The correlation of angiogenesis with metastasis in primary cutaneous melanoma: a comparative analysis of microvessel density, expression of vascular endothelial growth factor and basic fibroblastic growth factor

AIM: To establish whether there is a correlation between angiogenesis and metastasis in primary cutaneous melanoma (PCMM). METHODS: We studied the microvessel density and the expression of vascular endothelial growth factor (VEGF) and basic fibroblastic growth factor (bFGF) in 22 cases of PCMM with metastasis at presentation (metastatic group) and 28 cases of PCMM without metastasis for 24 months or more (non-metastatic group). Microvessels were stained with CD31/PECAM-1 antibody and counted. We assessed the proportion of VEGF expression in tumour cells, lymphocytes infiltrating the tumour (TIL) and lymphocytes at the periphery of the tumour, as well as the proportion of bFGF expression in tumour cell cytoplasms, nuclei and intra- and peritumoral vessels. RESULTS: An increased microvessel density was detected in the metastatic group (15-33 [24.09 +/- 5.55] versus 2-24 [12.96 +/- 6.02]). Moreover, enhanced expression of VEGF in tumour cells and peritumoral lymphocytes (Chi-square p = 0.038 and p = 0.018) and bFGF in peritumoral vessels (chi(2) p = 0.013) correlated with the simultaneous presence of melanoma metastasis in PCMM. Furthermore, microvessel density was correlated with the expression of bFGF in peritumoral vessels (rs = 0.53, p = 0.049) and VEGF in tumour cells (rs = 0.37, p = 0.019). CONCLUSION: Microvessel density as well as the expression of both VEGF and bFGF might be informative concerning the progression of melanoma.     

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.     

Endoglin (CD105) and vascular endothelial growth factor as prognostic markers in prostatic adenocarcinoma

We studied endoglin and vascular endothelial growth factor (VEGF) expression as prognostic markers in prostatic adenocarcinoma in 50 radical prostatectomy specimens. Cases were further categorized by Gleason score as follows: 8 to 10, 9 cases; 7(4 + 3), 9 cases; 7 (3 + 4), 14 cases; 6, 13 cases; and 4 or 5, 5 cases. All cases were immunostained for endoglin, CD31, and VEGF. Positively stained microvessels were counted in densely vascular foci in a x 400 field. VEGF staining intensity was scored on a 2-tiered scale. Results were correlated with survival and other parameters. Endoglin demonstrated significantly more microvessels than did CD31 (mean +/- SD, 37 +/- 15 vs 22 +/- 17; P < .001). VEGF expression was low in 21 cases (42%) and high in 29 (58%). Endoglin correlated positively with Gleason score, lymph node metastases, tumor stage, and preoperative prostate-specific antigen level (P < .05) but not with CD31. VEGF correlated significantly with angiolymphatic invasion and Gleason score (P < .05). A high endoglin microvessel count and VEGF expression correlated with shorter survival. Endoglin is a more specific and sensitive marker for tumor angiogenesis than CD31 and may serve as a prognostic marker for prostatic adenocarcinoma.     

VEGF-D in association with VEGFR-3 promotes nodal metastasis in human invasive lobular breast cancer

We assessed the expression of vascular endothelial growth factors (VEGF-C and VEGF-D) in breast cancer cells and the density of lymph vessels and VEGF receptor-3 (VEGFR-3)-positive vessels in and around the tumor in invasive lobular breast cancer. We found significant correlation between peritumoral lymph vessel density and presence of lymph node metastases (P=.001) and the number of metastatic lymph nodes (P<.001). A significant correlation was detected between tumor cell VEGF-D expression and lymph node status (P=.001) and density of lymphatic vessel endothelial receptor (LYVE)-1-positive vessels (P=.035). VEGFR-3+/VEGF-D+ and VEGFR-3+/VEGF-C+ tumors had a significantly higher number of metastatic lymph nodes than tumors with other staining patterns (P<.001). Tumors positive for neither VEGF-D nor VEGFR-3 had a lower density of LYVE-1+ vessels than tumors with other staining patterns (P=.033). Our results indicate that peritumoral lymph vessel density is associated with lymph node metastases in invasive lobular breast cancer and that invasive lobular cancer producing VEGF-D, surrounded by VEGFR-3+ vessels, has a significantly higher peritumoral lymph vessel density and a higher number of metastatic lymph nodes.     

