Microvessel quantification and its possible relation with liver metastasis in colorectal cancer

Identification of high-risk factors for recurrence of colon cancer following complete mesocolic excision: An 8-year retrospective study

BACKGROUND

Colon cancer recurrence is a common adverse outcome for patients after complete mesocolic excision (CME) and greatly affects the near-term and long-term prognosis of patients. This study aimed to develop a machine learning model that can identify high-risk factors before, during, and after surgery, and predict the occurrence of postoperative colon cancer recurrence.

METHODS

The study included 1187 patients with colon cancer, including 110 patients who had recurrent colon cancer. The researchers collected 44 characteristic variables, including patient demographic characteristics, basic medical history, preoperative examination information, type of surgery, and intraoperative information. Four machine learning algorithms, namely extreme gradient boosting (XGBoost), random forest (RF), support vector machine (SVM), and k-nearest neighbor algorithm (KNN), were used to construct the model. The researchers evaluated the model using the k-fold cross-validation method, ROC curve, calibration curve, decision curve analysis (DCA), and external validation.

RESULTS

Among the four prediction models, the XGBoost algorithm performed the best. The ROC curve results showed that the AUC value of XGBoost was 0.962 in the training set and 0.952 in the validation set, indicating high prediction accuracy. The XGBoost model was stable during internal validation using the k-fold cross-validation method. The calibration curve demonstrated high predictive ability of the XGBoost model. The DCA curve showed that patients who received interventional treatment had a higher benefit rate under the XGBoost model. The external validation set's AUC value was 0.91, indicating good extrapolation of the XGBoost prediction model.

CONCLUSION

The XGBoost machine learning algorithm-based prediction model for colon cancer recurrence has high prediction accuracy and clinical utility.

Identification of high-risk factors associated with mortality at 1-, 3-, and 5-year intervals in gastric cancer patients undergoing radical surgery and immunotherapy: an 8-year multicenter retrospective analysis

Background

Combining immunotherapy with surgical intervention is a prevailing and radical therapeutic strategy for individuals afflicted with gastric carcinoma; nonetheless, certain patients exhibit unfavorable prognoses even subsequent to this treatment regimen. This research endeavors to devise a machine learning algorithm to recognize risk factors with a high probability of inducing mortality among patients diagnosed with gastric cancer, both prior to and during their course of treatment.

Methods

Within the purview of this investigation, a cohort of 1015 individuals with gastric cancer were incorporated, and 39 variables encompassing diverse features were recorded. To construct the models, we employed three distinct machine learning algorithms, specifically extreme gradient boosting (XGBoost), random forest (RF), and k-nearest neighbor algorithm (KNN). The models were subjected to internal validation through employment of the k-fold cross-validation technique, and subsequently, an external dataset was utilized to externally validate the models.

Results

In comparison to other machine learning algorithms employed, the XGBoost algorithm demonstrated superior predictive capacity regarding the risk factors that affect mortality after combination therapy in gastric cancer patients for a duration of one year, three years, and five years posttreatment. The common risk factors that significantly impacted patient survival during the aforementioned time intervals were identified as advanced age, tumor invasion, tumor lymph node metastasis, tumor peripheral nerve invasion (PNI), multiple tumors, tumor size, carcinoembryonic antigen (CEA) level, carbohydrate antigen 125 (CA125) level, carbohydrate antigen 72-4 (CA72-4) level, and H. pylori infection.

Conclusion

The XGBoost algorithm can assist clinicians in identifying pivotal prognostic factors that are of clinical significance and can contribute toward individualized patient monitoring and management.

Nestin Expression as a Diagnostic and Prognostic Marker in Colorectal Cancer and Other Tumors

Lung cancer, colon cancer, breast cancer, and prostate cancer are the leading causes of death in developed countries. Many cancers display non-specific signs in the early stage of the disease, thus making early diagnosis often difficult. We focused on nestin as a new biomarker of possible clinical importance in the early diagnosis and monitoring of cancer. The expression of nestin takes place at an early stage of neural differentiation, but no expression of the nestin gene can be revealed in normal, mature adult tissues. Nestin plays an important role in the development of the central nervous system and contributes to the organization and maintenance of cell shape. Nestin was found to be a marker of microvessel density, which in turn has proven to be a reliable prognostic factor for neoplastic malignancies in patients. Nestin expression correlates with an increased aggressiveness of tumor cells. The role of nestin in cancers of the colon and rectum, liver, central nervous system, lung cancer, breast cancer, melanoma, and other cancers has been reviewed in the literature. Associations between nestin expression and prognosis or drug-resistance may help in disease management. More research is needed to understand the molecular mechanisms of nestin expression and its role in possible targeted therapy.

P53 expression and micro-vessel density in relation with 5-year survival in patients with colorectal cancer

Colorectal cancers are among the commonest causes of cancer related morbidity and mortality worldwide. Adenomatous polyps which develop dysplastic changes are the main cause of invasive cancer. P53 inactivation is a key genetic step in the occurrence of cancer. The degree of the formation of the blood vessels inside the tumor (microvessel density) increases the ability of the tumor to have local infiltration, metastatic potential and may reflect the tumor metabolic activity. A total number of 104 patients who underwent surgeries for colorectal adenocarcinoma followed for 5 years. Patients were categorized into 4 categories based on tumor expression of P53 and micro-vessel density, 64.42% of patients were females, 58.7% died from colorectal cancer during the 5-year period, 37.5% had 5-years survival free from cancer, and 16.3% survived with recurrence, 28.8% had over expression of both P53 and MVD. A significant correlation was found between: P53 and MVD with the site of tumor occurrence being more significant with left-sided colonic tumors, the clinical stage being more significant with stage III disease, and with the survival rate being more significant in patients who died during this period, P values 0.025, 0.01, and 0.001 respectively. Overexpression of P53 and MVD are associated with higher mortality and more advanced disease. We advise a more aggressive form of therapy for colorectal adenocarcinomas expressing high level of both factors and tumors with high expression of both factors may need modification in the chemotherapeutic drugs or radiation therapy with closer follow up than tumors having lower expression.

Antitumor and anti-angiogenic effects of artemisinin on breast tumor xenografts in nude mice

Breast cancer is a high incidence disease in humans. Artemisinin is an important extract that is widely used as an antimalarial drug which also serve as effective treatments for cancer. 32 nude mice were injected with 0.2 ml of MDA-MB-231 cell suspension of 2 × 10⁷ cells/ml respectively. The nude mice models were randomly divided into four groups of 8 in each group. Each group was given daily gavage, high dose group: 200 mg/kg/0.1 ml, middle dose group 100 mg/kg/0.1 ml, low dose group 50 mg/kg/0.1 ml, control group: 0.1 ml vegetable oil was fed continuously for 21 days. ELISA was used to detect serum vascular endothelial growth the content of factor VEGF and hypoxia-inducible factor HIF-1α were detected. The expression of Notch pathway-related factors in tumor tissue was detected by fluorescence quantitative assay. ELISA results showed that the serum VEGF decreased significantly in the high dose group compared with the control group (p < .01), while the other dose groups did not have significant (p > .05). The serum HIF-1α in the high dose group compared with the control group, the decrease in HIF-1α was significant (p < .05), and the other groups were not significant (p > .05). The result of fluorescence quantitative section showed that artemisinin could down-regulate the expression of notch signaling related factors notch1, Dll4 and Jagged1, and 200 mg/kg dose group had the most significant effect. It may inhibit the development of tumors by reducing serum angiogenesis-related factors VEGF, HIF-1ɑ and inhibiting the activity of notch1 signaling pathway related factors.

