Background

Current research on molecular cytogenetics of solid tumours is directed towards the identification of recurrent chromosomal rearrangements which breakpoints may pinpoint genome regions harbouring genes involved in the initiation and progression of different tumour types.

Although chromosomal changes associated with pathogenetic pathways are largely tumour-specific, an integrated view of the cytogenetic patterns of distinct tumours is necessary to tumour classification, environmental mutagenesis and to perceive the multifaceted role of several cancer genes lying at chromosomal breakpoints. Exchanges in the expertise that separate groups have achieved on different tumours may greatly accelerate basic research on as yet unidentified chromosomal changes in human tumours and provide guidelines for translation of genome discoveries to clinical and diagnostic applications.

Several multi-target Fluorescent In Situ Hybridization (FISH) techniques are applied to tumour nuclei and metaphases to simultaneously detect increased/decreased dosage of different chromosomes/chromosomal regions and multiple chromosome aberrations including complex markers. Comparative Genome Hybridization (CGH) techniques on slides, chips or filters accurately detect copy number abnormalities in a single analysis providing a powerful research approach for identifying new genetic abnormalities. Tissue microarray technology ("tissue chips") for molecular profiling of tumour progression makes FISH a high-throughput tool for cancer genetics.

A resource of mapped BACs for use in FISH analysis of chromosome rearrangements in human tumours has been recently generated.

An increasingly high number of breakpoint-spanning probe contigs is also being developed by investigators working on defined genome regions. Sharing of this repertoire combined to rapid communication on novel technologies may allow molecular cytogeneticists to achieve goals precluded a few years ago.

Molecular cytogenetics of solid tumours is a fast-growing field. For the most commonly investigated tumours knowledge on primary chromosome aberrations needs to be transferred to diagnostic services, while for a few other tumours identification of key chromosomal changes awaits further investigation.

Therefore we are convinced that it is particularly timely and necessary to establish a European network in order to promote contacts and exchanges of experience and approaches among laboratories involved in basic research and diagnostic services on solid tumours. This network should include groups devoted to development of new resources and technological tools, which may provide new insights into basic pathogenetic mechanisms or may improve routine investigation.

Investigators experienced on specific tumour types should compare their expertises and set up guidelines for optimization of diagnostic services. Interaction between these specialized labs and investigators or companies working on new tools and reagents is recommended to guarantee the application of the most rapid and economic procedures.

Currently the European Cytogeneticist Association (ECA) has enhanced cooperation of investigators in the field of basic and applied cytogenetics. Nevertheless contacts are restricted to a few international scientific events which are held every other year. Although these scientific programmes allow researchers to meet, they are inadequate to build up a continuous cooperation in a specific field, such as that of cytogenetics of benign and malignant solid tumours. The present COST Action aims at establishing a permanent network among outstanding groups located in different European laboratories which contribute actively to advances in the field of molecular cytogenetics of solid tumours on sides as different as that of new high resolution technologies (Multiplex FISH, CGH on arrays etc), set up of FISH probes spread over the whole genome, disclosure of novel cytogenetic markers (in neuroblastoma, breast cancer, soft tissue sarcomas, benign solid tumours) and the comprehensive catologuing of cancer breakpoints. The situation in European countries could be estimated by the contributions of the researchers coming from the Member States to relevant scientific meetings such as the First European Cytogenetics Conference (Athens, Greece, 1997), the Second European Cytogenetics Conference (Wien, Austria, 1999) in which solid tumours have been the topic of several plenary lectures and workshops fully dedicated to this topic such as the 6th European Workshop on Cytogenetics and Molecular Genetics of human solid tumours (Saarbrucken, Germany, 1998).