Major surgery increases serum levels of vascular endothelial growth factor only temporarily

Vascular Endothelial Growth Factor Levels in Serum and Plasma following Esophageal Cancer Resection - Relationship to Platelet Count

In patients with cancer circulating vascular endothelial growth factor (VEGF) may be tumor-derived and have prognostic significance. Activated platelets may also be a source of VEGF, releasing it in serum formation. Debate exists as to whether serum or plasma VEGF (S-VEGF, P-VEGF) is the most appropriate surrogate marker of tumor angiogenesis. As healing wounds produce VEGF that can spill over into the circulation, we aimed to investigate the potential confounding effects of cancer surgery on both perioperative S-VEGF and P-VEGF levels and to evaluate their relationship with platelet count. S-VEGF, P-VEGF and platelet counts were measured in 23 patients undergoing esophageal cancer resection. Samples were taken preoperatively and six weeks following surgery. Seven patients were also sampled on postoperative days 1, 5 and 10. VEGF was assayed using a commercial enzyme linked immunosorbent assay. S-VEGF and P-VEGF both rose after surgery (S-VEGF; day 5: 1017 [446–1224] pg/mL and day 10: 1231 [626–2046] pg/mL versus pre-op: 329 [189–599] pg/mL. P-VEGF; day 1: 55 [46–104] pg/mL and day 10: 58 [20–154] pg/mL versus pre-op: 23 [13–46] pg/mL), falling towards pre-operative levels by six weeks. Platelet count correlated with S-VEGF (rho=0.281; p<0.05, Spearman's rank) and P-VEGF (rho=0.330; p<0.01, Spearman's rank). Platelets may contribute to VEGF levels in plasma as well as in serum. The effects of surgery on S-VEGF or P-VEGF levels are mainly transient. Care must be exercised when interpreting circulating VEGF levels in the early postoperative period.

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.

A Switch in the Dynamics of Intra-Platelet VEGF-A from Cancer to the Later Phase of Liver Regeneration after Partial Hepatectomy in Humans

Background

Liver regeneration (LR) involves an early inductive phase characterized by the proliferation of hepatocytes, and a delayed angiogenic phase distinguished by the expansion of non-parenchymal compartment. The interest in understanding the mechanism of LR has lately shifted from the proliferation and growth of parenchymal cells to vascular remodeling during LR. Angiogenesis accompanied by LR exerts a pivotal role to accomplish the process. Vascular endothelial growth factor (VEGF) has been elucidated as the most dynamic regulator of angiogenesis. From this perspective, platelet derived/Intra-platelet (IP) VEGF-A should be associated with LR.

Material and Methods

Thirty-seven patients diagnosed with hepatocellular carcinoma and undergoing partial hepatectomy (PH) were enrolled in the study. Serum and IP VEGF-A was monitored preoperatively and at four weeks of PH. Liver volumetry was determined on computer models derived from computed tomography (CT) scan.

Results

Serum and IP VEGF-A was significantly elevated at four weeks of PH. Preoperative IP VEGF-A was higher in patients with advanced cancer and vascular invasion. Postoperative IP VEGF-A was higher after major liver resection. There was a statistically significant correlation between postoperative IP VEGF-A and the future remnant liver volume. Moreover, the soluble vascular endothelial growth factor receptor-1 (sVEGFR1) was distinctly down-regulated suggesting a fine-tuned angiogenesis at the later phase of LR.

Conclusion

IP VEGF-A is overexpressed during later phase of LR suggesting its implications in inducing angiogenesis during LR.

Serum Levels of Vascular Endothelial Growth Factor and Insulin-like Growth Factor Binding Protein-3 in Obstructive Sleep Apnea Patients: Effect of Continuous Positive Airway Pressure Treatment

Background and Aim:

Hypoxia, a major feature of obstructive sleep apnea (OSA), modifies Vascular Endothelial Growth Factor (VEGF) and Insulin-like Growth Factor Binding Protein-3 (IGFBP-3) levels, which contribute to atherogenesis and occurrence of cardiovascular (CV) events. We assessed and compared serum levels of VEGF and IGFBP-3 in newly diagnosed OSA patients and controls, to explore associations with anthropometric and sleep parameters and to study the effect of continuous positive airway pressure (CPAP) treatment on these levels.