Chitinase 3-Like 1, Nestin, and Testin Proteins as Novel Biomarkers of Potential Clinical Use in Colorectal Cancer: A Review

Colorectal cancer is the third most commonly diagnosed cancer in males and the second most common in females. Only 10-20% of patients are diagnosed at the early stage of disease. Recently, the role of novel biomarkers of the neoplastic process in the early detection of colorectal cancer has been widely discussed. In this review, we focused on the three novel biomarkers that are of potential clinical importance in diagnosing and monitoring colorectal cancer. Chitinase 3-like 1 protein, also known as YKL-40, and nestin and testin proteins are produced by colorectal cancer cells. YKL-40 protein is a marker of proliferation, differentiation, and tissue morphogenetic changes. The level of YKL-40 is elevated in about 20% of patients with colorectal cancer. An increased expression of nestin indicates immaturity. It is a marker of angiogenesis in neoplastic processes. Testin protein is a component of cell-cell connections and focal adhesions. The protein is produced in normal human tissues, but not in tumor tissues. Downregulation of testin increases cell motility, spread, and proliferation, and decreases apoptosis. The usefulness and role of these biomarkers, both alone and combined, in the diagnostics of colorectal cancer should be further explored as early cancer detection may substantially improve treatment outcome and patient survival.

Correlations between CD34 Immunolabelled Blood Vessels and CD34 mRNA Expression in Colorectal Cancer

Purpose: This study aims to determine the correlation between microvessel density of CD34 immunolabelled blood vessels and CD34 mRNA gene expression in colorectal cancer tissue. Material/Methods: Standard immunohistochemistry and gene expression was perform on samples collected from 76 patients with colorectal cancer in order to determinate the number of CD34 immunolabelled blood vessels and the relative quantity of CD34 mRNA. Results: For the study group, the mean CD34 immunolabelled microvascular density (MVD) was of 307/mm², and the mean CD34 gene expression value for colon cancer was 2.303. The low p value (<0.001) of the Spearman correlation test showed a significant direct correlation between CD34 MVD and CD34 gene expression for the entire study group. Conclusions: CD34 gene`s expression can be looked at as a prognostic factor in colorectal cancer.

Evaluation of Endoglin (CD105) expression in pediatric rhabdomyosarcoma

BACKGROUND

The Intratumoral Microvessel Density (IMVD) is commonly used to quantify tumoral vascularization and is usually assessed by pan-endothelial markers, such as CD31. Endoglin (CD105) is a protein predominantly expressed in proliferating endothelium and the IMVD determined by this marker measures specifically the neovascularization. In this study, we investigated the CD105 expression in pediatric rhabdomyosarcoma and assessed the neovascularization by using the angiogenic ratio IMVD-CD105 to IMVD-CD31.

METHODS

Paraffin-embedded archival tumor specimens were selected from 65 pediatric patients affected by rhabdomyosarcoma. The expression levels of CD105, CD31 and Vascular Endothelial Growth Factor (VEGF) were investigated in 30 cases (18 embryonal and 12 alveolar) available for this study. The IMVD-CD105 to IMVD-CD31 expression ratio was correlated with clinical and pathologic features of these patients.

RESULTS

We found a specific expression of endoglin (CD105) in endothelial cells of all the rhabdomyosarcoma specimens analyzed. We observed a significant positive correlation between the IMVD individually measured by CD105 and CD31. The CD105/CD31 expression ratio was significantly higher in patients with lower survival and embryonal histology. Indeed, patients with a CD105/CD31 expression ratio < 1.3 had a significantly increased OS (88%, 95%CI, 60%-97%) compared to patients with higher values (40%, 95%CI, 12%-67%). We did not find any statistical correlation among VEGF and EFS, OS and CD105/CD31 expression ratio.

CONCLUSION

CD105 is expressed on endothelial cells of rhabdomyosarcoma and represent a useful tool to quantify neovascularization in this tumor. If confirmed by further studies, these results will indicate that CD105 is a potential target for combined therapies in rhabdomyosarcoma.

Coexpression of COX-2 and iNOS in Angiogenesis of Superficial Esophageal Squamous Cell Carcinoma

Using immunohistochemical staining, the present study was conducted to examine whether cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) affect angiogenesis in early-stage esophageal squamous cell carcinoma (ESCC). We also analyzed the correlation between these two factors. Cyclooxygenase 2, iNOS, and angiogenesis in early-stage ESCC are unclear. Using 10 samples of normal squamous epithelium, 7 samples of low-grade intraepithelial neoplasia (LGIN), and 45 samples of superficial esophageal cancer, we observed the expression of COX-2 and iNOS. We then investigated the COX-2 and iNOS immunoreactivity scores and the correlation between COX-2 or iNOS scores and microvessel density (MVD) using CD34 or CD105. The intensity of COX-2 or iNOS expression differed significantly according to histological type (P < 0.001). The scores of COX-2 and iNOS were lowest for normal squamous epithelium, followed in ascending order by LGIN, carcinoma in situ and tumor invading the lamina propria mucosae (M1-M2 cancer); and tumor invading the muscularis mucosa (M3) or deeper cancer. The differences were significant (P < 0.001). Cancers classified M1-M2 (P < 0.01 and P < 0.05, respectively); M3; or deeper cancer (P < 0.01) had significantly higher COX-2 and iNOS scores than normal squamous epithelium. There was a significant correlation between COX-2 and iNOS scores (P < 0.001, rs = 0.51). Correlations between COX-2 score and CD34-positive MVD or CD105-positive MVD were significant (rs = 0.53, P < 0.001; rs = 0.62, P < 0.001, respectively). Inducible nitric oxide synthase score was also significantly correlated with CD34 MVD and CD105 MVD (rs = 0.45, P < 0.001; rs = 0.60, P < 0.001, respectively). Chemoprevention of COX-2 or iNOS activity may blunt the development of ESCC from precancerous lesions.

A randomized phase II study of capecitabine-based chemoradiation with or without bevacizumab in resectable locally advanced rectal cancer: clinical and biological features

BACKGROUND

Perioperatory chemoradiotherapy (CRT) improves local control and survival in patients with locally advanced rectal cancer (LARC). The objective of the current study was to evaluate the addition of bevacizumab (BEV) to preoperative capecitabine (CAP)-based CRT in LARC, and to explore biomarkers for downstaging.

METHODS

Patients (pts) were randomized to receive 5 weeks of radiotherapy 45 Gy/25 fractions with concurrent CAP 825 mg/m(2) twice daily 5 days per week and BEV 5 mg/kg once every 2 weeks (3 doses) (arm A), or the same schedule without BEV (arm B). The primary end point was pathologic complete response (ypCR: ypT0N0).

RESULTS

Ninety pts were included in arm A (44) or arm B (46). Grade 3-4 treatment-related toxicity rates were 16% and 13%, respectively. All patients but one (arm A) proceeded to surgery. The ypCR rate was 16% in arm A and 11% in arm B (p =0.54). Fifty-nine percent vs 39% of pts achieved T-downstaging (arm A vs arm B; p =0.04). Serial samples for biomarker analyses were obtained for 50 out of 90 randomized pts (arm A/B: 22/28). Plasma angiopoietin-2 (Ang-2) levels decreased in arm A and increased in arm B (p <0.05 at all time points). Decrease in Ang-2 levels from baseline to day 57 was significantly associated with tumor downstaging (p =0.02).

CONCLUSIONS

The addition of BEV to CAP-based preoperative CRT has shown to be feasible in LARC. The association between decreasing Ang-2 levels and tumor downstaging should be further validated in customized studies.

TRIAL REGISTRY

Clinicaltrials.gov identifier NCT01043484. Trial registration date: 12/30/2009.

