Improving practice to eliminate high risk and prevent breast cancer

Fewer than 30% of the women in the U.S. with abnormal, benign lesions known as atypical hyperplasia (AH) and lobular carcinoma in situ (LCIS) – a condition that significantly increases their risk of developing breast cancer – take advantage of available preventive therapies that can significantly reduce that risk.

In an effort to improve those rates, Abenaa Brewster, M.D., professor of Clinical Cancer Prevention, worked with colleagues to implement a performance improvement program in MD Anderson’s Cancer Prevention Center (CPC). That program, reported recently in Cancer Prevention Research, resulted in an increase in the use of preventive anti-estrogen therapies such as tamoxifen and raloxifene from 44% to more than 80%.

“We have evidence-based guidelines for ways in which we can practice to reduce the incidence of breast cancer,” said Brewster, lead author of the study. “And one that isn’t really being used as effectively as it should be is the administration of preventive therapy to women who are at high risk. That’s low hanging fruit.”

Driven to reduce the incidence of breast cancer, this work was funded by MD Anderson’s Breast Cancer Moon Shot™, part of the Moon Shots Program™, a collaborative effort to accelerate the development of scientific discoveries into clinical advances that save patients’ lives.

“If we can get more of these women to take preventive therapy, we can prevent more breast cancers,” Brewster said.

Among women receiving screening mammograms, AH/LCIS are premalignant lesions found in approximately 10% of biopsies with benign findings. The lifetime risk of developing breast cancer is greater than 20% for women with these conditions, but clinical trials suggest preventive therapies could lower that risk by as much as 75%.

Despite recommendations by the National Comprehensive Cancer Network, most women with AH/LCIS are not taking preventive medications. Reasons for the inaction include doctors not advocating strongly for these therapies and patients’ fear of side effects.

Strengthening the recommendation from healthcare providers was a key component of the MD Anderson program. Through comprehensive education, training and internal audits, physicians in the CPC were able to standardize the strong recommendation to their patients, explained Brewster.

In addition, it was important to provide accurate information to patients about possible, but rare, side effects associated with these medications. The most frequent of which include hot flashes, vaginal discharge/dryness and joint pain.

“When we counsel women about these medications and we counsel them about side effects, we often fail to convey that the majority of women don’t experience any side effects,” said Brewster. “We also don’t do as good a job at reassuring women that if they have side effects, we’re going to be actively engaged in helping them to manage those symptoms.”

Tamoxifen also is associated with more serious, though very rare, side effects, including increased risk of blood clots and uterine cancer. However, women must be counseled that their risk of developing breast cancer without tamoxifen is much higher than the risks of developing these conditions while taking tamoxifen, explained Brewster.

“Overall, these medications will prevent more cancers than cause cancers,” Brewster said. “That’s an important message to get across to women.”

Through concerted efforts on the part of all providers in the CPC, the performance-improvement program more than doubled the percentage of MD Anderson patients in this group who are taking preventive therapies.

Brewster acknowledges that this approach may not be feasible across all institutions, but she hopes to begin working with MD Anderson’s Physician Network to bring the system-level strategy to other clinics and evaluate its effectiveness in those settings.

The goal remains to encourage more women at high risk of developing breast cancer to consider these preventive medications and ultimately prevent breast cancers from occurring wherever possible.

In addition to Brewster, co-authors on the MD Anderson study include:

Priya Thomas, M.D., Powel Brown, M.D., Ph.D., Robin Coyne, and Therese Bevers, M.D. – all from Clinical Cancer Prevention; Biostatistics’ Yuanquing Yan, Ph.D., and Kim-anh Do, Ph.D.; Cristina Checka, M.D., of Breast Surgical Oncology; and Lavinia Middleton, M.D., of Pathology.