Materials and Methods:

Serum levels of VEGF and IGFBP-3 were measured in 65 OSA patients and 31 age- and body mass index- matched controls. In OSA patients, measurements were repeated after 6 months of CPAP therapy. All participants were non-smokers, without any comorbidities or systemic medication use.

Results:

At baseline, serum VEGF levels in OSA patients were higher compared with controls (p<0.001), while IGFBP-3 levels were lower (1.41±0.56 vs. 1.61±0.38 μg/ml, p=0.039). VEGF levels correlated with apnea-hypopnea index (r=0.336, p=0.001) and oxygen desaturation index (r=0.282, p=0.007). After 6 months on CPAP treatment, VEGF levels decreased in OSA patients (p<0.001), while IGFBP-3 levels increased (p<0.001).

Conclusion:

In newly diagnosed OSA patients, serum levels of VEGF are elevated, while IGFBP-3 levels are low. After 6 months of CPAP treatment these levels change. These results may reflect an increased CV risk in untreated OSA patients, which is ameliorated after CPAP therapy.

Randomized clinical trial comparing inflammatory and angiogenic response after open versus laparoscopic curative resection for colonic cancer

BACKGROUND

Several studies have suggested that laparoscopy might confer an oncological advantage in patients undergoing surgery for colonic cancer. A decreased inflammatory and angiogenic response has been proposed. This study compared the local and systemic inflammatory and angiogenic responses after open and laparoscopic surgery for colonic cancer.

METHODS

Some 122 patients with colonic cancer were randomized to open or laparoscopic colectomy. Levels of interleukin (IL) 6 and vascular endothelial growth factor (VEGF) were measured in serum and peritoneal fluid at baseline, then at 4, 12, 24 and 48 h and on day 4 after surgery. Samples obtained on day 4 were tested in an in vitro angiogenesis assay, with measurement of number of capillaries per field and capillary length.

RESULTS

The serum IL-6 level was lower in the laparoscopic group at 4 h (mean(s.d.) 124(110) versus 244(326) pg/dl after open colectomy; P = 0·027). The serum VEGF concentration was also lower in the laparoscopic group at 48 h and day 4 (430(435) versus 650(686) pg/dl; P = 0·001). Overall, local IL-6 and VEGF levels were significantly higher than serum levels but there were no differences between groups. In vitro, postoperative serum and peritoneal fluid samples were potently angiogenic but there were no differences between open surgery and laparoscopy. Rates of tumour recurrence and survival were similar in the two groups.

CONCLUSION

Despite differences in postoperative serum levels of IL-6 and VEGF after open and laparoscopic surgery in patients with colonic cancer, the angiogenic response is comparable in both surgical approaches.

REGISTRATION NUMBER

ISRCTN55624793 (http://www.controlled-trials.com).

Systemic VEGF levels after coronary artery bypass graft surgery reflects the extent of inflammatory response

BACKGROUND

Circulating vascular endothelial growth factor (VEGF) was studied as a substitute endpoint for treatment response after VEGF plasmid therapy. The effect of coronary artery bypass surgery (CABG) with cardiopulmonary bypass (CPB) on systemic VEGF levels are however largely unknown, therefore, we studied the effect of this procedure to measure VEGF levels after surgery alone.

METHODS

Fourteen patients requiring CABG were included. VEGF165 levels, ischemic markers, and hematology were measured before, directly after six days after surgery.

RESULTS

VEGF165 in serum and whole blood levels were increased up to six days after CABG, respectively 249.6+/-50.4 to 451.7+/-56.4 (day 6) and 581.9+/-105.1 to 783.4+/-97.7 (day six). There was a close correlation of circulating VEGF165 with leukocyte counts and platelets and not with ischemic markers.

CONCLUSION

Following surgery and in case of activated leukocyte and platelet counts care must be taken in the interpretation of systemic VEGF165 levels.

Neoadjuvant treatment of colorectal cancer with bevacizumab: the perioperative angiogenic balance is sensitive to systemic thrombospondin-1 levels

PURPOSE

Colorectal cancer patients receiving neoadjuvant treatment with bevacizumab, a monoclonal antibody neutralizing vascular endothelial growth factor (VEGF), may suffer from wound healing complications after surgery as the antibody persists in patient blood. We characterized the systemic angiogenic balance in the perioperative period to evaluate its effect on physiologic angiogenesis.