Can vascular endothelial growth factor and microvessel density be used as prognostic biomarkers for colorectal cancer? A systematic review and meta-analysis

Background. Vascular endothelial growth factor (VEGF) and microvessel density (MVD) are associated with greater incidence of metastases and decreased survival. Whether they can be used as prognostic indicators of colorectal cancer (CRC) is still controversial. Methods. The authors performed a meta-analysis using the results of a literature search of databases of PubMed and EMBASE, and the references of articles included in the analysis. Meta-analysis was performed using random effects model and hazard ratios (HRs) and 95% confidence intervals (CIs) as effect measures. Results. Twenty studies contributed to the analysis of VEGF, of which 16 were used for overall survival (OS) and 9 for disease-free survival (DFS). High VEGF levels has a relationship with unfavorable survival (OS: HR = 1.98, 95% CI: 1.30–3.02; DFS: HR = 2.10, 95% CI: 1.26–3.49) and a 4.22-fold increase in the rate of distant metastases. Analysis was performed on 18 studies for MVD; the results showed that patients with high MVD expression in tumors appeared to have poorer overall survival (HR = 1.39, 95% CI: 1.22–1.58) and were at a greater risk of having unfavorable clinical characteristics related to prognosis. Corresponding results were obtained from quantitative and/or qualitative analysis of clinicopathological. Conclusions. The meta-analysis demonstrates that VEGF and MVD can be used as prognostic biomarkers for CRC patients.

[Microenvironment and colorectal liver metastases angiogenesis: surgical implications]

Stephen Paget's proposed an original "seed and soil" theory, with organ-preference patterns of tumor metastasis resulting in interaction between metastatic tumor cells and their specific microenvironment. There is many experimental and clinical data showing that this theory is validated. More recently, it has been suggested that early changes in the microenvironment at the distant sites, could be induced by the primary tumor, reported as "pre-metastatic niche" formation. Tumor cells could produce growth factors, cytokines which could facilitate the recruitment and the mobilization of the bone marrow-derived endothelial progenitor cells, and thus necessary for the tumor neovascularization and metastasis growth. Although the clinical value of the concept of the premetastatic niche is not yet elucidated, these data could encourage surgeons to perform the colorectal surgery first and then the liver surgery, in patients with synchronous colorectal liver metastases. The reciprocal interactions between primary tumor and microenvironment at the distant sites are therefore determinant for tumor progression. Taken together, the microenvironment is an important therapeutic target and surgeons and oncologist could discuss the choice of different surgical strategy for patient with synchronous colorectal liver metastases regarding the interaction with the microenvironment affected by primary tumor resection.

Nestin: A novel angiogenesis marker and possible target for tumor angiogenesis

Abnormal vasculature, termed tumor vessels, is a hallmark of solid tumors. The degree of angiogenesis is associated with tumor aggressiveness and clinical outcome. Therefore, exact quantification of tumor vessels is useful to evaluate prognosis. Furthermore, selective detection of newly formed tumor vessels within cancer tissues using specific markers raises the possibility of molecular targeted therapy via the inhibition of tumor angiogenesis. Nestin, an intermediate filament protein, is reportedly expressed in repair processes, various neoplasms, and proliferating vascular endothelial cells. Nestin expression is detected in endothelial cells of embryonic capillaries, capillaries of the corpus luteum, which replenishes itself by angiogenesis, and proliferating endothelial progenitor cells, but not in mature endothelial cells. Therefore, expression of nestin is relatively limited to proliferating vascular endothelial cells and endothelial progenitor cells. Nestin expression is also reported in blood vessels within glioblastoma, prostate cancer, colorectal cancer, and pancreatic cancer, and its expression is more specific for newly formed blood vessels than other endothelial cell markers. Nestin-positive blood vessels form smaller vessels with high proliferation activity in tumors. Knockdown of nestin in vascular endothelial cells suppresses endothelial cell growth and tumor formation ability of pancreatic cancers in vivo. Using nestin to more accurately evaluate microvessel density in cancer specimens may be a novel prognostic indicator. Furthermore, nestin-targeted therapy may suppress tumor proliferation via inhibition of angiogenesis in numerous malignancies, including pancreatic cancer. In this review article, we focus on nestin as a novel angiogenesis marker and possible therapeutic target via inhibition of tumor angiogenesis.

Brain metastases from colorectal cancer: microenvironment and molecular mechanisms

Colorectal cancer is one of the most common digestive tract malignancies in the world. Owing to the newer and more effective systemic therapies, the life of colorectal cancer patients can be remarkably prolonged, and the incidence of brain metastases is increasing. However, little is known about the underlying mechanisms of brain metastasis from colorectal cancer. Here we review the tumor microenvironment and metastasis associated molecules in brain metastases from colorectal cancer. A further understanding of these mechanisms will help us to propose better strategies for colorectal cancer patients with brain metastasis and improve their life quality.

Role of CD34, vascular endothelial growth factor, and p53 in neoangiogenesis as correlated with stage of disease in colorectal carcinoma

BACKGROUND

Angiogenesis is critical for the growth of colorectal carcinoma (CRC). Vascular endothelial growth factor is the most important angiogenic growth factor.

METHOD

Fifty cases of CRC operated at INHS Asvini were studied by using immunohistochemical labelling of the tumours by using CD34, p53, and vascular endothelial growth factor (VEGF).

RESULTS

Out of the 50 cases, 31 (62%) were positive for p53; of which 80.7% showed high expression. Significant staining (> 20% tumour cells showing positivity) was seen in 33 patients (66%), while 34% were negative. Of the 33 positive cases, 57.58% showed high-grade VEGF positivity.

CONCLUSION

Vascular endothelial growth factor correlated significantly with the stage and grade of disease. Intra tumours microvessel density as calculated from CD34 expression increased with the stage and grade of the CRC.

Hypoxia-inducible factor-1alpha and -2alpha are expressed in most rectal cancers but only hypoxia-inducible factor-1alpha is associated with prognosis

The hypoxia-mediated response of tumours is a major determining factor in growth and metastasis. Understanding tumour biology under hypoxic conditions is crucial for the development of antiangiogenic therapy. Using one of the largest cohorts of rectal adenocarcinomas to date, this study investigated hypoxia-inducible factor-1α (HIF-1α) and HIF-2α protein expression in relation to rectal cancer recurrence and cancer-specific survival. Patients (n=90) who had undergone surgery for rectal adenocarcinoma, with no prior neoadjuvant therapy or metastatic disease, and for whom adequate follow-up data were available were selected. Microvessel density (MVD), HIF-1α and HIF-2α expressions were assessed immunohistologically with the CD34 antibody for vessel identification and the NB100-131B and NB100-132D3 antibodies for HIF-1α and HIF-2α, respectively. In a multifactorial analysis, results were correlated with tumour stage, recurrence rate and long-term survival. Microvessel density was higher across T and N stages (P<0.001) and associated with poor survival (hazard ratio (HR)=8.7, P<0.005) and decreased disease-free survival (HR=4.7, P<0.005). hypoxia-inducible factor-1α and -2α were expressed in >50% of rectal cancers (HIF-1α, 54%, 48/90; HIF-2α, 64%, 58/90). HIF-1α positivity was associated with both TNM stage (P<0.05) and vascular invasion (P<0.005). In contrast, no associations were shown between HIF-2α expression and any pathological features, and HIF-1α positivity had no effect on outcome. The study showed an independent association between HIF-1α expression and advanced TNM stage with poor outcome. Our results indicate that HIF-1α, but not HIF-2α, might be used as a marker of prognosis, in addition to methods currently used, to enhance patient management.

