Microvessel count is predictive of patients' survival in laryngeal squamous-cell carcinoma

Quantitative evaluation of angiogenesis in laryngeal cancer by digital image measurement of the vessel density

OBJECTIVE

the aim of our study was determination of the relationship between angiogenesis and clinical as well as histological features in laryngeal cancer.

METHODS

we used two different methods of estimation of the amount of microvessels in the series of 55 cases, e.g. classical count of endothelial cells group (h-MVD) and digital image measurement of the vessel density (VD).

RESULTS

neither h-MVD nor VD correlated significantly with clinical features of the tumour. The results of VD examination correlated significantly with the existence of nodal metastases (P=0.02). The relationship between h-MVD and N status was on the statistical borderline (P=0.07). Multivariate analysis of Cox's proportional hazards model revealed that only N status correlated significantly with patients' survival.

CONCLUSION

our results indicate that measurements of angiogenesis in laryngeal cancer may be of some value in predicting N status in laryngeal cancer patients. This issue should be confirmed in prospective studies.

Microvessel density and endothelial basement membrane composition in laryngeal squamous cell carcinomas

In this retrospective study we morphometrically evaluated the density of small blood vessels (microvessel density; MVD) in laryngeal squamous cell carcinomas (SCC) in order to find out if the vascular density provides relevant information on the biology and prognosis of this tumor type. In addition, we investigated the composition of the endothelial basement membrane (BM) to analyze qualitatively the role of the major BM components during tumor-associated angiogenesis. For the immunohistochemical staining of the blood vessels we used the endothelial cell marker CD31 and the BM was analyzed by immunostaining for the major components collagen-IV, laminin-1 and perlecan. Beneath the normal mucosa a mean of 18 vessels/0.41 mm2 was found. Invasive carcinomas showed a significant increase in blood vessel density to 36.3 vessels/0.41 mm2 regardless of the degree of tumor cell differentiation. Interestingly, the highest vascular density was found beneath dysplastic, but non-invasive epithelia (45.5 vessels/0.41 mm2), particularly when associated with a strong lymphoplasmacytic cell infiltration. Statistical analysis revealed a highly significant correlation between MVD and the lymphoplasmacytic infiltrate. However, we did not find any significant correlation between MVD and other clinical/biological parameters. Qualitative analysis of the endothelial BM revealed an "earliest" occurrence of laminin-1 in the obviously newly formed vessels, while collagen IV and perlecan occur at more pronounced stages of vessel formation. There was, however, no prognostically relevant information available from endothelial BM analysis. In summary, at present we do not consider the MVD in SCC of the larynx to be a prognostic factor for the individual outcome of the patient.

Angiogenic factors in laryngeal carcinomas: do they have prognostic relevance?

Angiogenesis is a cascade-like mechanism essential for tumour growth and metastasis. Recently developed inhibitors of angiogenesis have already proven their benefit in anticancer treatment. Therefore the existence of angiogenic molecules in individual tumours is of major interest. The factors most frequently contributing to angiogenesis are basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF) and some matrix metalloproteinases (MMPs). In order to evaluate the prognostic significance of these molecules we investigated the distribution pattern of VEGF, bFGF, MMP-2 and MMP-9 in 41 laryngeal carcinomas using immunohistochemical methods. The results were correlated with clinicopathological parameters, i.e. T and N stage, histological grading, freedom from disease, overall survival and microvessel density (MVD). Only VEGF revealed a correlation with MVD (p = 0.01) and a weak association with histological grading (p = 0.06). Even though there is controversy about published data on the prognostic relevance of angiogenic factors, our results suggest that the factors examined in this study are not suitable for prognosis in larynx cancer patients.