EXPERIMENTAL DESIGN

Nineteen patients receiving combination chemotherapy and bevacizumab for six neoadjuvant cycles were compared with 14 patients receiving chemotherapy without bevacizumab. Plasma from perioperative days -1, +1, +7, and +21 was analyzed for VEGF, thrombospondin-1 (TSP-1), and PD-ECGF concentrations. The angiogenic capacity was further tested in an in vitro assay of endothelial cell proliferation and migration.

RESULTS

On day +1, the onset of wound healing was reflected in a change of balance, i.e., an increase of proangiogenic factors VEGF and platelet-derived endothelial cell growth factor compared with low TSP-1 inhibitor levels in both treatment groups. Patients with bevacizumab therapy showed significantly higher blood levels of total VEGF throughout the evaluation period. However, most VEGF molecules were inactive, i.e., complexed with antibody. Nevertheless, the capacity to stimulate endothelial growth was higher for these plasma samples and was reflected in low TSP-1 levels and an altered TSP-1 sensitivity. When purified TSP-1 protein was added, plasma samples of the bevacizumab but not the chemotherapy group showed reduced endothelial growth.

CONCLUSIONS

Feedback mechanisms of bevacizumab therapy are not restricted to VEGF expression but seem to involve additional factors, such as TSP-1, which influences the systemic angiogenic balance and permits endothelial growth.

Elevated vascular endothelial growth factor levels are associated with aortopulmonary collateral vessels in patients before and after the Fontan procedure

BACKGROUND

Aortopulmonary collaterals (APCs) are frequently observed before and after the Fontan procedure. However, the mechanism of the development of APCs is unknown. We hypothesized that one or several antiangiogenic and/or angiogenic growth factors might play a role in the development of APCs.

METHODS

Eighty-five patients were enrolled and divided into 3 groups (Fontan group: 30 patients after the Fontan procedure, cyanotic group: 29 patients with cyanotic heart disease, and control group: 26 patients with cyanotic heart disease after biventricular repair). We measured basic fibroblast growth factor, vascular endothelial growth factor (VEGF), hepatocyte growth factor, and endostatin at catheterization. Angiographic evaluation for the presence of APCs using a 4-point scale (grade 1: absent APCs, > or = grade 2: significantly present APCs) was performed, and the relation of the serum levels of these factors to the presence of APCs was assessed.

RESULTS

The grade of APCs significantly increased in the Fontan group, but it decreased in the control group. The serum VEGF levels were higher in the Fontan group (280 +/- 174 pg/mL) and the cyanotic group (302 +/- 245 pg/mL) than in the control group (111 +/- 91 pg/mL) (P = .0004), and they were higher in patients with APCs (383 +/- 204 pg/mL) than in those without APCs (115 +/- 65 pg/mL) (P < .0001). There was no significant difference in the serum basic fibroblast growth factor, hepatocyte growth factor, and endostatin levels between the 3 groups.

CONCLUSIONS

Aortopulmonary collaterals increase after the Fontan procedure. Serum VEGF levels are associated with the presence of APCs. Vascular endothelial growth factor may play a role in the development of APCs in patients with cyanotic heart disease and after the Fontan procedure.

Prognostic value of serum angiogenic activity in colorectal cancer patients

Angiogenesis, resulting from an imbalance between angiogenic activator factors and inhibitors, is required for tumour growth and metastasis. The determination of the circulating concentration of all angiogenic factors (activators and inhibitors) is not feasible at present. We have evaluated diagnostic and prognostic values of the measurement of serum angiogenic activity in colorectal carcinoma (CRC) patients. Serum proliferative activity (PA) on human umbilical vein endothelial cells (HUVEC) in vitro, and serum vascular endothelial growth factor (VEGF) levels were determined by ELISA in 53 patients with primary CRC, 16 subjects with non-neoplastic gastrointestinal disease (SC) and 34 healthy individuals. Data were compared with clinical outcome of the patients. Although serum from CRC patients significantly increased the PA of HUVEC, compared to culture control (HUVEC in medium + 10% foetal bovine serum (FBS); P < 0.001); our results indicate that serum PA in CRC patients was similar to that of SC or healthy individuals. There was no correlation between serum PA and circulating VEGF concentrations. Surgery produced a decrease of PA at 8 hrs after tumour resection in CRC patients compared to pre-surgery values (186 +/- 47 versus 213 +/- 41, P < 0.001). However, an increase in serum VEGF values was observed after surgery (280 [176-450] versus 251 [160-357] pg/ml, P = 0.004). Patients with lower PA values after surgery showed a worse outcome that those with higher PA values. Therefore, this study does not support a diagnostic value for serum angiogenic activity measured by proliferative activity on HUVEC but suggests it could have a prognostic value in CRC patients.