Modification of the primary tumor microenvironment by transforming growth factor alpha-epidermal growth factor receptor signaling promotes metastasis in an orthotopic colon cancer model

The transforming growth factor alpha (TGFalpha)/epidermal growth factor receptor (EGFR) signaling pathway appears to play a critical role in colon cancer progression, but the cellular and molecular mechanisms that contribute to metastasis remain unknown. KM12C colon cancer cell clones expressing high (C9) or negligible (C10) levels of TGFalpha were implanted into the cecal walls of nude mice. C9 tumors formed autocrine and paracrine EGFR networks, whereas C10 tumors were unable to signal through EGFR. The tumor microenvironment of C9, but not C10, contained cells enriched in vascular endothelial growth factor (VEGF) A, interleukin-8, and matrix metalloproteinases-2 and -9 and had a high vascular surface area. C9 tumors recruited a macrophage population that co-expressed F4/80 and lymphatic vessel endothelial hyaluronic acid receptor and produced VEGFC. The mean lymphatic density of C9 tumors was threefold higher than that of C10 tumors. C9, but not C10, tumor cells metastasized to regional lymph nodes in all mice and to the liver in 5 of 10 mice. Forced expression of TGFalpha in C10 tumor cells led to the generation of autocrine and paracrine EGFR signaling, macrophage recruitment, enhanced blood and lymphatic vascular surface areas, and increased lymphatic metastasis. Collectively, these data show that activation of TGFalpha-EGFR signaling in colon cancer cells creates a microenvironment that is conducive for metastasis, providing a rationale for efforts to inhibit EGFR signaling in TGFalpha-positive colon cancers.

Targeted therapy in colorectal carcinoma: more than a theory

OBJECTIVE

The aim of this review was to examine clinical trial data reporting the use of targeted therapies in colorectal cancer.

METHOD

Candidate trials were identified by a comprehensive literature search.

RESULTS

The data on the use of targeted therapies; usually combined with chemotherapy in the treatment of colorectal cancer is accumulating rapidly. These new agents will increasingly become incorporated into standard treatment schedules.

CONCLUSION

Targeted therapy has moved rapidly from the laboratory to the clinic and is opening up potentially new and exciting areas for the development of the systemic treatment of colorectal cancer.

Exploiting novel molecular targets in gastrointestinal cancers

Novel molecular targets are being discovered as we learn more about the aberrant processes underlying various cancers. Efforts to translate this knowledge are starting to impact on the care of patients with gastrointestinal cancers. The epidermal growth factor receptor (EGFR) pathway and angiogenesis have been targeted successfully in colorectal cancer with cetuximab, panitunumab and bevacizumab. Similarly, EGFR-targeting with erlotinib yielded significant survival benefit in pancreatic cancer when combined with gemcitabine. The multi-targeting approach with sorafenib has made it the first agent to achieve significant survival benefit in hepatocellular carcinoma. Efforts to exploit the dysregulated Akt/mTOR pathway in GI cancer therapy are ongoing. These molecular targets can be disrupted by various approaches, including the use of monoclonal antibody to intercept extracellular ligands and disrupt receptor-ligand binding, and small molecule inhibitors that interrupt the activation of intracellular kinases.

[Assessment of angiogenesis expression and its relationship with prognosis of colorectal cancer by conventional and computer-assisted histopathological image analysis]

PURPOSE

To quantify the degree of angiogenesis by conventional method (microvessel density, MVD) and computerized method (endothelial area, EA), and to evaluate their relationships with the prognosis of patients operated on for colorectal adenocarcinoma.

METHODS

Tumoral angiogenesis was studied by means of an immunohistochemical technique, using CD 34, on 126 patients; to quantify the angiogenesis, MVD (defined as number of microvessels per mm(2)) and EA measurement (defined as the area occupied by EA in the microscope field). A computerized method, IMAGELab software was utilized to quantify endothelial area.

RESULTS

The mean number of microvessels was 128.6 MV/mm(2) (SD = 44.5) and the mean EA was 4.3% (SD = 2.1). The Pearson method demonstrated a low correlation coefficient between MVD and EA (r = 0.429). No relationship between MVD and EA was observed with regard to relapse-free interval and overall survival.

CONCLUSION

The histological analysis of angiogenesis expression in patients with colorectal adenocarcinoma can be performed either by computer-assisted image analysis of endothelial area or by conventional microvessels counting. Both methods did not show any significant relationship between these angiogenesis parameters with relapse-free interval and overall survival.

Angiogenesis in colorectal cancer: prognostic and therapeutic implications

Angiogenesis is important for tumor growth and metastasis. This account reviews the clinicopathological studies conducted in the field of angiogenesis in colorectal cancer, the methods of assessing vascular-related characteristics in tissue sections and provides a background for the usefulness of antiangiogenic policies along with chemotherapy and radiotherapy. Highly angiogenic colorectal tumors are associated with aggressive histopathological features and poor patients' survival. Similarly, factors stimulating angiogenesis, such as vascular endothelial growth factor (VEGF), thymidine phosphorylase (TP), and others, are commonly related to increased vascular density (VD) and, therefore, to an unfavorable clinical course. Anti-VEGF agents have improved prognosis in patients with metastatic colorectal cancer, when added to standard chemotherapy. It is expected that, in addition to adjuvant chemotherapy and radiotherapy, agents blocking the stimulatory effect of VEGF on endothelial cells would prove beneficial to the patient.

Microvessel density and VEGF expression are prognostic factors in colorectal cancer. Meta-analysis of the literature

We performed a meta-analysis of all published studies relating intratumoural microvessel density (MVD) (45 studies) or vascular endothelial growth factor (VEGF) expression (27 studies), both reflecting angiogenesis, to relapse free (RFS) and overall survival (OS) in colorectal cancer (CRC). For each study, MVD impact was measured by risk ratio between the two survival distributions with median MVD as cutoff. Eleven studies did not mention survival data or fit inclusion criteria, six were multiple publications of same series, leaving 32 independent studies for MVD (3496 patients) and 18 for VEGF (2050 patients). Microvessel density was assessed by immunohistochemistry, using antibodies against factor VIII (16 studies), CD31 (10 studies) or CD34 (seven studies). Vascular endothelial growth factor expression was mostly assessed by immunohistochemistry. Statistics were performed for MVD in 22 studies (the others lacking survival statistics) including nine studies (n = 957) for RFS and 18 for OS (n = 2383) and for VEGF in 17 studies, including nine studies for RFS (n = 1064) and 10 for OS (n = 1301). High MVD significantly predicted poor RFS (RR = 2.32 95% CI: 1.39-3.90; P < 0.001) and OS (RR = 1.44; 95% CI: 1.08-1.92; P = 0.01). Using CD31 or CD34, MVD was inversely related to survival, whereas it was not using factor VIII. Vascular endothelial growth factor expression significantly predicted poor RFS (RR = 2.84; 95% CI: 1.95-4.16) and OS (RR=1.65; 95% CI: 1.27-2.14). To strengthen our findings, future prospective studies should explore the relation between MVD or VEGF expression and survival or response to therapy (e.g. antiangiogenic therapy). Assessment of these angiogenic markers should be better standardised in future studies.

ADVANCES IN THE ADJUVANT TREATMENT OF COLORECTAL CANCER

BACKGROUND

There have been numerous advances in the adjuvant therapy of colon cancer in the last two decades.

METHODS

This review outlines the historical perspectives of adjuvant treatment as well as current and emerging standards of care.

RESULTS

Although previous regimens included a variety of equivalent schedules of 5-fluorouracil and folinic acid, integration of newer drugs such as oxaliplatin are offering significant improvements in disease-free survival. The use of targeted agents such as bevacuzimab creates the potential to further increase cure rates in the adjuvant setting. The current low rate of referral of eligible patients for chemotherapy in Australia is also discussed.

CONCLUSION

Adjuvant therapy for colon cancer is making major strides as we attempt to cure more patients.

The intratumoral microvessel density and expression of bFGF and nm23-H1 in colorectal cancer

It has previously been reported that intratumoral microvessel density (IMD), and the expression of bFGF and nm23-H1 are useful prognostic markers in colorectal cancer (CRC). In this study, a total of 100 CRCs were evaluated histopathologically, and IMD, bFGF and nm23-H1 expression were assessed by immunohistochemistry. IMD of patients increased with grade and stage, and this increase was statistically significant (p<0.05). A significantly higher incidence of high bFGF expression scores was also associated with increasing grade and stage (p<0.05). However, there was no significant difference between the grades in nm23-H1 expression (p=0.234). nm23-H1 expression occurred with lower incidence in stages C1, C2 and D than in stages B1 and B2 (p<0.05). Thus, a negative correlation was found between nm23-H1 expression and stage or lymph node metastasis (LNM) (p<0.05). IMD and bFGF expression were positively correlated with grade, stage, LNM, and lymphovascular invasion. Although positive correlation was found between IMD and bFGF, nm23-H1 expression negatively correlated with both of them. As a result, in clinical practice, increased IMD and bFGF expression and decreased nm23-H1 expression may provide valuable information in characterizing the malignant phenotype.