Tumor angiogenesis correlates with metastasis in invasive prostate carcinoma.

Tumor growth and metastasis require angiogenesis; and microvessel density, a measure of tumor angiogenesis, correlates with metastasis in breast and lung carcinoma. To determine how microvessel density correlated with metastasis in prostate carcinoma, we counted microvessels within the initial invasive carcinomas of 74 patients (29 with metastasis, 45 without). Microvessels were highlighted by immunostaining endothelial cells for factor VIII-related antigen. Without knowledge of the patient's cancer stage, microvessels were counted in a 200 field (0.739 mm2) in the most active areas of neovascularization. The mean microvessel count in tumors from patients with metastases was 76.8 microvessels per 200 field (median, 66; standard deviation, 44.6). The counts within carcinomas from patients without metastasis were significantly lower, 39.2 (median, 36; standard deviation, 18.6) (P < 0.0001). Microvessel counts increased with increasing Gleason's score (P < 0.0001), but this increase was present predominantly in the poorly differentiated tumors. Although Gleason's score also correlated with metastasis (P = 0.01), multivariate analysis showed that Gleason's score added no additional information to that provided by microvessel count alone. Assay of microvessel density within invasive tumors may prove valuable in selecting patients for aggressive adjuvant therapies in early prostate carcinoma.     

Vascular endothelial growth factor expression in malignant melanoma: prognostic versus diagnostic usefulness.

Vascular endothelial growth factor (VEGF), an endothelial cell mitogen, plays a role in angiogenesis and progression in malignant melanoma. VEGF expression was examined in 62 biopsy specimens of melanocytic proliferations, including 45 malignant melanomas, 3 cellular blue nevi, 12 atypical compound nevi, and 2 Spitz nevi. The cases of malignant melanoma included 11 in situ melanomas, 18 Clark Level II, 9 Clark Level III, and 7 Clark Level IV tissue samples. All of the specimens were fixed in formalin and embedded in paraffin. Cytoplasmic immunoreactivity for VEGF was demonstrated in 19 (42%) of 45 melanoma samples, but there was no immunoreactivity for VEGF exhibited by any of the atypical compound melanocytic nevi, cellular blue nevi, or Spitz nevi (P < .009). Immunoreactivity for VEGF was found to be related to tumor thickness (as evidenced by Clark level [P < .03]) and to absence of regression (P < .04). Although VEGF is not a useful prognostic indicator for malignant melanoma, it may be useful as a discriminating factor between malignant melanoma and benign melanocytic lesions, and it may offer some insight into tumor growth.     

Tumor angiogenesis and metastasis--correlation in invasive breast carcinoma.

BACKGROUND. Experimental evidence suggests that the growth of a tumor beyond a certain size requires angiogenesis, which may also permit metastasis. To investigate how tumor angiogenesis correlates with metastases in breast carcinoma, we counted microvessels (capillaries and venules) and graded the density of microvessels within the initial invasive carcinomas of 49 patients (30 with metastases and 19 without). METHODS. Using light microscopy, we highlighted the vessels by staining their endothelial cells immunocytochemically for factor VIII. The microvessels were carefully counted (per 200x field), and their density was graded (1 to 4+), in the most active areas of neovascularization, without knowledge of the outcome in the patient, the presence or absence of metastases, or any other pertinent variable. RESULTS. Both microvessel counts and density grades correlated with metastatic disease. The mean (+/- SD) count and grade in the patients with metastases were 101 +/- 49.3 and 2.95 +/- 1.00 vessels, respectively. The corresponding values in the patients without metastases were significantly lower--45 +/- 21.1 and 1.38 +/- 0.82 (P = 0.003 and P less than or equal to 0.001, respectively). For each 10-microvessel increase in the count per 200x field, there was a 1.59-fold increase in the risk of metastasis (95 percent confidence interval, 1.19 to 2.12; P = 0.003). The microvessel count and density grade also correlated with distant metastases. For each 10-microvessel increase in the vessel count per 200x field, there was a 1.17-fold increase in the risk of distant metastasis (95 percent confidence interval, 1.02 to 1.34; P = 0.029). CONCLUSIONS. The number of microvessels per 200x field in the areas of most intensive neovascularization in an invasive breast carcinoma may be an independent predictor of metastatic disease either in axillary lymph nodes or at distant sites (or both). Assessment of tumor angiogenesis may therefore prove valuable in selecting patients with early breast carcinoma for aggressive therapy.     

