A new US study shows that more American women are choosing to have both breasts removed when only one breast is affected by breast cancer. In the first
study to look at the trend across the US, researchers found that the number of women electing to have contralateral prophylactic mastectomy (CPM) to prevent
cancer in the opposite healthy breast has gone up by 150 per cent between 1998 and 2003.
The study is published in the 22 October early online issue of the Journal of Clinical Oncology and is the work of Dr Todd M. Tuttle, chief of surgical oncology and associate professor of surgery at the University of Minnesota, Minneapolis and colleagues.
The authors raised concern that a strategy as aggressive as CPM may be unnecessarily drastic, since most patients are unlikely to develop cancer in the second breast. The risk of it spreading to other parts of the body tend to be higher than the risk of it spreading to the second breast, they said.
As Tuttle explained:
"Although breast cancer is now often diagnosed at earlier stages, we're seeing more women having contralateral prophylactic mastectomy, even though there are very little data showing that this irreversible procedure improves overall survival."
Tuttle said it was important to find out why this was happening, in order to better inform women about their options, including the pros and cons of less invasive procedures.
Tuttle and colleagues searched in the Surveillance, Epidemiology, and End Results (SEER) database to find out what treatments patients diagnosed with unilateral breast cancer between 1998 to 2003 underwent. SEER provides detailed information on cancer diagnoses and treatments for 16 regions of the US.
The researchers calculated the rate of CPM as a proportion of all patients who had any kind of surgery and also as a proportion of mastectomies (i.e. both single and double) but not other kinds of surgery.
The results showed that:
- There were 152,755 patients with stage I, II and III breast cancer.
- Of these, 59,460 patients underwent unilateral (one-sided) mastectomy and 4,969 others who were candidates for single mastectomy underwent CPM.
- The proportion of CPM patients was 3.3 per cent of all patients who had any kind of surgery and 7.7 per cent of those who had mastectomies.
- The rate of CPM increased significantly from 1.8 per cent of all surgeries in 1998 to 4.5 per cent in 2003.
- As a proportion of all mastectomies, the rate of CPM also went up significantly from 4.2 per cent in 1998 to 11.0 per cent in 2003.
- The increased rates were the same for all cancer stages and continued to the end of the period of study.
- Younger, non-Hispanic whites, and women with lobular breast cancers and a previous cancer diagnosis were more likely to have CPM.
He also said that improvements in surgery, such as less invasive mastectomy and better reconstruction techniques, may be persuading women to have both breasts removed at the same time rather than just the affected one.
However, Tuttle was concerned that women were perhaps making the decision to opt for CPM too quickly, at a time when they were vulnerable. He suggested it might be better for patients to have the urgent treatment that is needed on just the one affected breast, and then take a little time to consider CPM and other options, once the treatment is completed.
The authors concluded that:
"The use of contralateral prophylactic mastectomy in the United States more than doubled within the recent 6-year period of our study. Prospective studies are needed to understand the decision-making processes that have led to more aggressive breast cancer surgery."
"Increasing Use of Contralateral Prophylactic Mastectomy for Breast Cancer Patients: A Trend Toward More Aggressive Surgical Treatment."
Todd M. Tuttle, Elizabeth B. Habermann, Erin H. Grund, Todd J. Morris, Beth A. Virnig.
Journal of Clinical Oncology Early Release, published online ahead of print, Oct 22 2007
Click here for Abstract.
Written by: Catharine Paddock