local recurrences with a median time of 6 (interquartile range, 4-12) months. Patients (n = 17) that developed metastasis had a median time of 17 (interquartile range, 7-42) months. Patients with local recurrence had significantly higher levels of serum vascular endothelial growth factor-A (P = 0.01). By classifying the patients into two groups, using the maximal chi-squared value of the Cox's regression based on our previous work, it was found that a serum vascular endothelial growth factor-A level >575 pg/ml is an independent prognostic factor for predicting tumor recurrence.

CONCLUSION

Patients with colorectal cancer who have preoperative serum vascular endothelial growth factor-A levels >575 pg/ml are more likely to develop recurrence. Trials are warranted to investigate the efficacy of adjuvant therapy for this high-risk group.

Minimally invasive colon resection is associated with a transient increase in plasma sVEGFR1 levels and a decrease in sVEGFR2 levels during the early postoperative period

INTRODUCTION

Plasma vascular endothelial growth factor (VEGF) levels are elevated for 2-4 weeks after minimally invasive colorectal resection (MICR). VEGF induces wound and tumor angiogenesis by binding to endothelial cell (EC)-bound VEGF-receptor 1 (VEGFR1) and VEGFR2. Soluble receptors (sVEGFR1, sVEGFR2) sequester VEGF in the blood and decrease VEGF's proangiogenic effect. The importance of the MICR-related VEGF changes depends on the effect of surgical procedures on sVEGFR1 and sVEGFR2; this study assessed levels of these proteins after MICR for benign indications.

METHODS

Blood samples were taken (n=39) preoperatively (preop) and on postoperative days (POD) 1 and 3; in most cases a fourth sample was drawn between POD 7 and 30. sVEGFR1 and sVEGFR2 levels were measured via enzyme-linked immunosorbent assay (ELISA), which detects free and VEGF bound soluble receptor. Late samples were bundled into POD 7-13 and POD 14-30 time points. Results are reported as mean and standard deviation. The data was assessed with paired-samples t-test.

RESULTS

Preop, mean plasma sVEGFR2 level (9,203.7+/-1,934.3 pg/ml) was significantly higher than the sVEGFR1 value (132.5+/-126.2 pg/ml). sVEGFR2 levels were significantly lower on POD 1 (6,957.8+/-1,947.7 pg/ml,) and POD 3 (7,085.6+/-2,000.2 pg/ml), whereas sVEGFR1 levels were significantly higher on POD 1 (220.0+/-132.8 pg/ml) and POD 3 (182.7+/-102.1 pg/ml) versus preop results. No differences were found on POD 7-13 or 14-30.

CONCLUSIONS

sVEGFR2 values decreased and sVEGFR1 levels increased early after MICR; due to its much higher baseline, the sVEGFR2 changes dominate. The net result is less VEGF bound to soluble receptor and more free plasma VEGF.

Colorectal resection, both open and laparoscopic-assisted, in patients with benign indications is associated with proangiogenic changes in plasma angiopoietin 1 and 2 levels

INTRODUCTION

Plasma vascular endothelial growth factor (VEGF) levels are increased after surgery and may stimulate tumor growth after cancer resection. Angiopoietin 1 (Ang 1) and Ang 2 are proteins that impact VEGF-related angiogenesis (VRA). Ang 1 stabilizes mature vessels and inhibits VRA, whereas Ang 2 destabilizes vessels and promotes VRA. The ratio of Ang 1 to Ang 2 reflects the net effect; a low ratio promotes VRA. This study's purpose was to determine the impact of open and minimally invasive (MIS) colorectal resection (CR) for benign indications on plasma Ang 1 and 2 levels.

METHODS

A total of 30 patients operated by MIS and 26 operated by open procedure were studied. Plasma was obtained preoperatively (PO) and on postoperative days (POD) 1 and 3. Plasma Ang 1 and Ang 2 levels were assessed via enzyme-linked immunosorbent assay (ELISA) in duplicate. Data were compared using Wilcoxon's matched-pair test and the Mann-Whitney U-test (significance p < 0.05).