Prognostic significance of intratumoral and peritumoral lymphatic density and blood vessel density in invasive breast carcinomas

We studied tumor lymphatic and vascular densities and lymphovascular invasion (LVI) as prognostic markers in 48 cases of invasive breast cancer treated with partial or total mastectomy and lymph node dissection. All cases were immunostained with D2-40 and CD31. Positively stained microvessels were counted in densely vascular/lymphatic foci (hot spots) at x400. The mean+/-SD peritumoral lymphatic microvessel density (LMD) was significantly higher than intratumoral LMD (9+/-7 vs 4+/-6; P< .01). There was a positive correlation of D2-40 LMD (peritumoral and intratumoral) and CD31 microvessel density counts with lymph node metastasis (r=0.35, 0.5, and 0.38), nuclear grade (r=0.36, 0.28, and 0.3), and stage (r=0.42, 0.56, and 0.49), respectively. Peritumoral and intratumoral D2-40 LMD correlated significantly with the presence of angiolymphatic invasion (detected by D2-40; r=0.54 and 0.54, respectively). D2-40 detected more LVI than H&E- and CD31-detectable vascular invasion (18/48, 5/48, 11/48, respectively). Increased D2-40 detected LVI, and high CD31 microvessel counts showed significant adverse effect on survival status.     

Overexpression of VEGF and angiopoietin 2: a key to high vascularity of hepatocellular carcinoma?

Hepatocellular carcinoma (HCC) is becoming one of the most common malignant tumors worldwide and is characterized by a high vascularity. Angiogenesis, formation of new microvessels, is critical for the growth and progression of various human solid tumors. Vascular endothelial growth factor (VEGF) and angiopoietins (Ang1 and Ang2) are endothelial cell-specific vasculogenic and angiogenic growth factors, but their expression and roles in HCC have not been extensively explored. The aim of this study was to determine the expression and cellular localization of VEGF, Ang1, and Ang2 in specimens of resected human HCC using in situ hybridization and immunohistochemical staining and to examine their relationship to microvessel density (MVD) and tumor size. We also investigated whether mutation of p53 protein might affect the expression of the above angiogenic growth factors. VEGF and Ang2 were strongly expressed and localized predominantly to cancer cells, whereas Ang1 was detected in supportive cells of large blood vessels, stromal cells, endothelial cells, and tumor cells. Expression of the VEGF protein and the Ang2 (but not Ang1) mRNA were strongly correlated with MVD (P <.05, P =.001) and tumor size (P <.05). There was also a strong correlation between VEGF protein and Ang2 mRNA expression (P <.001). However, no significant correlation was found between overexpression of p53 and the expression of VEGF, angiopoietins, or MVD. These findings suggest that overproduction of the angiogenic growth factors VEGF and Ang2 by HCC cells may increase vascularity and tumor growth in a paracrine manner. Our findings also suggest that interaction between VEGF and Ang2 may play a critical role in tumor angiogenesis in HCC.     

The angiogenic pathway "vascular endothelial growth factor/flk-1(KDR)-receptor" in rheumatoid arthritis and osteoarthritis

