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6th ESACP Congress, Heidelberg, April 7-11, 1999 |
A136
Angiogenesis is tightly regulated in normal physiological conditions; in
cancer its control mechanisms are disturbed, leading to growth of newly
formed blood vessels. Folkman J. (1) has first suggested that neoangiogenesis
is essential to tumour progression. There is now evidence that tumour mass
expansion and dissemination require neovascularisation. Tumour angiogenesis
is more often heterogeneous and tightly packed microvessels are localised
in so-called ôhot spotsö. Quantification of angiogenesis in these areas has
proved to be of clinical interest. Microvascular density strongly correlates
with grade, prognosis of numerous cancers and occurrence of metastases.
Multivariate analysis of prognosis factors has underlined the particular
interest of angiogenesis quantification in breast and ovarian carcinomas
(2, 3). These results lead to a new concept in anticancer therapy strategy,
targeting both tumour and endothelial cells. Specific antiangiogenic
treatments against solid tumours were introduced six years ago and, in 1996,
nine molecules were tested in clinical trials. Prognosis and therapeutic
assessments require neoangiogenesis quantification. For this purpose,
methods which are less tedious, less time consuming and more reproducible
than counting through the microscope lens must be developed and tested.
The different approaches found in literature and unsolved problems will be
discussed here. Reproducible selection of hot spots seems to be the first
and most difficult problem to overcome. Manual, stereologic and even semi
-automated techniques have been proposed, nevertheless, none of them fully
solves this problem. Thus, identification of areas of intensive
neovascularisation as well as angiogenesis quantification must be carried
out by a fully automated counting method.
QUANTIFICATION OF TUMOUR ANGIOGENESIS : PART I - CLINICAL RELEVANCE AND
PROBLEMS CAUSED BY MICROVESSEL DETECTION AND QUANTIFICATION
Tran TKN
Centre Francois Baclesse, Caen, Pôle Traitement et
Analyse d'Images de Basse Normandie, Caen, France
1. Folkman J (1971), N. Engl. J. Med., 285:1182-1186
2. Toi M, Kashitani J, Tominaga T (1993), Int. J. Cancer, 55:371-374
3. Schoell W, Pieber D, Reich O, Lahousen M, Janicek M, Guecer F,
Winter R (1997), Cancer, 80:2257-62