Atypical ductal hyperplasia cases decreased with reduction in postmenopausal HT

Rates of atypical ductal hyperplasia have decreased over the past decade — a finding that may be attributed to the decreasing rate of postmenopausal hormone therapy use.

Researchers have confirmed that postmenopausal HT use is associated with atypical ductal hyperplasia, a known risk factor for breast cancer. Using data on screening mammograms done between 1996 and 2005 from mammogram registries in the Breast Cancer Surveillance Consortium, the researchers found more than 2.4 million screening mammograms. These mammograms were associated with 1,064 biopsies with atypical ductal hyperplasia, 853 breast cancers with atypical ductal hyperplasia and 8,161 cancers with no atypical ductal hyperplasia.

During the study period, the rate of postmenopausal HT use decreased from 35% to 11%. At the same time, atypical ductal hyperplasia rates decreased from 5.5 per 10,000 mammograms in 1999 to 2.4 per 10,000 mammograms in 2005. In addition, rates of cancer with atypical ductal hyperplasia reduced from 4.3 per 10,000 mammograms in 2003 to 3.3 per 10,000 in 2005.

Atypical ductal hyperplasia was most common in women with a family history of breast cancer (OR=1.25; 95% CI, 1.04-1.50), perimenopausal women (OR=1.75; 95% CI, 1.07-2.73) and current postmenopausal HT users (OR=1.54; 95% CI, 1.29-1.83). Cases of cancer with atypical ductal hyperplasia were highest among women aged 70 to 79 years (OR=1.84; 95% CI, 1.87-2.31), women with a family breast cancer history (OR=1.63; 95% CI, 1.36-1.95) and those women currently using HT (OR=1.38; 95% CI, 1.14-1.67).

Cancers associated with atypical ductal hyperplasia were more likely to be ductal carcinoma in situ and were more likely to be grade 1 or 2 compared with cancer without atypical ductal hyperplasia.

Menes TS. Cancer Epidemiol Biomarkers Prev. 2009;18:2822-2828.