Active angiogenesis, together with an up-regulation of angiogenic factors, is evident in the synovium of both rheumatoid arthritis (RA) and osteoarthritis (OA). The present study assessed, by immunohistochemistry, the microvessel density in the synovium of these arthritides and in normal controls, in relation to the expression of the angiogenic factors vascular endothelial growth factor (VEGF) and platelet-derived endothelial cell growth factor (PD-ECGF) and the apoptosis-related proteins bcl-2 and p53. More importantly, using the novel 11B5 MAb, the activated "VEGF/flk-1(KDR)-receptor" microvessel density was assessed. VEGF expression in fibroblasts was diffuse in both RA and OA. Diffuse PD-ECGF expression of fibroblasts was noted in all cases of RA, while fibroblast reactivity was focal in the OA material. The standard microvessel density (sMVD), as assessed with the anti-CD31 monoclonal antibody (MAb), was higher in RA (64+/-12) and in OA (65+/-16) than in normal tissues (52+/-8; p=0.008 and 0.0004, respectively). The activated microvessel density (aMVD), assessed with the 11B5 MAb, was significantly higher in RA (29+/-10) than in OA (17+/-4; p<0.0001) and than in normal tissues (14+/-2; p<0.0001). The "activation ratio" (aMVD/sMVD) was statistically higher in RA (0.46+/-0.17) than in OA and normal synovial tissues, the latter two having a similar ratio (0.28+/-0.08 and 0.26+/-0.03, respectively). Cytoplasmic bcl-2 expression was frequent in the synovial cells of OA, but rare in RA. Nuclear p53 protein accumulation was never observed. It is suggested that the angiogenic pathway VEGF/flk-1(KDR) may play an important role in the pathogenesis of RA and OA. Thus, failure of VEGF/flk-1(KDR) activation, in the presence of increased VEGF expression, may indicate a synovium with an impaired capacity to establish a viable vasculature, consistent with the degenerative nature of OA. On the other hand, the activated angiogenesis in RA shows a functional, still pathologically up-regulated VEGF/flk-1(KDR) pathway. Whether restoration of an impaired VEGF/flk-1(KDR) pathway in OA, or inhibition of this in RA, would prove of therapeutic importance requires further investigation.     

VEGF expression correlates with microvessel density in Philadelphia chromosome-negative chronic myeloproliferative disorders

We examined microvessel density (MVD) and immunohistochemical expression of vascular endothelial growth factor (VEGF) in the bone marrow biopsy specimens of 98 patients with Philadelphia chromosome-negative (Ph-) chronic myeloproliferative disorders (CMPDs). There were significantly more MVD "hot spots" in chronic idiopathic myelofibrosis (CIMF; mean +/- SD, 25.6 +/- 6.3) and polycythemia vera (PV; 20.7 +/- 10.2) cases than in essential thrombocythemia (ET) cases (10.1 +/- 4.5) and normal control (NC) samples (7.5 +/- 3.6) (P < .05). Similar results were found using a semiquantitative method (P < .0001). A calculated VEGF index (VEGF(i)) was higher in CIMF (0.29 +/- 0.15) and PV (0.28 +/- 0.20) cases than in ET (0.12 +/- 0.05) and NC (0.08 +/- 0.04) cases (P < .0001). MVD and VEGF(i) were higher in the myelofibrotic phases of CIMF and PV. There was a direct correlation between VEGF(i) and MVD when considering the Ph- CMPDs together (r = 0.67; P < .001) and when considering PV (r = 0.79; P < .001) and CIMF (r = 0.40; P = .013) as individual entities. Our data could provide a rationale for directly targeting VEGF or endothelial cells in CIMF and PV.     

Evaluation of angiogenesis and vascular endothelial growth factor expression in the bone marrow of patients with aplastic anemia

It is generally appreciated that bone marrow function and growth of myelopoietic cells depends on an intact microvasculature. A pivotal regulator of angiogenesis is vascular endothelial growth factor (VEGF). Here, we describe analysis of VEGF expression and microvessel density in the bone marrow of patients with aplastic anemia by immunohistochemistry. Bone marrow was examined at diagnosis and at the time of hematological remission after immunosuppressive therapy using anti-thymocyte globulin, cyclosporin A, and glucocorticoids or allogeneic stem cell transplantation. At diagnosis, both VEGF expression and microvessel density were found to be significantly lower in aplastic anemia compared to normal bone marrow (aplastic anemia, 1.1 +/- 0.7 events per field, versus controls, 5.9 +/- 3.0 events per field; P < 0.05). In response to successful therapy, VEGF and microvessel density in the bone marrow increased substantially. Serum VEGF levels were also found to be significantly lower at diagnosis in aplastic anemia compared to healthy controls (aplastic anemia, 51 +/- 35 pg/ml versus controls, 444 +/- 220 pg/ml; P < 0.05). VEGF in the serum increased substantially after successful immunosuppressive therapy or stem cell transplantation (P < 0.05). Taken together, these data show that aplastic anemia is associated with reduced angiogenesis and reduced VEGF expression.     

