Genetic test for cancer has mostly been very beneficial to patients.Around six to eleven per cent of breast, prostate and colorectal cancers have a clear genetic cause. And we now know at least some of the genes involved, and can test for them. Dr.Lindsay Prior, a sociologist at Cardiff University felt that at least, few of those referred for genetic counselling will be advised to have the test. The reasons are technical, ethical and psychological.
It is vital that the patient's family history be considered alongside the laboratory evidence for the presence of a cancer gene. This needs to be checked from an independent source, such as a cancer registry. If someone doesn't have a family history, then it is pointless to test for a mutation and to interpret the result.
These issues are important, given that genetic testing can - in theory - be done 'over the counter'. That is, you could buy a kit and test for a cancer gene. But without your family history and counselling you would not be able to interpret your individual risk of cancer. That's why the UK Human Genetics Commission is now studying the problem of the test kits, and has concluded that laboratory evidence alone could be highly misleading.