A new study from the Mayo Clinic found that women with atypical hyperplasia face a much higher risk of breast cancer than women without the condition. Based on their findings, the authors of this study said women with this condition should also be screened with magnetic resonance imaging (MRI).
These researchers added that these women may also want to consider anti-estrogen medications. These medications have been shown to lower the risk of developing breast cancer by 50 percent or more, according to the research.
Lynn C. Hartmann, MD, an oncologist at the Mayo Clinic in Rochester, MN, led this study.
"We need to do more for this population of women who are at higher risk, such as providing the option of MRI screenings in addition to mammograms and encouraging consideration of anti-estrogen therapies that could reduce their risk of developing cancer," Dr. Hartmann said in a press release.
A mammogram may detect excessive growth of cells in the breast called hyperplasia. Mild hyperplasia does not raise cancer risk, but moderate and abnormal hyperplasia may serve as a warning sign.
Dr. Hartmann and colleagues followed 698 women with atypical hyperplasia. They had been biopsied at the Mayo Clinic between 1967 and 2001. After an average follow-up of 12.5 years, 143 of these women, or about 20 percent, had developed breast cancer.
At 25 years after biopsy, 25 to 30 percent of these women had developed breast cancer.
Dr. Hartmann and team noted that cancer risk increased with the extent of the atypical hyperplasia. They measured the extent by lesions or foci found in biopsies. A focus is a breast lesion smaller than 5 millimeters. At 25 years after the biopsy, 47 percent of women with three or more foci of atypical hyperplasia had developed breast cancer. Among women who had only one focus, 24 percent developed cancer.
These researchers concluded that the estimated 100,000 women who are diagnosed each year with atypical hyperplasia are likely to benefit from intense screening and use of medications to reduce risk.
Hyperplasia is a benign overgrowth of cells that line the ducts or lobules (the glands that make milk) inside the breast. While a mammogram may show signs of this cell abnormal cell growth, a biopsy (taking a tissue sample) can confirm the condition. Hyperplasia itself isn’t cancerous, but in time these cells may keep dividing and become more abnormal and transition to cancer.
Many women with atypical hyperplasia, however, are not taking potentially helpful medications like tamoxifen (brand name Nolvadex), Dr. Hartmann and team noted. They indicated that this may be due to doctors who have not had solid estimates of breast cancer risk to guide them.
The American Cancer Society also says patients who are high risk should undergo MRI screening.
“Breast cancer will not develop in the majority of these women [with atypical hyperplasia],” Dr. Hartmann and team said. “Even among those in whom breast cancer does develop, the diagnosis may occur at an age at which their risk of death from other causes is higher than their risk of death from breast cancer.”
This study was published Dec. 31 in the New England Journal of Medicine.
Grants from the National Cancer Institute and the National Center for Advancing Translational Sciences funded this research. The authors did not provide conflict of interest disclosures with the available study.