Microvessel quantitation and prognosis in invasive breast carcinoma.

The prognostic significance of microvessel quantitation in invasive breast carcinoma was analyzed in a study group that comprised 88 patients with axillary node-negative carcinoma and 32 patients with axillary node-positive carcinoma who had a minimum follow-up period of 9 years. Microvessels were identified by immunohistochemistry using antibodies to endothelial markers, including factor VIII-related antigen and blood group isoantigens (ABH). Factor VIII-related antigen staining provided more consistent results for microvessel quantitation than did staining for ABH isoantigens. The three most vascular areas within a tumor were selected, and the microvessels within a x200 microscopic field of each area were counted by two investigators simultaneously. Node-positive carcinomas demonstrated significantly higher microvessel counts than did node-negative carcinomas (mean +/- SD, 99 +/- 42 and 73 +/- 22, respectively; P less than .001). In node-negative carcinomas, tumors from patients who experienced distant recurrence had higher microvessel counts than did tumors from patients who were disease-free (84 +/- 19 and 70 +/- 22; P = .01). Similarly, in patients with node-positive carcinoma, microvessel counts were considerably higher in tumors from patients who experienced distant recurrence than in patients who did not, although the difference did not reach statistical significance (113 +/- 44 and 93 +/- 34, respectively). Among patients with node-negative carcinoma, those with a microvessel count of less than 84 had a recurrence rate of 20% compared with 57% in patients with counts greater than 84 (P = .003). Microvessel counts were independent of histologic parameters, ploidy status, and S-phase fraction but correlated with peritumoral vascular invasion. Both microvessel counts and vascular invasion were independent prognostic parameters by multivariate analysis. High vessel counts may represent increased tumor angiogenesis and are correlated with tumor aggressiveness. Microvessel quantitation may be an additional prognostic factor that, when used in conjunction with more established parameters, can help in appropriate patient management.     

Angiogenic and lymphangiogenic microvessel density in breast carcinoma: correlation with clinicopathologic parameters and VEGF-family gene expression.

Angiogenesis and lymphangiogenesis are essential for breast cancer progression and are regulated by vascular endothelial growth factors (VEGF). To determine clinical and molecular correlates of these processes, we measured blood and lymphatic vascular microvessel density in 29 invasive carcinomas (22 ductal, six lobular, one papillary), using the vascular marker CD31 and the novel lymphatic marker D2-40. Microvessel density was assessed microscopically and by image cytometry, and was compared with tumor histology, grade, stage, lymph node metastasis, hormone receptors, HER2/neu status, and expression of VEGF, VEGF-C and VEGF-D by immunohistochemistry or quantitative RT-PCR. Strong correlation was observed between visual and image cytometric microvessel density using D2-40 but not CD31 (P=0.016 and 0.1521, respectively). Image cytometric CD31 microvessel density correlated with tumor size, grade, stage and lymph node metastasis (P=0.0001, 0.0107, 0.0035 and 0.0395, respectively). D2-40 microvessel density correlated with tumor stage (P=0.0123 by image cytometry) and lymph node metastasis (P=0.0558 by microscopy). Immunohistochemical VEGF signal in peritumoral blood vessels correlated with image cytometric CD31 and D2-40 microvessel density (P=0.022 and 0.0012, respectively), consistent with the role of VEGF in blood and lymphatic vascular growth. Intratumoral VEGF-C and VEGF-D expression by quantitative RT-PCR correlated with D2-40 (P=0.0291 by image cytometry) but not with CD31 microvessel density, which could suggest a selective role of VEGF-C and VEGF-D in lymphangiogenesis. CD31 and D2-40 microvessel density correlated significantly with several prognostic factors, including lymph node metastasis. Thus, measurements of angiogenesis and lymphangiogenesis may have utility for breast cancer pathology, particularly for estimation of metastatic risk.     