Absence of smooth muscle actin-positive pericyte coverage of tumor vessels correlates with hematogenous metastasis and prognosis of colorectal cancer patients

OBJECTIVES

Immature microvessels, which are not covered by pericytes, are irregular and leaky. We hypothesized that tumor cells can penetrate immature microvessels more easily than mature microvessels. In this study, we investigated the maturation of angiogenesis by the immunohistochemical staining of colorectal cancer specimens and determined the correlation between the microvessel count or the maturity of microvessels and clinicopathological variables.

METHODS

Ninety-two surgical specimens from our department were used. Double immunostaining of endothelial cells with anti-CD34 antibody and pericytes with anti-alpha-smooth muscle actin antibody was performed. The microvessel density (MVD) and microvessel pericyte coverage index (MPI) as an index of microvessel maturation were evaluated.

RESULTS

The MVD showed a significant positive correlation with tumor size, depth of invasion and Dukes' stage. The MPI showed a significant positive correlation with the histological differentiation of the tumor tissues and distant metastasis at the time of operation. The high MVD group (> or =26.0, n = 50) tended to have a poorer prognosis than the low MVD group (<26.0, n = 42) (p = 0.097). Next, the 50 patients in the high MVD group were classified into two subgroups of high MPI (> or =78.1%, n = 25) and low MPI (<78.1%, n = 25). MPI showed a significant negative correlation with hematogenous metastasis, and the low MPI group demonstrated a significantly poorer survival than the high MPI group (p = 0.040).

CONCLUSIONS

These findings demonstrate that immature neovascularization was observed in poorly differentiated tumors and was correlated with metastasis, resulting in a poorer prognosis. Taken together, not only microvessel density but also vascular maturation were crucial factors for colorectal cancer patients.

Interaction between morphology and angiogenesis in human early colorectal cancers

Morphologically, early colorectal cancers are divided into two types: polypoid cancers and non-polypoid cancers. They vary in growth pattern, progression, and genetic alteration. Angiogenesis between polypoid and non-polypoid cancers may also be different. Therefore, the present study aims to evaluate angiogenesis in the early stages of colorectal malignancy, with particular attention to the morphological differences. The serial slides of all materials (48 polypoid cancers, 10 non-polypoid cancers, 20 adenomas and 10 normal tissues) were immunohistochemically stained for three endothelial cell markers (CD31, von Willebrand factor and CD105), counted for the number of microvessels in the same hot spots, and the angiogenic status was estimated. Polypoid cancers had higher microvessel counts and were more predominantly supplied by activated (CD105-positive, newly forming) microvessels than non-polypoid cancers. The present study indicated the possibility that the difference in growth pattern might be explained by the difference in angiogenesis between polypoid and non-polypoid cancers.

Prognostic relevance of tumour-associated macrophages and von Willebrand factor-positive microvessels in colorectal cancer

Tumour-associated macrophages (TAM) are involved in tumour angiogenesis and anti-tumour immune response. In colorectal cancer (CRC), an association of high microvascular density (MVD) and unfavourable prognosis has been reported by some investigators. However, heterogeneous patient groups were studied. We, therefore, analysed the correlation between TAM and MVD and the prognostic relevance of MVD, TAM and T lymphocyte infiltration for long-term survival in a homogeneous group of 70 patients with moderately differentiated cancers of the International Union Against Cancer (UICC) stages II and III, who did not receive chemotherapy. MVD was evaluated using immunohistochemistry with antibodies against CD34 and von Willebrand factor (vWF). TAM and T lymphocytes were visualised with antibodies against CD68 and CD3, respectively. Statistical analysis did not reveal a significant correlation between TAM and T lymphocyte numbers and MVD. Multivariate analysis of immunohistochemical data from all CRC patients and the subgroup of patients with UICC stage-II CRC identified TAM- and vWF-positive microvessel numbers as prognostically relevant markers. Low numbers of TAM- and high numbers of vWF-positive microvessels were associated with an unfavourable prognosis. In conclusion, TAM- and vWF-positive microvessel numbers may serve as independent prognostic markers for patients with UICC stage-II and -III CRC and may help to identify patients with an unfavourable prognosis.

Inhibitory Effects of Artesunate on Angiogenesis and on Expressions of Vascular Endothelial Growth Factor and VEGF Receptor KDR/flk-1

Artesunate (ART) is a semi-synthetic derivative of artemisinin extracted from the plant Artemisia annua is a safe and effective antimalarial drug. In the present investigation, ART was found also to inhibit angiogenesis in vivo and in vitro. The anti-angiogenic effect in vivo was evaluated in nude mice by means of human ovarian cancer HO-8910 implantation and immunohistochemical stainings for microvessel (CD(31)), vascular endothelial growth factor (VEGF) and VEGF receptor KDR/flk-1. Tumor growth was decreased and microvessel density was reduced following drug treatment with no apparent toxicity to the animals. ART also remarkably lowered VEGF expression on tumor cells and KDR/flk-1 expression on endothelial cells as well as tumor cells. The in vitro effect of ART was tested on models of angiogenesis, namely, proliferation, migration and tube formation of human umbilical vein endothelial cells (HUVEC). The results showed that ART significantly inhibited angiogenesis in a dose-dependent form in the range of 0.5 approximately 50 micromol/l. Additionally, the inhibitory effect of ART on HVUEC proliferation was stronger than that on Hela, JAR, HO-8910 cancer cells, NIH-3T3 fibroblast cells and human endometrial cells, indicating that ART was selectively against HUVEC. These findings and the known low toxicity of ART are clues that ART may be a promising angiogenesis inhibitor.

The subserosal elastic lamina: an anatomic landmark for stratifying pT3 colorectal cancer

PURPOSE

Approximately 50 percent of all patients with resected colorectal carcinoma have tumors with pT3 status; however, no subclassifications of the penetration depth have been proposed. The purpose of this study is to evaluate the significance of histologic invasion beyond subserosal elastic lamina by colorectal carcinoma for postoperative recurrence and long-term survival after resection.

METHODS

pT3 colorectal carcinomas located above the peritoneal reflection were retrospectively classified into two depth grades (subserosal elastic lamina classification). Namely, "pT3-shallow" is defined as tumors those are confined above the subserosal elastic lamina, and "pT3-deep" is defined as tumors those penetrate beyond it. Based on subserosal elastic lamina classification, the 325 consecutive patients who underwent resections were divided into two groups, and then the clinicopathologic features, incidence of postoperative recurrence, and survival rates were compared between the two groups.

RESULTS

The overall postoperative recurrence rate in the pT3-deep group (35.2 percent) was higher than that in the pT3-shallow group (20.8 percent). In detail, liver and peritoneal recurrence rates in the pT3-deep group (19.7 percent, 7.7 percent, respectively) were higher than those in the pT3-shallow group (9.4 percent, 2.0 percent, respectively). There was a strong difference ( P < 0.0001) in overall survival rate between the pT3-deep group (5-year survival of 57.0 percent) and the pT3-shallow group (5-year survival of 78.6 percent). Multivariate analysis revealed that synchronous hematogenous metastasis ( P < 0.0001), lymph node metastasis ( P < 0.05), venous invasion ( P < 0.01), and subserosal elastic lamina classification ( P < 0.05) were the independent prognostic factors for postoperative survival.

