Screening in breast cancer families: is it useful?

In 5% of the cases of breast cancer, the condition is attributable to a genetic predisposition. The clinical relevance of inherited forms of cancer lies in the fact that periodic screening of close relatives of patients may prevent disease and death due to cancer. Although surveillance programmes for hereditary cancers have been recommended for many years, there is still little or no evidence that surveillance will improve the prognosis. In particular, screening for breast and ovarian cancers gives rise to many problems, because there is no precursor lesion that can easily be identified, such as an adenomatous polyp in familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer. This means that prospective controlled studies are urgently needed to assess the value of the recommended screening protocols. National and regional hereditary cancer registries may play an important role in the evaluation of the effect of long-term surveillance. Presymptomatic testing based on DNA technology will probably become feasible for breast cancer in the near future. A major advantage of DNA analysis in this context is that screening can be focused on high-risk individuals and the family members at low risk can be less rigorously followed. Because of unanticipated consequences associated with DNA analysis, much research remains to be done to define the psychosocial implications of presymptomatic DNA diagnosis.