A new US study has sought to help women who have been treated for breast cancer in one breast to make a better informed decision about whether to have a preventive mastectomy to remove the unaffected breast by identifying which types of patients and tumors present the highest risk of developing cancer in the second breast.
The study was the work of Dr Kelly K Hunt and colleagues at the University of Texas MD Anderson Cancer Center in Houston, and colleagues, and is to be published in the March 1, 2009 issue of CANCER, a peer-reviewed journal of the American Cancer Society.
Having breast cancer in one breast increases a woman’s chances of getting it in the second breast, either at the same time or later. Finding out which women are most at risk of developing cancer in the other breast could help patients make better decisions about preventive treatment, such as whether to surgically remove the other breast.
Women who choose to have a mastectomy to remove the unaffected breast currently do so for a number of reasons: their doctor advises it, they are scared of another cancer diagnosis, they want both breasts to look the same, and/or because having cancer in the second breast runs in the family.
However, there is not enough research evidence to help women make this choice; all we know is that most breast cancer patients do not necessarily benefit in terms of extending survival. It would help if we knew which women were at the highest risk of develeloping cancer in the second breast: what is it about the patient, and the type of cancer in the first breast, that makes this more likely?
To attempt an answer to this question, Hunt and colleagues studied 542 patients who had breast cancer diagnosed in one breast (unilateral breast) and decided to have this and the other breast (contralateral prophylactic mastectomy) removed between 2000 and 2007. They then examined tissue specimens of the removed second breast and found that 25 of the patients (5 per cent) had breast cancer in the removed second breast and 82 (15 per cent) had abnormal cells that could signify higher risk of developing breast cancer.
Hunt and colleagues also looked at all the information they had about the women’s breast cancers and their clinical records, and found there were three independent factors that linked most closely to the likelihood of having cancer in the second breast. These were: when the cancer cells were particularly invasive (this can be assessed from their histologic characteristics); when the cancer occurred in more than one quadrant of the breast; and when the patient had a 5-year Gail risk of 1.67 or more (the Gail risk uses medical history, age, race, and other information to assess a healthy woman’s risk of developing cancer).
They also found that abnormal cells in the second breast were more likely to be linked to women aged 50 and over at the first diagnosis, or who had moderate to high risk cells in the affected (first) breast.
Speaking to the press, Hunt said:
“Our goal is to help women make more informed decisions, based on their individual case rather than the general population, about whether to have this aggressive and irreversible procedure.”
“Women often consider it not because of their doctor’s recommendation, but out of fear their cancer will return,” she told the Houston Chronicle.
Many doctors think that radical mastectomies are often performed unnecessarily and they can also develop complications that have nothing to do with the cancer.
Dr Todd Tuttle, a surgical oncologist at the University of Minnesota and author of a study published in 2007 that revealed the steep rise in women opting for double mastectomy, said he hoped this study will help to bring down the numbers.
“Either because it confirms statistics that patients’ overall risk of the cancer returning in the other breast is actually low or because it will lead to a tool that shows their specific risk is low, it should send a loud message that women not overreact to their diagnosis,” he told the Chronicle.
“Predictors of contralateral breast cancer in patients with unilateral breast cancer undergoing contralateral prophylactic mastectomy.”
Min Yi, Funda Meric-Bernstam, Lavinia P. Middleton, Banu K. Arun, Isabelle Bedrosian, Gildy V. Babiera, Rosa F. Hwang, Henry M. Kuerer, Wei Yang, and Kelly K. Hunt.
CANCER Print Issue Date: March 1, 2009; Published Online: January 26, 2009.
DOI: 10.002/cncr.24129
. Click here for CANCER journal home page.
Sources: ACS, Houston Chronice.
Written by: Catharine Paddock, PhD