RESULTS

Indications, types of resection, and morbidity for the groups were similar. The mean MIS incision length was 4.7 +/- 1.6 cm while it was 16.8 +/- 7.1 cm for the open group (p = 0.0001). For both groups Ang 2 levels were significantly higher and the Ang 1 to Ang 2 ratio was significantly lower on POD 1 and 3 compared with preoperative results. Ang 1 levels were significantly decreased on POD 1 and 3 in the MIS group but only on POD 1 in the open group. For unclear reasons, preoperative Ang 1 levels and Ang 1 to Ang 2 ratios were significantly different between the groups, which precludes comparison of the postoperative results between groups.

CONCLUSION

CR for benign pathology results in higher Ang 2 levels, lower Ang 1 levels, and lower Ang 1 to Ang 2 ratios early after surgery. These alterations are proangiogenic. These results, plus the already noted VEGF increases, suggest that surgery results in proangiogenic plasma protein changes that may stimulate tumor growth early after surgery. The duration of the Ang 1 and 2 changes needs to be determined.

Perioperative GMCSF limits the proangiogenic plasma protein changes associated with colorectal cancer resection

AIMS

Colorectal resection (CR) increases plasma VEGF levels which may promote residual tumor growth. This study assessed the effect of perioperative GMCSF on plasma levels of sVEGFR1, Ang-1 and Ang-2 and also the impact of post-GMCSF plasma on in vitro endothelial cell (EC) growth and invasion. Ang-2 increases while sVEGFR1 and Ang-1 impede angiogenesis.

METHODS

Fifty-nine CR cancer patients were randomized to 7 perioperative doses of GMCSF or saline for 3days prior and 4days after CR. Blood samples were taken pre-drug (PreRx) and on several postoperative days (POD). Protein levels were assessed and PreRx and POD 5 plasma added to EC cultures after which branch point formation (ECBPF) and invasion (ECI) were measured.

RESULTS

sVEGFR1 levels were significantly higher on POD 1 and POD 5 in both groups but the GMCSF POD 5 level was twice the control value (p=0.002). Ang-2 levels were higher on PODs 1 and 5 in both groups (p<0.05) but the control POD 5 value (vs. GMCSF) was greater (p=0.03). Ang-1 decreases were noted in all (p=not significant, ns). The control group POD 5 ECBPF was 35.8% greater than Pre Rx (p=0.001) while the GMCSF result was 18.0% lower (p=ns); the control POD 5 median percent change from baseline was greater than the GMCSF result(p=0.008). The POD 5 ECI was +12.2% for the control group vs. baseline (p=ns) and -17.2% for the GMCSF group (p=ns): the control median percent change was greater than in the GMCSF group(p=0.045).

CONCLUSION

CR-related plasma changes are proangiogenic (>Ang-2) and anti-angiogenic (>sVEGFR1); the net effect is promotion of in vitro ECBPF. GMCSF limits the proangiogenic changes (higher POD 5 sVEGFR1 levels and lower Ang-2 elevations, lower POD 5 ECBPF and ECI). The clinical import of these effects is unclear; perioperative GMCSF has anti-angiogenic plasma effects that may limit tumor growth. Further investigation is warranted.

Expression of vascular endothelial growth factor expression and its relation with growth, invasion and metastasis of human colorectal cancer

AIM: To explore the relations of vascular endothelial growth factor (VEGF) expression with the growth, invasion and metastasis of colorectal cancer.

METHODS: We collected 23 fresh colorectal cancerous, distal cancerous tissues resected during operation, 16 colon polyps and 45 serum samples from colon cancer patients. The expression of VEGF in colorectal tissues and serum samples was detected by nested reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. The relationship was also analyzed between VEGF expression and Duke's staging.

RESULTS: The expression of VEGF mRNA was significantly higher in the colorectal cancer tissues than that in the distal cancerous tissues or colon polyps (65.22% vs 21.74%, 18.75%, both P < 0.01). VEGF mRNA expression was positive in 3 patients (37.5%) with Duke's stage A or B, and it was positive in 12 patients with (80.0%) stage C or D; there was significant difference between them (P < 0.05). The level of serum VEGF was markedly higher in patients with stage C or D than that in patients with stage A or B (716.71 + 229.39 ng/L vs 312.30 + 103.61 ng/L, P < 0. 01).

CONCLUSION: VEGF can serve as an index in predicting the growth, invasion and metastasis of colorectal cancer.