Women with atypical hyperplasia are at higher risk of breast cancer

December 31, 2014, Mayo Clinic
Mammograms showing a normal breast (left) and a cancerous breast (right). Credit: Wikipedia.

Women with atypical hyperplasia of the breast have a higher risk of developing breast cancer than previously thought, a Mayo Clinic study has found. Results of the study appear in a special report on breast cancer in the New England Journal of Medicine.

Atypical hyperplasia of the breast is a precancerous condition found in about one-tenth of the over 1 million with benign findings performed annually in the United States. Viewed under a microscope, atypia contains breast cells that are beginning to grow out of control (hyperplasia) and cluster into abnormal patterns (atypical). Atypia lesions are considered benign, but by its risk and appearance and genetic changes, they exhibit some of the early features of cancer.

Data from hundreds of women with these benign lesions indicate that their absolute risk of developing grows by over 1 percent a year. The study found that after five years, 7 percent of these women had developed the disease; after 10 years, that number had increased to 13 percent; and after 25 years, 30 percent had breast cancer.

The finding places the more than 100,000 women diagnosed each year with atypical hyperplasia—also known as atypia—into a high-risk category, where they are more likely to benefit from intense screening and use of medications to reduce risk.

"By providing better risk prediction for this group, we can tailor a woman's clinical care to her individual level of risk," says Lynn Hartmann, M.D., an oncologist at Mayo Clinic and lead author of the 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."

Previous research has shown that women with atypia have a fourfold to fivefold increased "relative risk"—meaning that they are four to five times more likely to develop breast cancer than women who don't have these lesions. But few studies have had the patient numbers and follow-up time to report the patients' "absolute risk"—the chance that she will develop breast cancer over a certain period of time.

To clearly define this risk, the Mayo Clinic team followed 698 women with atypia who had been biopsied at Mayo Clinic between 1967 and 2001. They reviewed pathology and medical records, and used patient follow-up questionnaires to determine which women developed breast cancer and when. The researchers found that after an average follow-up of 12.5 years, 143 women had developed the disease.

Importantly, the Mayo findings were validated by researchers at Vanderbilt University using biopsies from a separate cohort of women with atypia. Both data sets revealed that at 25 years following biopsy, 25 to 30 percent of these women had developed breast cancer.

The Mayo team had previously showed that two common statistical risk prediction models (the BCRAT and the IBIS models) performed poorly in women with atypical hyperplasia, underscoring the need to provide alternative approaches for predicting risk in this population.

"Instead of relying on a statistical model, our study provides actual data of breast cancer cases that occurred in a population of women with atypia. These absolute risk data are preferable to a hypothetical model," says Amy Degnim, M.D., co-lead author and a breast surgeon at Mayo Clinic.

The researchers were able to give an even more accurate estimate of risk by incorporating information from a patient's pathology specimen. They found that as the extent of atypia in a biopsy increased, as measured by the number of separate atypia lesions or foci, so did the woman's risk of developing breast cancer. For example, at 25 years post-biopsy, 47 percent women with three or more foci of atypia in the biopsy had developed breast cancer, compared to only 24 percent of women with one focus.

Based on these results, the research team recommends that women with atypical hyperplasia be recognized as having significantly increased lifetime risk of breast cancer and thus be candidates for screening MRI. Moreover, anti-estrogen medications like tamoxifen have already been tested in clinical trials in women with atypia and shown to lower their risk of breast cancer by 50 percent or more. Yet, Dr. Degnim says, many with atypia are not taking the medications, in part because they and their physicians have not had solid estimates of their to guide them.

Explore further: New data contradict current recommendations for management of breast biopsy abnormalities

Related Stories

New data contradict current recommendations for management of breast biopsy abnormalities

January 30, 2014
Contrary to existing understanding, long-term follow-up of patients with two types of breast tissue abnormalities suggests that both types of abnormalities have the same potential to progress to breast cancer, according to ...

What to know if breast cancer runs in your family

October 7, 2014
Breast cancer is the second leading cause of death from cancer in women. A woman's lifetime risk of developing breast cancer is 12 percent (1 of every 8 women). Breast cancer risk is higher among women whose close blood relatives ...

Cancer risk for African-American women with benign breast disease factors, study finds

February 11, 2013
A Wayne State University researcher has identified characteristics in benign breast disease associated with future cancer risk in African-American women.

New model of follow up for breast cancer patients

November 21, 2014
Public health researchers from the University of Adelaide have evaluated international breast cancer guidelines, finding that there is potential to improve surveillance of breast cancer survivors from both a patient and health ...

Recommended for you

Cancer immunotherapy might benefit from previously overlooked immune players

September 20, 2018
Cancer immunotherapy—efforts to boost a patient's own immune system, allowing it to better fight cancer cells on its own—has shown great promise for some previously intractable cancers. Yet immunotherapy doesn't work ...

What can salad dressing tell us about cancer? Think oil and vinegar

September 20, 2018
Researchers led by St. Jude Children's Research Hospital scientists have identified another way the process that causes oil to form droplets in water may contribute to solid tumors, such as prostate and breast cancer. The ...

Novel biomarker found in ovarian cancer patients can predict response to therapy

September 20, 2018
Despite months of aggressive treatment involving surgery and chemotherapy, about 85 percent of women with high-grade wide-spread ovarian cancer will have a recurrence of their disease. This leads to further treatment, but ...

Testing fluorescent tracers used to help surgeons determine edges of breast cancer tumors

September 20, 2018
A team of researchers with members from institutions in The Netherlands and China has conducted a test of fluorescent tracers meant to aid surgeons performing tumor removal in breast cancer patients. In their paper published ...

New way to target advanced breast cancers

September 20, 2018
A cytokine signature found in certain kinds of breast cancer cells can not only serve as a diagnostic tool for HER2-negative cancers but also offer an effective treatment target.

Understanding epilepsy in pediatric tumors

September 20, 2018
Pediatric brain tumors are characterized by frequent complications due to intractable epilepsy compared to adult brain tumors. However, the genetic cause of refractory epilepsy in pediatric brain cancer has not been elucidated ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.