Synergistic effect of sustained delivery of basic fibroblast growth factor and bone marrow mononuclear cell transplantation on angiogenesis in mouse ischemic limbs

Combined angiogenic therapies may be superior to single angiogenic therapy for treatment of limb ischemia. First, we investigated whether the angiogenic efficacy of basic fibroblast growth factor (bFGF) administration and bone marrow-derived mononuclear cell (BMMNC) transplantation can be enhanced by sustained delivery (SD) of bFGF and BMMNC transplantation using a matrix, respectively, in mouse ischemic limbs. Next, we investigated whether the angiogenic efficacy of combination of two angiogenic strategies is superior to either strategy alone. One day after surgical induction of mouse hindlimb ischemia, mice were randomized to receive either no treatment, daily injection (DI) of bFGF, SD of bFGF, BMMNC transplantation using culture medium, BMMNC transplantation using fibrin matrix (FM), or combination of SD of bFGF with BMMNC transplantation using FM. The SD of bFGF significantly increased the microvessel density, compared with DI of bFGF (659+/-48/mm2 versus 522+/-39/mm2, p<0.05). BMMNC transplantation using FM significantly increased the microvessel density, compared with BMMNC transplantation using culture medium (523+/-103/mm2 versus 415+/-75/mm2, p<0.05). Importantly, combination of bFGF sustained release with BMMNC transplantation using FM further increased the densities of microvessels and arterioles, compared to either strategy alone (p<0.05). The SD method of angiogenic protein and cell transplantation using matrix potentiate the angiogenic efficacy of bFGF and BMMNC transplantation, respectively, for limb ischemia. In addition, the combined therapy of SD of bFGF and BMMNC transplantation synergistically enhances angiogenesis in mouse ischemic limb, compared to each separate therapy.     

Association of mast cells with microvessel density in urothelial carcinomas of the urinary bladder

This study aims to investigate the relation of mast cell (MC) accumulation with tumor grade and stage in urothelial carcinomas of the urinary bladder and to determine its relationship with angiogenesis. A total of 78 urothelial carcinomas obtained by transurethral resection were investigated immunohistochemically by using c-Kit (CD117) and anti-CD34. The correlation between MC counts and microvessels was evaluated and compared with histopathologic parameters including tumor stage and grade. There were significant correlations between MC counts, grade, and stage (P < .05; r = 0.69 and 0.63, respectively). However, MC counts in adjacent nontumoral bladder mucosa significantly were higher than the MC counts in tumoral zone (P < .001). On the other hand, significant correlation was found between the number of MCs in tumoral zone and the microvessel density (P < .05, r = 0.56). The results of our study suggest that c-Kit positive MCs in tumoral zone may contribute to tumor angiogenesis and play a significant role in tumor growth and invasion. Further studies are needed to support these observations.     

The relationship between microvessel count and the expression of vascular endothelial growth factor, p53, and K-ras in non-small cell lung cancer

Using immunohistochemical staining, we studied the relationship between the microvessel count (MC) and the expression of K-ras, mutant p53 protein, and vascular endothelial growth factor (VEGF) in 61 surgically resected non-small cell lung cancers (NSCLC) (42 squamous cell carcinoma, 14 adenocarcinoma, 2 large cell carcinoma, 2 adenosquamous carcinoma, and 1 mucoepidermoid carcinoma). MC of the tumors with lymph node (LN) metastasis was significantly higher than that of tumors without LN metastasis (66.1+/-23.1 vs. 33.8+/-13.1, p<0.05). VEGF was positive in 54 patients (88.5%). MC was 58.1+/-25.2 (mean+/-S.D.) in a x200 field, and it was significantly higher in VEGF(+) tumors than in VEGF(-) tumors (61.4+/-23.7 vs. 32.9+/-23.8, p<0.05). VEGF expression was higher in K-ras-positive or mutant p53-positive tumors than in negative tumors (p<0.05). MC was significantly higher in K-ras(+) tumors than in K-ras(-) tumors, although it did not differ according to the level of mutant p53 protein expression. Survival did not differ with VEGF, mutant p53, or K-ras expression, or the level of MC. In conclusion, there is a flow of molecular alterations from K-ras and p53, to VEGF expression, leading to angiogenesis and ultimately lymph node metastasis. Correlations between variables in close approximation and the lack of prognostic significance of individual molecular alterations suggest that tumorigenesis and metastasis are multifactorial processes.     