Enhanced angiogenesis following allogeneic blood transfusion

Blood transfusions are associated with recurrence of solid cancers. Angiogenesis is essential for cancer growth. Our aim was to determine for the first time in a prospective cohort study the effect of prestorage allogeneic leucodepleted SAGM (saline, adenine, glucose, mannitol) red cell transfusion on angiogenic factor levels and in vitro angiogenesis. Forty pretransfusion adult hospital inpatients were selected consecutively. Serum vascular endothelial growth factor (VEGF) and endostatin were measured in each patient before and after prestorage allogeneic leucodepleted SAGM red cell transfusion. All samples were exposed to an in vitro endothelial cell proliferation assay and 10 sample groups were also exposed to an in vitro whole angiogenesis assay. The median number of units transfused was 2 (minimum-maximum, 2-4). Twenty-nine (73%) patients had a rise in VEGF, with an overall increase of 118 pg/ml (quartiles -5, 306; P < 0.01). Twenty-eight (70%) patients had a decrease in endostatin, with an overall reduction of 1.2 ng/ml (quartiles 4.0, 0.0; P = 0.017). There was an overall 33% increase in endothelial cell proliferation (P < 0.01) and a 9.4% increase in in vitro whole assay angiogenesis (P < 0.01). Prestorage allogeneic leucodepleted SAGM red cell transfusions are associated with a favourable angiogenic factor imbalance and an elevation in in vitro angiogenesis.

Expression of plasma vascular endothelial growth factor in patients with hepatocellular carcinoma and effect of transcatheter arterial chemoembolization therapy on plasma vascular endothelial growth factor level

AIM: To investigate the expression level of plasma vascular endothelial growth factor (P-VEGF) in patients with hepatocellular carcinoma (HCC) and its relationship with the clinicopathologic characteristics, and to examine the changes of P-VEGF in the course of transcatheter arterial chemoembolization (TACE).

METHODS: Peripheral blood samples were taken from 45 HCC patients before and 1, 3, 7 d, and 1 mo after TACE. Plasma VEGF level was measured with the quantitative sandwich enzyme-linked immunosorbent assay (ELISA). Twenty patients with benign liver lesions and 17 healthy control subjects were also included in this study.

RESULTS: Plasma VEGF levels in HCC patients were significantly elevated as compared to those in patients with benign liver lesions (P = 0.006) and in the normal controls (P = 0.003). Significant differences were observed when P-VEGF was categorized by tumor size (P = 0.006), portal vein thrombosis (P = 0.011), distant metastasis (P = 0.017), arterial-portal vein shunting (P = 0.026), and International Union Against Cancer (UICC) TNM stage (P = 0.044). There was no correlation between plasma level of VEGF and the level of alpha fetoprotein (α-FP) (r = 0.068, P = 0.658) and weakly correlated with the number of platelets (r = 0.312, P = 0.038). P-VEGF levels increased significantly and reached the peak value on the first day after TACE, and then decreased gradually. The change rate of P-VEGF concentration (one month post-TACE/pre-TACE × 100%) was correlated with the retention rate of lipiodol oil (rs = 0.494, P = 0.001) and the tumor volume change (rs = 0.340, P = 0.034). The patients who achieved a partial or complete response to TACE therapy showed significantly less pre-treatment P-VEGF than those nonresponders (P = 0.025). A high pre-therapeutic P-VEGF level was associated with poor response to treatment (P = 0.018).

CONCLUSION: A high pre-treatment P-VEGF level is a useful marker for tumor progression, especially for vascular invasion. TACE increases the level of P-VEGF only temporarily which may be associated with tumor ischemia. P-VEGF may be useful in predicting treatment response, monitoring disease course after TACE and judging the effect of different TACE regimens.

