© 2005-2012 American Society of Clinical Oncology (ASCO). All rights reserved worldwide.
Posted online October 22, 2007, on www.jco.org.
A new study reports a 150 percent increase between 1998 and 2003 in American women opting to have both breasts removed when cancer has been found in only one breastâa procedure called "contralateral prophylactic mastectomy (CPM)." This is the first study to examine this issue on a national level. The study was published in the Journal of Clinical Oncology (JCO).
The study's authors cautioned that this aggressive strategy may be unnecessary: surgery carries inherent risks; most patients will never develop cancer in the second breast; and the risk of cancer spreading to other parts of the body is often higher than the risk that cancer will be found in the second breast. There are very little data showing that CPM improves overall survival.
The researchers reviewed the treatment of patients with cancer diagnosed in one breast between 1998 and 2003 in the United States. Among 152,755 women diagnosed with stage I, II, or III breast cancer during this period, 59,460 underwent a single mastectomy; 4,969 other women, who were candidates for a single mastectomy, chose to have CPM as well. The CPM rate among those who were candidates for a single mastectomy rose from 4.2 percent in 1998 to 11 percent in 2003.
The authors cited several possible reasons for the increased rate of CPM, including greater public awareness about the genetics of breast cancer and more frequent testing for mutations in BRCA genes, which increase contralateral breast cancer risk (although this study did not examine patients' BRCA status). Additionally, less invasive mastectomy approaches and improved breast reconstruction techniques may persuade more women to have both breasts removed at the same time.
What Does This Mean for Patients?
Many women make the decision to have CPM quickly and at a vulnerable time. Researchers want to learn more about why the increase in the rate of CPM is occurring and use this information to counsel women about the availability of less invasive yet equally effective options.
In the meantime, women who are going to have a mastectomy for cancer in one breast should remember that they may benefit from waiting and treating just the known breast cancer first, and then considering other options later, after their initial treatment is completed.