Berlin, Germany: Some women who carry the BRCA gene mutation, which predisposes to breast cancer, may choose to have a prophylactic mastectomy rather than undertake lifetime surveillance, a Dutch scientist will tell the 6th European Breast Cancer Conference (EBCC-6) today (Wednesday 16 April). The mastectomy option appears to give an excellent result in avoiding breast cancer, with a remaining risk of less than 1%, Dr. Reinie Kaas, from the Surgical Department of the Netherlands Cancer Institute, Amsterdam, The Netherlands, will say.
Dr. Kaas set out to study the effects of prophylactic mastectomy in 250 patients who were BRCA carriers. It was thought that after such a mastectomy the risk of being diagnosed with breast cancer was about 5%, she says and therefore there was debate about whether continued surveillance was necessary or not. We decided to try to answer this question in order that women at high risk should be able to make an informed choice.
Women with mutations in the BRCA1 or BRCA2 genes have an estimated lifetime risk of developing breast cancer of about 85%. Currently strategies to deal with this risk are surveillance with monthly breast self-examination, bi-annual clinical breast examination by a physician and annual mammography plus breast MRI, or prophylactic mastectomy, where the entire breast is removed. About half of the carriers choose the latter strategy. The surveillance strategy does not prevent breast cancer, and especially in BRCA1 carriers, who mostly have fast growing tumours, 25-30% of carriers are diagnosed when the tumour is already more than 2cm in diameter.
Dr. Kaas and her team found that only one out of the 250 carriers studied was diagnosed with a breast cancer, and this was likely to be because the axillary tail (a small part of the breast that extends towards the armpit) had not been completely removed. Our epidemiologists are investigating how many breast cancers are avoided up to the age of 80 in these women, she says. But on current evidence we can safely state that continued follow-up, which can be costly as well as stressful for the patient, is not warranted in patients who have had a prophylactic mastectomy. Surveillance in those BRCA carriers who do not opt for mastectomy has to start at an early age, and the frequent visits to the doctor and the many examinations which need to be undertaken regularly can be a source of great stress for many women.
However, the decision to remove healthy breasts is solely the decision of the woman, and healthcare services should not press women to make this choice simply to reduce costs.
In another presentation to the conference tomorrow (Wednesday) Dr. Yvonne Kamm, a medical oncologist from the Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands, will say that the costs of screening for BRCA carriers are very high, and even more so because the MRI that is used can have a high false positive rate, leading to further investigations.
The MRI is expensive in itself, but useful because it can detect very small tumours which might not be picked up otherwise. But it also detects many other abnormalities that are not cancer, and this implies not just extra cost but also considerably anxiety for the women concerned, she says.
Between September 1999 and 2005, Dr. Kamm and her team screened 196 women at risk of hereditary breast cancer. When an abnormality was found, the women underwent further investigations. The women were screened for a median period of 2 years; this included 1149 breast examinations, 494 mammograms, and 436 MRI scans. Abnormalities led to further investigations; 32 breast examinations, 17 mammograms, 64 MRI scans, 114 ultrasound examinations, and 48 biopsies.
The cost of the first screening programme was 254 per woman year, and the extra costs of further investigations 61 per woman year. During the 6 year period 13 cancers were found.
The total costs to find one breast cancer were high 13168, says Dr. Kamm. We know that such intensive screening works, and that it can find breast cancer at an early stage. Therefore, we have made the choice to screen intensively women at very high risk from breast cancer.
|Contact: Mary Rice|
ECCO-the European CanCer Organisation