(RxWiki News) About one in 10 breast biopsies detect some type of breast tissue abnormality. Researchers have discovered two different tissue changes that tended to increase breast cancer risks in the same way.
The two breast tissue abnormalities studied were atypical ductal hyperplasia (ADH) and atypical lobular hyperplasia (ALH). While ADH and ALH have been thought to impact a woman's breast cancer risks differently, this research suggested that they both increased the odds of developing more serious forms of breast cancer.
This study may change how doctors manage these conditions.
"If you notice any breast tissue changes, see your doctor."
Lynn C. Hartmann, MD, professor of oncology at the Mayo Clinic in Rochester, Minn, led this study, which examined the outlook for women with biopsy-diagnosed ADH and ALH.
Atypical ductal hyperplasia develops in the breast ducts, which are the vessels that carry a mother’s milk to her baby. Atypical lobular hyperplasia starts in the lobules, which make the mother’s milk. Up until now, physicians have thought ADH and ADL behaved differently.
ADH has been thought to be a pre-cancerous condition and to increase the odds of breast cancer developing in the same breast, while ALH was thought to increase the chances of breast cancer appearing on both sides in areas different from the biopsy location.
Dr. Hartmann said in a statement, “Most have considered ADH a direct precursor to breast cancer, arguing that it requires complete surgical excision while others have maintained that ALH serves as an indicator of heightened and equal risk of breast cancer across both breasts and does not need complete surgical removal. Moreover, some experts have argued that women with atypia [abnormal cells] develop ‘better risk’ breast cancers, meaning low-grade cancers with a good prognosis.”
This research team identified 698 women from the Mayo Benign Breast Cohort with biopsy-confirmed atypia. A total of 330 of participants had ADH, 327 had ALH and 32 had both. The women were followed for an average of 12.5 years, during which 143 (20.4 percent) of them developed breast cancer.
Here’s what the researchers learned about these breast cancers:
- Breast cancers developing within 5 years of the biopsy were more likely to occur in the same breast as the atypia compared to those developing more than 5 years removed from the atypia
- The risk of cancer developing in the same breast as the abnormal cells was especially high in the first five years after detection and remained elevated in both breasts long term.
- Among all the women with abnormal cells, four times more women developed invasive cancers that have spread beyond the original site than in situ cancers, which have not spread. Specifically, 81 percent of the breast cancers were invasive, while 19 percent were ductal carcinoma in situ (DCIS), which has not spread beyond the duct.
- With ALH, 87 percent of later breast cancers were invasive, and 13 percent were DCIS.
- For women with ADH, 78 percent of the cancers that developed later were ductal and 22 percent were lobular.
- For women with ALH, 77 percent of the cancers that developed after the atypia detection were ductal and 23 percent were lobular.
- Both ADH and ALH resulted in invasive ductal cancers, of which 69 percent were of intermediate or high grade (measure of aggressiveness).
Based on these findings, the researchers suggested that ALH may be a breast cancer precursor, as well as being an elevated risk factor for the disease.
“If a woman has a breast biopsy and if it shows atypia, it might be wise for her to be seen at a breast center for recommendations about surveillance and preventive therapy options,” Dr. Hartmann said. “We hope these data will further help clinicians make informed decisions for breast atypia management strategies.”
This study was published January 30 in Cancer Prevention Research, a journal of the American Association for Cancer Research.
This study was funded by the Mayo Clinic Breast Cancer Specialized Program of Research Excellence (SPORE) grant from the National Institutes of Health and Susan G. Komen.
One of the authors, Richard J. Santen, MD, disclosed a financial relationship with Pfizer. No other conflicts of interest were reported.