Effects of high intensity focused ultrasound on vascular endothelial growth factor in melanoma bearing mice

This study was to investigate the effects of high intensity focused ultrasound on vascular endothelial growth factor. A B16 melanoma model was adopted in our study. Melanoma bearing mice were randomly divided into two groups: HIFU group and surgery group. While the control group was only injected with isovolumetric normal saline solution and treated as the surgery group. We detected VEGF both in tissues and sera through immunohistochemical method and ELISA respectively. Tissues were sampled pre- and at the 3rd day post-operation in HIFU group and blood samples were taken pre- and at the 1st, 3rd, and 7th day post-operation in all the groups. As a result, in the tissues, VEGF was expressed in 80% melanomas, but none was detected in the targeted area after HIFU treatment. In the sera, there was a decreasing tendency of serum-VEGF concentrations in group HIFU and surgery after operation, while that in the control group increased after operation. The levels in the HIFU group on day 1, 3, and 7 postoperatively were all lower than that in the surgery group respectively (79.16 pg/ml vs 91.59 pg/ml; 33.64 pg/ml vs 49.39 pg/ml; 30.37 pg/ml vs 46.68 pg/ml), but there wasn't any significant difference (P > 0.05). So HIFU can destroy VEGF in the targeted area and maybe have less of an effect on serum-VEGF than surgery.

Surgery and angiogenesis

Surgery may be regarded as an angiogenesis-inducing condition since it evokes the release of many angiogenic factors. Regarding the mechanistic overlap between tumor-associated neovascularisation and (physiological) angiogenesis in response to injury and hypoxia, surgery may promote the uncontrolled growth of residual dormant tumor cells. With the advent of anti-angiogenic agents, surgeons will be faced with more patients undergoing surgery for primary and secondary tumors under anti-angiogenic treatment. This could present problems with regard to angiogenesis-dependent phenomena such as wound repair, healing of intestinal anastomoses and liver regeneration. In this review we will discuss these matters from a biomedical and clinical point of view.

Radical prostatectomy lowers plasma vascular endothelial growth factor levels in patients with prostate cancer

OBJECTIVES

To measure the change in plasma vascular endothelial growth factor (VEGF) levels after radical prostatectomy (RP) and to examine the association of pre-RP VEGF levels with known prognostic factors.

METHODS

Plasma was collected from patients in two separate cohorts. The first cohort included 86 patients who consented to give blood before and after RP. The second cohort consisted of 280 plasma samples, obtained from untreated patients with clinically localized prostate cancer. Plasma VEGF levels were measured by enzyme-linked immunosorbent assay. The change in plasma VEGF before and 6 to 8 weeks after RP was analyzed using a Wilcoxon signed rank test. The associations between the pre-RP VEGF levels and prognostic factors were assessed with the Spearman correlation coefficient and the Kruskal-Wallis test.

RESULTS

In a cohort of 86 patients with clinically localized prostate cancer, the median preoperative VEGF level was 49.8 pg/mL. The median level 1 month after surgery was significantly lower at 39.1 pg/mL (P = 0.006, 20% decrease). A repeat analysis 6 months or more after surgery demonstrated that the percentage of decrease in the plasma VEGF levels persisted. Plasma VEGF levels were also measured in a separate cohort of 280 patients with localized prostate cancer and demonstrated no statistically significant association with risk groups or known tumor-associated prognostic factors.

CONCLUSIONS

These results suggest that the prostate gland itself may be a significant source of systemic VEGF and raises the possibility that elevated plasma VEGF levels could be a reflection of prostatic VEGF production.

Interleukin-6 and Tumor Necrosis Factor-α in Patients with Obstructive Sleep Apnea-Hypopnea Syndrome

BACKGROUND

In previous studies, significantly elevated levels of vascular endothelial growth factor (VEGF) have been reported in patients with severe obstructive sleep apnea-hypopnea syndrome (OSAHS). On the other hand, plasma tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) have been significantly higher in mild sleep apneics than in normal controls. However, this study included a small number of patients and milder cases of OSAHS.

OBJECTIVES AND METHODS

To assess the involvement of IL-6 and TNF-alpha in VEGF increases in patients with severe OSAHS, serum levels of IL-6 and TNF-alpha were determined in patients with severe OSAHS (n=110) and compared to those of controls (n=45) using an enzyme-linked immunosorbent assay.

RESULTS

No significant increase in IL-6 or TNF-alpha was detected in the present study cohort. However, the body mass index was significantly correlated with the severity of the apnea-hypopnea index.

CONCLUSIONS

These data suggest that the elevation in VEGF is not directly related to IL-6 or TNF-alpha levels. However, the question of whether VEGF is the cause or the result of OSAHS remains to be determined. Further studies are needed to clarify the role of IL-6 and TNF-alpha in the pathogenesis of OSAHS, in which obesity should be entered as an independent factor.

