Tumour suppressor genes and risk of metastasis in ovarian cancer.

Abstract

The silent onset of ovarian cancer often leads to metastatic spread before diagnosis can be made. The cause remains unknown, but molecular studies are beginning to reveal some mechanisms. Inactivation of tumour suppressor genes is thought to be responsible for initiating many forms of cancer. Studies of allele loss indicate areas of genome where inactivation may occur. We recently examined the relation between the clinical stage of epithelial ovarian cancer and allele loss at three loci on chromosome 17: progressive loss was detected with advancing stages of disease.' The clinical stage of a tumour defines the extent of the disease and is the best determinant of prognosis for most forms of cancer. It depends on the time elapsed before diagnosis, hence the value placed on early detection. The histopathological grade, however, better describes the intrinsic nature of the tumour: well differentiated tumours are slow growing whereas undifferentiated, anaplastic tumours metastasise rapidly. Thus poorly differentiated tumours tend to be diagnosed at a more advanced stage. At the molecular level one might anticipate less damage to genetic material with well differentiated tumours.