Isochromosome 5p, a novel recurrent abnormality in breast cancer: is it a common abnormality in cancer?
BACKGROUND
The detection of recurring genetic changes in breast cancer can be extremely difficult. The tumors display very complex structural chromosomal rearrangements the origin of which are often very difficult to establish. The identification of recurrent chromosomal changes is a useful strategy for understanding tumorigenesis and specific chromosomal associations. Isochromosome i(5p) is a frequent finding in several types of cancer but it has been rarely described in breast cancer. The aim of the present study was to investigate the presence of i(5p) in primary breast tumors.


METHODS
Sixteen cases of breast cancer were cytogenetically studied by direct culture of cancerous cells and G-banding technique. We focused on structural aberrations of chromosome 5 in order to identify the presence of i(5p) in breast cancer.


RESULTS
All the cases presented complex chromosomal changes with hyperploidization and various unidentified marker chromosomes being the prominent finding. Among 16 cases studied 6 cases presented an i(5p). No other structural abnormalities of chromosome 5 could be identified.


CONCLUSIONS
The presence of i(5p) in breast tumors suggests that this chromosomal abnormality plays an important role in the development of breast cancer. Isochromosome 5p needs to be further molecularly analyzed as a candidate region for the isolation of genes related to carcinogenesis. Moreover, the fact that i(5p) has been described in several different tumor types suggests that there are no fundamental tissue-specific differences in the genetic mechanisms leading to tumorigenesis.
Panani
Anna D
AD
Critical Care Department, Medical School of Athens University, Evangelismos Hospital, Ipsilandou 45-47, Athens 10676, Greece. apanani@med.uoa.gr
D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D002869:Chromosome Aberrations; D002871:Chromosome Banding; D002895:Chromosomes, Human, Pair 5; D005260:Female; D006801:Humans; D018404:Isochromosomes; D014407:Tumor Cells, Cultured