Effects of major liver resection, with or without recombinant bactericidal/permeability-increasing protein (rBPI21), on the angiogenic profile of patients with metastatic colorectal carcinoma

BACKGROUND

Surgery induces a process of wound healing, which has immunological and angiogenic aspects. Bactericidal/permeability-increasing protein (BPI) is found in azurophilic granules of human neutrophils, which is bactericidal and neutralizes lipo-polysaccharide (LPS). This may reduce postoperative infectious complications. In addition, BPI has been shown to be an inhibitor of angiogenesis.

METHODS

A total of 18 patients with metastasized colorectal carcinoma to the liver were double blind randomized. The levels of the pro-angiogenic factors interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) and the angiogenesis inhibitor endostatin were investigated after liver surgery with perioperative administration of either rBPI(21) or placebo.

RESULTS

The highest IL-6 levels were found during the first 24 hr and reached peak levels already at 2 hr postoperatively in both groups. In both groups VEGF levels decreased sharply in the postoperative hours, returning to baseline levels in the days afterwards. In both groups, an immediate decrease in endostatin levels was observed which remained significantly low. RBPI(21) transiently influenced IL-6 and VEGF.

CONCLUSIONS

RBPI(21) only marginally affected IL-6 and VEGF levels. Surgery per se induced an immediate immune response (IL-6) and an immediate angiogenic response, reflected in an initial VEGF decrease and a longer lasting decrease of endostatin. These findings demonstrate the dynamics of tissue responses in the first phase of wound healing.

Preoperative and perioperative chemotherapy with 5-fluorouracil as continuous infusion in operable breast cancer expressing a high proliferation fraction: cytotoxic treatment during the surgical phase

BACKGROUND

Experimental data on perioperative chemotherapy (PeCT) indicate that its initiation might be most useful if administered as close as possible to the time of first 'disturbance of the tumour'. Regimens including 5-fluorouracil (5-FU) as continuous infusion are commonly used in the preoperative setting, especially for large tumours and locally advanced disease. We therefore evaluated the role of PeCT with 5-FU as continuous infusion after preoperative chemotherapy (PreCT), covering the surgical phase and acute wound healing period, in patients with breast cancer too large to attempt breast-conserving surgery upon diagnosis.

PATIENTS AND METHODS

Breast cancer patients, clinical stages T2-T3, N0-N2, M0, and Ki-67 labelling index >/= 20%, were treated every 3 weeks with a maximum of six courses of vinorelbine 20 mg total dose intravenously (i.v.) on days 1 and 3, cisplatin 60 mg/ m(2) i.v. on day 1 and 5-FU 200 mg/m(2)/day as a continuous infusion (ViFuP regimen). Patients who achieved a clinical and radiological objective remission with PreCT were also treated with perioperative 5-FU that was continued until 30 min before, and restarted immediately after surgery, prolonging infusion until 15 days after surgery.

RESULTS

Following preoperative treatment, 39 of 49 evaluable patients [80%; 95% confidence interval (CI) 70% to 90%] had an objective response. Pathological complete remission (pCR) was achieved in 14 (29%) patients. No relevant clinical or haematological toxicity due to PeCT was observed. In 36 patients submitted to PeCT the rate of pCR was 33% (95% CI 18% to 48%). The highest response of the primary tumour to PreCT and PeCT was observed in women with tumours not expressing estrogen and progesterone receptors (pCR 46%; 95% CI 19% to 73%).

CONCLUSIONS

Preoperative therapy can be protracted into the surgical (and wound healing) period without significant additional short-term toxicity. Proper selection of patients according to biological features might improve the therapeutic yield of preoperative therapies.

A critical review of vascular endothelial growth factor (VEGF) analysis in peripheral blood: is the current literature meaningful?

Vascular endothelial growth factor (VEGF) is a potent angiogenic growth factor with a key role in many physiological and pathological processes. Investigation into the implications of circulating levels of this cytokine is progressing at an exponential rate. However, there are important inconsistencies between reports ranging from method of sample collection, processing, software manipulation and data interpretation and controversy as to whether plasma, serum or whole blood will provide the best prognostic information. Different techniques of centrifugation and temperature on sample handling and the impact of in vitro collection of blood on subsequent VEGF results have not been fully appreciated. We provide a critical review of the literature, report the results of our further investigations, suggest a uniform protocol for handling blood samples and highlight previously unsuspected problems in data interpretation.