Vascular endothelial growth factor expression and neovascularization in non--small cell lung carcinoma

The prognostic significance of microvascular density (MVD) and vascular endothelial growth factor (VEGF) expression were investigated in 15 patients with adenocarcinoma (AC) and 15 patients with squamous cell carcinoma (SCC). Immunohistochemically, VEGF and factor VIII were applied. The average microvessel counts were given as MVD, and VEGF expression was given as VEGF percentage area and VEGF staining degree. Higher values of MVD were obtained in patients with AC (11.47 +/- 3.48) when compared with patients with SCC (7.47 +/- 2.50; P = .001) and also in patients at early stages of disease (10.77 +/- 3.24) when compared with patients at advanced stages (8.47 +/- 3.64; P = .050). A significant correlation was shown between MVD and VEGF percentage area (P = .006) and between VEGF percentage area and VEGF staining degree (P = .000). No significant difference was found in VEGF percentage area between patients with SCC and AC and between patients at early and advanced stages. In conclusion, VEGF or MVD should not be regarded as a solitary prognostic factor but should be supported by other prognostic factors.     

CD34 microvessel density and VEGF expression in basal and squamous cell carcinoma

Angiogenesis is a central process in the growth of solid tumors. The purpose of our study was to analyze the angiogenic pattern in squamous and basal cell carcinomas and to point out differences in microvessel density that could explain their different biological behaviour. Thirty-nine skin tumors (26 basal and 13 squamous cell carcinomas) were analyzed. In all samples, the microvessels density (MVD) and the levels of vascular endothelial growth factor mRNA (VEGFmRNA) were analyzed, together with the inter-relationship between these two variables. Using the median value of the entire series (33 vessels per 2.22 mm2), tumors with low and high MVD were identified. The majority of cancers with high vascularization belonged to the squamous histotype (12 of 39), while 19 of the 26 basal cell carcinomas showed a lower number of microvessels than the median value (p = 0.0001). The median value of VEGFcDNA quantitation allowed us to distinguish tumors with high VEGF expression (> 470 molecules cDNA) from those with low (< or = 470 molecules) VEGF expression: 20 of the 26 basal cell carcinomas showed low VEGF expression, while 11 of the 13 squamous cell carcinomas showed high VEGFcDNA levels (p = 0.0003). Moreover, a significant association between a high microvessel density and high VEGFmRNA levels (p = 0.006) was found. Furthermore, when studying VEGF expression by immunohistochemistry, we obtained similar results and noted a correlation with VEGFmRNA expression (p < 0.0001). The association between high vascularization, high VEGF levels, and squamous cell histotype suggests the possible role of neoangiogenesis in determining the more aggressive biological behaviour of this type of cancer.     

Expression of vascular endothelial growth factor in diffuse malignant pleural mesothelioma

Angiogenesis is an important part of normal and pathological processes, including tumour growth, metastasis, inflammation and wound healing. VEGF is the best known angiogenic factor, implicated in tumour-associated microvascular hyperpermeability and carcinogenesis. We investigated 103 malignant pleural mesotheliomas, analysing the expression of vascular endothelial growth factor using immunohistochemistry and insitu hybridization. The grade of microvessel density was assessed with the aid of anti-factor-VIII antibodies. An increased expression of VEGF was found in biphasic and epithelioid mesotheliomas, correlating in a statistically significant manner (P<0.042). Insitu hybridization confirmed the specificity of VEGF mRNA expression. There was a robust correlation between VEGF expression and increased microvessel density (P<0.001), and positive mesotheliomas had significantly higher microvessel densities than negative specimens. There was also a significant correlation between microvessel density and histological pattern. As growth pattern tended towards biphasic and sarcomatoid mesotheliomas the density of micovessels decreased (P<0.05).