CONCLUSIONS

The newly proposed subserosal elastic lamina classification is a useful subclassification to predict the prognosis of patients with resected pT3 colorectal carcinomas.

Endoglin (CD105) and vascular endothelial growth factor as prognostic markers in colorectal cancer

Endoglin (CD105) has been shown to be a more useful marker to identify proliferating endothelium involved in tumor angiogenesis than panendothelial markers such as CD31. We investigated endoglin and vascular endothelial growth factor expression as possible prognostic markers in colorectal cancer. Surgical specimens from 150 patients with resected colorectal carcinomas were immunostained for endoglin, CD31 and vascular endothelial growth factor. Colorectal carcinoma cases consisted of 50 cases without lymph node metastases, 50 cases with only lymph node metastases and 50 cases with liver metastases (38 cases also had positive lymph nodes). Positively stained microvessels were counted in densely vascular foci (hot spots) at x 400 fields in each specimen. For vascular endothelial growth factor, intensity of staining was scored on a three-tiered scale. Results were correlated with other prognostic parameters. Endoglin demonstrated significantly more proliferating neoplastic microvessels than CD31 (31+/-10 vs 19+/-8/0.15 mm2 field, P<0.001). Low vascular endothelial growth factor expression within tumor cells was seen in 49 (33%) and high expression in 101 cases (67%). There was a positive correlation of endoglin, CD31 counts and vascular endothelial growth factor overexpression with the presence of angiolymphatic invasion and lymph node metastases (P<0.05). Only endoglin counts correlated significantly with liver metastases and positive vascular pedicle lymph nodes (P<0.05), while vascular endothelial growth factor showed significant correlation with the depth of invasion (P<0.01). Endoglin, by staining higher numbers of the proliferating vessels in colon carcinoma, is a more specific and sensitive marker for tumor angiogenesis than the commonly used panendothelial markers. Endoglin staining also showed prognostic significance with positive correlation with angiolymphatic invasion and metastases to lymph nodes and liver.

Angiogenesis and dendritic cell density are not correlated with metachronous distant metastasis in curatively operated rectal cancer

BACKGROUND AND AIMS

Apart from surgery, treatment of rectal cancer increasingly involves the use of (neo-)adjuvant strategies. To optimize the selection process for these therapy regimens, especially in the field of cellular and molecular biology, new prognostic factors additional to the established TNM system are being investigated.

PATIENTS AND METHODS

Two groups of patients ( n=2x85) with rectal carcinoma curatively treated by surgery alone were studied retrospectively (median follow-up 6.1 years). To exclude the effect of the surgeon only patients free of locally recurrent disease were selected. Patient groups were matched for age, gender, UICC stage, and year of operation (1982-1991) and differed only in subsequent metachronous distant metastatic spread, i.e., the criterion to be studied. The factors investigated in uni- and multivariate analysis were angiogenesis, density of dendritic cells, grading, venous invasion, and lymphatic invasion.

RESULTS

Grading invariably proved to be the only significant prognostic factor. In univariate analysis the absence of venous invasion was also correlated significantly with increased disease-free survival.

CONCLUSION

Angiogenesis and dendritic cell density are not prognostic factors for metachronous distant metastasis in rectal cancer and therefore cannot serve as selection parameters for adjuvant therapy.

Microvessel densities and microvascular architecture in colorectal carcinomas and their liver metastases: significant correlation of high microvessel densities with better survival

AIMS

Microvessel densities in cancers have been shown to be a prognostic factor for some types of cancer. For colorectal cancer, however, the situation is far from clear.

METHODS

A consecutive series of 173 colorectal carcinomas was investigated, and to these were added 55 liver metastases originating from colorectal cancer. Microvessels were counted in hotspots (factor VIII immunostaining, 0.74 mm2). The capillary architecture was scored according to the degree of order and envelopment of the neoplastic glands. Endothelial proliferation was determined by factor VIII/Ki67 double labelling.

RESULTS

Mean microvessel densities were 51.8 for colorectal carcinomas (range 8-140) and 31.9 for liver metastases (range 3-101). Stratification according to stage, depth of infiltration and nodal involvement showed a significant inverse relation with increase. Mean microvessel densities in primaries were significantly higher than in metastases. Kaplan-Meier analysis showed a significantly higher cancer-specific survival for high microvessel densities (median as cut-off) and for a more ordered microvascular architecture. Endothelial proliferation in carcinomas was significantly higher than in normal mucosa.

CONCLUSIONS

Contrary to other types of cancer, for colorectal cancer high microvessel densities confer good rather than poor prognosis. We hypothesize that neoangiogenesis, though extant in colorectal cancer, is not rate-limiting in the metastatic cascade.

Increase in podoplanin-expressing intestinal lymphatic vessels in inflammatory bowel disease

Ulcerative colitis (UC) and Crohn's disease (CD) are two presentations of inflammatory bowel diseases (IBDs). Whereas the inflammation in UC is confined to the mucosa/submucosa, CD is considered a transmural disease with characteristic lymphoid aggregates with or without epithelioid granulomas in the subserosa. Here we examined and quantified the distribution of lymphatic capillaries in small- and large-bowel resection specimens (non-IBD n=8; CD n=20 and UC n=13) using immunohistochemical staining with anti-human podoplanin antibody, an established marker for lymphatic endothelium. In normal small intestine, the lymphatic network originated in the capillaries beneath the surface epithelial cells, whereas it started in the lower third of the mucosa of the large intestine. Lymphatic microvessel counts revealed a statistically highly significant increase ( P<0.005 in the muscularis mucosae, P=0.012 in the tunica submucosa and P=0.012 in the tunica subserosa) in IBDs when compared with normal intestine. Numerical differences between CD and UC samples were not significant. Prominence of lymphatic capillaries could also be observed in areas where fibrosis replaced chronic inflammation. These findings suggested that lymph-vessel proliferation in IBDs may be triggered by chronic inflammation irrespective of its organization and is maintained in fibrotic end-stage disease.

Phase II, randomized trial comparing bevacizumab plus fluorouracil (FU)/leucovorin (LV) with FU/LV alone in patients with metastatic colorectal cancer

PURPOSE

This phase II trial investigated the safety and efficacy of two doses of bevacizumab, a monoclonal antibody to vascular endothelial growth factor, plus fluorouracil (FU)/leucovorin (LV) versus FU/LV alone in patients with metastatic colorectal cancer.

PATIENTS AND METHODS

One hundred four previously untreated patients with measurable metastatic colorectal cancer were randomly assigned to one of the following three treatment groups: 36 to FU (500 mg/m(2))/LV (500 mg/m(2)) alone, 35 to FU/LV + low-dose bevacizumab (5 mg/kg every 2 weeks), and 33 to FU/LV + high-dose bevacizumab (10 mg/kg every 2 weeks). FU/LV was given weekly for the first 6 weeks of each 8-week cycle.

RESULTS

Compared with the FU/LV control arm, treatment with bevacizumab (at both dose levels) plus FU/LV resulted in higher response rates (control arm, 17%, 95% confidence interval [CI], 7% to 34%; low-dose arm, 40%, 95% CI, 24% to 58%; high-dose arm, 24%, 95% CI, 12% to 43%), longer median time to disease progression (control arm, 5.2 months, 95% CI, 3.5 to 5.6 months; low-dose arm, 9.0 months, 95% CI, 5.8 to 10.9 months; high-dose arm, 7.2 months, 95% CI, 3.8 to 9.2 months), and longer median survival (control arm, 13.8 months; 95% CI, 9.1 to 23.0 months; low-dose arm, 21.5 months, 95% CI, 17.3 to undetermined; high-dose arm, 16.1 months; 95% CI, 11.0 to 20.7 months). After cross-over, two of 22 patients had a partial response to bevacizumab alone. Thrombosis was the most significant adverse event and was fatal in one patient. Hypertension, proteinuria, and epistaxis were other potential safety concerns.

