Women who opt for preventive surgery because of a family history of breast or ovarian cancer reduce their risk, but it is not clear by how much.

Carrying mutations in the BRCA1 or BRCA2 genes is known to increase a woman's risk of breast or ovarian cancer. These women may well have seen close female relatives already affected by the disease. One way of avoiding this enhanced risk is to opt for prophylactic removal of the breasts or ovaries.

Studies have shown that this reduces the risk of cancer greatly, compared to not having surgery. But researchers at the Netherlands Cancer Institute in Amsterdam now question the accuracy of such studies. They say these could be influenced by various biases. For instance, when comparing surgery versus non-surgery women, it's important to be aware that they come from different families and may have a different degree of genetic risk.

It's vital that these potential biases are considered in more detail in the light of future research. After all, women make serious decisions about their future health in the light of the results of such research. It may be that non-invasive monitoring of the breasts - by magnetic resonance imaging - or chemoprevention by new drugs would be a better option for at least some women.

Source

Journal of the National Cancer Institute 2nd July 2003