FRIDAY, Jan. 10, 2003 (HealthDayNews) -- In a finding that could change how doctors identify candidates for a double mastectomy, new research has found the risk of breast cancer varies dramatically from one breast to the other.
Researchers studied 252 women with a type of breast lesion called atypical lobular hyperplasia, which is believed to be a precursor to cancer.
Fifty of the women, or 20 percent, developed breast cancer. Of those, 34 cancers, or 68 percent, occurred in the same region of the same breast where the lesions were found earlier.
Makes sense, right?
Then consider this: Many doctors believe atypical lobular hyperplasia in one breast means a much higher rate of breast cancer developing in either breast, says Dr. David L. Page, lead study author and a professor of pathology and preventive medicine at Vanderbilt University School of Medicine in Nashville.
For that reason, doctors often recommend that women undergo a double mastectomy, or removal of both breasts, to prevent breast cancer down the line.
"We've been guided by the belief that this type of lesion is a marker for increased risk anywhere in either breast," Page says. "We decided 30 years ago we were going to do a double mastectomy -- all or nothing --- but that approach is not totally supported by the facts."
The study appears in the Jan. 11 issue of The Lancet.
In an accompanying commentary, Dr. Sunil Lakhani of the Institute of Cancer Research and Royal Marsden Hospital in London says the study provides "evidence to counteract the myth that the risk of invasive carcinoma after a diagnosis of lobular in situ neoplasia is equal in both breasts."
Dr. Jay Brooks, chief of oncology and hematology at the Ochsner Clinic Foundation in Baton Rouge, La., says the study raises interesting questions about the best course of action when dealing with these lesions.
"It's a very provocative finding, and that's good," Brooks says. "But it's still a relatively small number of patients to make a definitive statement about it."
Furthermore, Brooks adds, not every woman developed breast cancer in the same breast. According to the study, 12 women, or 24 percent, got breast cancer in the other breast. In 2 percent, the side was unknown.
Until recently, doctors looked for two major types of precancerous breast lesions, Page says.
One is ductal carcinoma in situ, which previous research has shown means a high risk of developing cancer in that location of the breast, Page says.
The second is lobular carcinoma in situ, which doctors believed meant a high risk of getting breast cancer anywhere in either breast, he says. But this assumption was based on the faulty interpretation of data, he says.
Atypical lobular hyperplasia is sometimes called lobular carcinoma in situ. In fact, the two are distinct types of lesions and shouldn't be lumped together, Page says.
Both are benign breast diseases. But atypical lobular hyperplasia lesions tend to be smaller, he says.
Women with lobular carcinoma in situ may have an increased risk of breast cancer in both breasts. And therefore, a double mastectomy may be what's called for.
But atypical lobular hyperplasia may be something "in between" the ductal and lobular carcinomas in situ. Women with atypical lobular hyperplasia have an increased risk of developing breast cancer -- if not in the precise location of the lesions, in the same region of the same breast, Page says.
That means there may be no need for a double mastectomy as a preventive measure, he says. Instead, a single mastectomy, or even a partial mastectomy, may be all that's necessary.
In a partial mastectomy, surgeons remove the densest part of the breast, where cancer is prone to develop. Surgeons are still working on developing a more effective method, he says.
"There's going to be a lot of controversy here," Page says. "I think it should change medical practice."
Although there are no precise statistics, about 2 percent to 4 percent of women who get biopsies are diagnosed with atypical lobular hyperplasia. Those at highest risk are premenopausal women between the ages of 40 and 60, he says.
Brooks says there is more to consider than just the type of lesion a woman has when recommending for or against a mastectomy. Her family history of breast and ovarian cancer, her genetic risk, and her emotional state play a role.
Some women insist on the mastectomy because they are so fearful of cancer, he says.
Using the chemotherapy drug tamoxifen is also a means of reducing breast cancer risk in women prone to it, he says.
"What this study is showing is that breast cancer is a disease that in many cases starts off with precancerous lesions that we can use as a marker and do something about it," Brooks says.
More information
For more information about breast cancer and tumor types, visit the American Cancer Society or the National Cancer Institute.