CONCLUSION

The encouraging results of this randomized trial support further study of bevacizumab 5 mg/kg plus chemotherapy as first-line therapy for metastatic colorectal cancer.

Microvessel morphology and vascular endothelial growth factor expression in human colonic carcinoma with or without metastasis

We quantified microvessel morphology and vascular endothelial growth factor (VEGF) expression in human colonic carcinoma with or without metastasis. The cancerous growth and the noncancerous section of surgical specimens from 36 patients with colorectal carcinoma (14 without metastasis and 22 with metastasis) were studied. Tissue slices immunostained with CD34 were processed for microvessel counts (per mm(2)), the mean diameter of microvessels (microm), and the mean spatial direction of microvessels (degree), defined by the angle between the longitudinal axis of microvessels and the direction perpendicular to the surface of the mucosa. Tissue slices immunostained with anti-VEGF antibody were processed for total epithelial cell counts (per mm(2)), VEGF-positive cell counts (per mm(2)), and VEGF-positive ratio (%). Carcinoma without metastasis had significantly larger microvessel counts (213 +/- 77, p < 0.01), larger microvessel diameter (7.99 +/- 1.77, p < 0.05), and larger spatial direction (47.2 +/- 8.3, p < 0.01) than normal tissue (144 +/- 49 for microvessel counts; 7.03 +/- 0.90 for microvessel diameter; 39.5 +/- 6.6 for spatial direction). Compared with carcinoma without metastasis, carcinoma with metastasis had a significantly larger microvessel diameter (9.75 +/- 2.65, p < 0.03) and lower microvessel counts (180 +/- 92, p = 0.51). Carcinoma without metastasis had a significantly larger VEGF-positive cell count (1276 +/- 805, p < 0.05) and larger VEGF-positive ratio (53.6 +/- 39.3, p < 0.05) than normal tissue (571 +/- 553 for VEGF-positive cell counts; 24.6 +/- 23.2 for VEGF-positive ratio). Carcinoma with metastasis had a significantly lower total cell count (1443 +/- 237, p < 0.001) and lower VEGF-positive cell count (716 +/- 463, p < 0.05) than carcinoma without metastasis. With tumor progression, microvessel diameter significantly increased and microvessel counts decreased, which can be in part explained by VEGF expression. The microvessel diameter seems to be the dominant parameter responsible for cancer cell intravasation as the first step of metastasis.

Tumor growth patterns and biological characteristics of early gastric carcinoma

Gastric cancer is a major malignant disease. The development of new diagnostic techniques and mass screening have led to increased detection rates of patients with early-stage gastric cancer in Japan. However, after curative resection of early gastric cancer, there are various types of recurrences, and residual occult disease and distant micrometastasis precede death. The growth and metastatic potential of cancer cells are closely related to the postoperative outcome, and patients at risk for cancer-related death after surgery have to be closely monitored to prevent tumor recurrence. The biological behavior of cancer cells should be determined in patients with early gastric cancer and with a less favorable prognosis to detect potential early recurrences in the liver. Two types of growth patterns have been found in early gastric cancer: the superficially spreading (Super) type and the penetrating (Pen) type, and the clinicopathological and biological characteristics of each type have been extensively determined. A subtype of the Pen-type gastric cancer, which is progressing expansively with complete destruction of the muscularis mucosae (Pen A type) has a less favorable prognosis due to early recurrences in the liver. These clinical cancer types are closely related to chromosomal instability in DNA aneuploidy and p53 overexpression, and vascular endothelial growth factor activation induced tumor angiogenesis, vascular invasion and hematogenous metastasis. Thus, patients with Pen-A-type cancer showing expansive tumor growth had a poorer postoperative outcome and a hematogenous-related recurrence of the cancer. Antiangiogenic approaches in a postoperative setting may prove to be effective in preventing tumor recurrence and improving the prognosis for these patients.

Angiogenesis in advanced colorectal adenocarcinoma with special reference to tumoral invasion

BACKGROUND

Angiogenesis is a crucial step in tumor growth and progression. Its quantification by microvessel counting has a prognostic value in several types of malignancies and recently has been appraised in gastrointestinal tumors.

AIM

To assess the prognostic significance of microvessel quantification in colorectal carcinomas, studying its association with hematogenous metastases, survival and clinicopathological variables such as size, histologic differentiation and depth of tumoral invasion.

PATIENTS/METHODS

Forty eight patients with colorectal adenocarcinoma were included in this study. Histologic sections of invasion tumoral margin (4 microns) were analyzed and endothelined microvessels were immunostained with monoclonal mouse Von Willebrand Factor (anti-FVIII). The microvessel count was performed from the identification of the area with increased microvessel density--hot spots--and results of the mean in five of these fields.

RESULTS

The cut-off microvessel count was 14 microvessels/0.785 mm2, which divided the sample into hypovascular and hypervascular groups. While 2/8 (25%) tumors with muscularis propria invasion were classified as hypervascular, 11/15 (73%) tumors with serosa or perivisceral fat were classified as hypervascular. However, a non-significant statistical association was found between the angiogenesis quantification, hematogenous metastases, survival and clinicopathological variables such as size and histologic differentiation of the tumor.

CONCLUSIONS

The findings of significantly increase of microvessel count in conformity with tumoral invasion depth supports the hypothesis that tumor progression might be related to angiogenesis. Although angiogenesis is an important step in the tumoral growth and during the metastatization process, other factors can be implicated.

Morphologic analysis of microvessels in colorectal tumors with respect to the formation of liver metastases

BACKGROUND AND OBJECTIVES

Overexpression of VEGF and proliferation of microvessels are strongly related to liver metastases, however, morphologic analyses of microvessels in liver metastases have not been reported. The purpose of the present study was to examine the correlation between liver metastases and the diameters of microvessel lumens in the tumor tissue.

METHODS

Fifty-nine patients with liver metastases from colorectal cancers and 112 patients who underwent curative colorectal resection and survived without any recurrence were reviewed. Microvessel density (MVD) and the diameters of the lumens of individual microvessels were assessed.

RESULTS

There was a significant difference in terms of the mean MVD of primary tumors between patients with liver metastases and those without liver metastases. The numbers of patients with liver metastases who had microvessels 100-200 microm in diameter and microvessels more than 200 microm in diameter were significantly greater than patients without liver metastases. Microvessels with lumens more than 100 microm in diameter were not detected in the liver metastatic lesion.

CONCLUSION

Large microvessels in the primary tumor favor intravasation of cancer cells.

Angiogenesis at the site of deepest penetration predicts lymph node metastasis of submucosal colorectal cancer

PURPOSE

Intratumor microvessel count has been reported as a useful prognostic factor in patients with cancer of various organs. This study was undertaken to clarify the relation between microvessel count and lymph node metastasis in submucosal colorectal cancer.

METHODS

Microvessel count was estimated in 254 invasive tumors that had been resected from patients with submucosal colorectal cancer. Immunohistochemistry with antibodies against CD34 was performed on archival specimens, and microvessel counts were estimated based on the average count of three fields (original magnification, x400) in the most vascular area at the site of deepest submucosal penetration.

RESULTS

Microvessel count ranged from 10 to 98, with a median of 40. Lesions with high microvessel counts (> or =40) had a significantly higher incidence of lymph node metastasis than those with low microvessel counts (<40; 21.8 percent vs. 6.2 percent). None of the 79 lesions with low microvessel counts and submucosal invasion up to a depth of 1,500 microm had metastasized to the lymph nodes. In multivariate analysis, microvessel count was an independent risk factor for lymph node metastasis in submucosal colorectal cancer (P = 0.0026).

CONCLUSION

Microvessel count at the site of deepest submucosal penetration can be one of the most useful predictors for lymph node metastasis. Analysis that combines microvessel count and depth of submucosal invasion may predict the occurrence of lesions without lymph node metastasis.

Morphometric study of tumor angiogenesis as a new prognostic factor in nasopharyngeal carcinoma patients

The aim of this study was to determine the possible prognostic significance of tumor angiogenesis (TA) in nasopharyngeal carcinoma (NPC) patients. Fifty-five NPC patients were evaluated in relation to survival. Endothelial cells were immunohistochemically stained with anti-von Willebrand factor (F-VIII), CD-31 and CD-34 antibodies, and microvessels counted in the most active areas of tumor neovascularization or hotspotsusing both a manual and an automatic method. Overall survival analysis calculated by the Kaplan Meiertest revealed that both methods were correlated with a statistical significance between intratumoral microvessel density (IMD) and overall survival, using either manual (p=0.0141) or automatic counting (p=0.0117). Other angiogenic parameters studied were perimeter, roundness and accumulative area of the microvessels using a morphometric analyzer. Moreover, our results show that cases with high IMD demonstrated a prognostic significance in relation to the accumulative area (p=0.0072).

Vascular endothelial growth factor-C (VEGF-C) expression in human colorectal cancer tissues

Vascular endothelial growth factor-C (VEGF-C) functions specifically to induce lymphangiogenesis. We examined the relationship between expression of VEGF-C and clinicopathological features in patients with colorectal cancer. The expression of VEGF-C in the 99 primary tumours and 18 metastatic lymph nodes from colorectal cancer patients was examined immunohistochemically. To verify VEGF-C mRNA expression, reverse transcriptase-polymerase chain reaction (RT-PCR) was carried out. The expression of VEGF-C correlated with lymphatic involvement, lymph nodes metastasis, and depth of invasion. On the other hand, correlations were nil with regard to gender of the patients, histologic type, venous involvement, and liver metastasis. The expression of VEGF-C in metastatic lymph nodes was fairly consistent with this expression in the primary tumour. Survival time was shorter for VEGF-C positive groups than for VEGF-C negative ones, but with no statistically significant difference. RT-PCR findings revealed that the expression of VEGF-C mRNA correlated mostly with that of VEGF-C protein expression. VEGF-C may play an important role in lymphatic spread of colorectal cancer.

Prognostic and predictive value of intratumoral microvessels density in operable non-small-cell lung cancer

Experimental evidence suggests that tumor growth and progression depend on angiogenesis. In a retrospective study we evaluated the relationship between tumor angiogenesis and survival in patients with NSCLC treated with potentially curative surgery between 1992 and 1997. The study population consisted of 76 patients. An anti-CD34 monoclonal antibody was used to measure angiogenesis in tumor samples. Angiogenesis was quantified in terms of microvessel count (MVC): in each sample the three most intense regions of neovascularization were identified under low microscopic power. A x250 field in each of the three areas was then counted and the highest count of the three fields was recorded. Disease free (DFS) and overall survival (OS) during follow up were evaluated. Gender, age, stage, histologic type and KI-67 were the other factors considered for analysis. The median MVC in our series was 41.5. Among the clinicopathologic parameters examined the microvessel count was the only one to show a significant association with disease free survival in univariate analysis (P = 0.04). MVC value is a new indicator of tumor aggressiveness in patients with NSCLC who underwent potentially curative surgery and should be taken into consideration in selecting patients for adjuvant treatment.

Prospective study of intratumoral microvessel density, p53 expression and survival in colorectal cancer

Adjuvant treatment of patients with colorectal cancer is hampered by a lack of reliable prognostic factors in addition to the clinicopathological staging system. A poorly defined but considerable fraction of Astler-Coller stage B patients will experience tumour recurrence, and some of the stage C patients will probably survive for a prolonged time after surgery without adjuvant treatment. Assessing parameters related to tumour angiogenesis has provided valuable prognostic information in different tumour types. The formation of new microvessels is part of the malignant phenotype in the majority of tumours. Alterations in tumour-suppressor genes, such as the p53 gene, or oncogenes, such as the ras gene, have been found to be responsible for changing the local balance of pro- and antiangiogenic factors in favour of the former. In this prospective study, intratumoral microvessel density (IMD) was assessed by immunostaining tissue sections for CD31 and counting individual microvessels in selected and highly vascular regions in specimens of 145 colorectal cancer patients. p53 protein overexpression was semiquantitatively determined after immunohistochemistry. In both uni- and multivariate analysis, high IMD was significantly associated with shorter survival in the patients undergoing surgery with curative intent (Astler-Coller stages A-C). p53 added prognostic power to IMD, both in Astler-Coller stage B and stage C patients. An association between IMD and mode of metastasis was also noted. High IMD was strongly associated with the incidence of haematogenous metastasis during follow-up, but not with the presence of lymphogenic metastasis observed at surgery. This study confirms the results of previous retrospective analyses of IMD and survival in colorectal cancer and warrants a clinical validation by randomizing stage B tumour patients with high IMD and p53 overexpression between adjuvant treatment or not.

Tumor angiogenesis as a prognostic predictor in colorectal carcinoma with special reference to mode of metastasis and recurrence

Tumor angiogenesis has proved to be a useful prognostic determinant for patients with various solid tumors. In this study, we investigated the quantitative expression of angiogenesis in colorectal carcinoma to determine how angiogenesis correlates with clinicopathologic factors and prognosis. One hundred twenty-seven specimens resected from patients with primary colorectal carcinoma were investigated immunohistochemically using a polyclonal antibody against factor-VIII-related antigen, and areas with the highest vascular density at the invasive tumor margin were counted at 200 times magnification. The microvessel count, defined as angiogenesis density (AD), became significantly higher with increase in histologic grade (p = 0.02) and Dukes stage (p = 0.001). AD was also significantly higher in patients with lymph node metastasis (p = 0. 005), lymphatic invasion (p = 0.042), vascular invasion (p < 0.001), and liver metastasis (p = 0.0004) than in those without. In addition, patients with synchronous distant hematogenous metastasis in stage D disease showed significantly higher AD than patients with nonhematogenous metastasis (p = 0.006). When 27 cases of disease recurrence after surgical resection with curative intent were stratified according to mode of spread, AD in cases with a hematogenous pattern of relapse proved to be significantly higher than in cases with nonhematogenous spread (p < 0.001). No significant differences were, however, found in AD when they were subdivided as to operative nodal status (p = 0.39 and 0.08 in the node-negative and the node-positive group, respectively). Multivariate analysis indicated that AD was an independent prognostic factor (p = 0.0004) in colorectal carcinoma. Quantitative evaluation of tumor angiogenesis at the invasive tumor margin is suggested to be a good prognostic indicator and a useful predictor for hematogenous spread and recurrence in patients with colorectal carcinoma.

Interstitial collagenase and the ED-B oncofetal domain of fibronectin are markers of angiogenesis in human skin tumors

Collagenase-1 (C1) is the predominant matrix metalloproteinase present in newly formed microvessels and serves as a marker of neovascularization. The expression of the oncofetal fragment of fibronectin (Fn-f) was found to be increased during angiogenesis. In the present study, we investigated the relationship between the expression of collagenase-1 and the oncofetal fragment of fibronectin in newly formed microvessels as markers of tumor angiogenesis. In aggressive skin tumors (i.e., morpheaform and recurrent basal cell carcinomas) and squamous cell carcinomas, neovascularization was associated with a marked increase in the number of C1-positive and Fn-f-positive microvessels. At the beginning of elongation, microvessels begin to produce C1 but lose their ability to express type IV collagen and FVIII-related antigen. Later, this endothelium produces both Fn-f and C1. As maturation of microvessels occurs, C1-containing endothelium fails to express Fn-f but begins to produce a type IV collagen-containing basement membrane and FVIII-related antigen. These studies show that there is a selective expression of both Fn-f and collagenase by immature endothelial cells. C1 production begins at early stages of blood vessel formation and continues throughout angiogenesis. In contrast, Fn-f expression is limited to later stages of vasculogenesis, indicating that these proteins are reliable markers of angiogenesis.