Based on age and risk, an estimated 10 million women in the United States may be eligible for an agent aimed at preventing breast cancer, but chemoprevention is underutilized. Fewer than 5% of women at high risk who are offered tamoxifen for chemoprevention agree to take the drug, partly due to inadequate time for counseling, insufficient knowledge about risk-reduction strategies, and concerns about side effects, according to Parijathan S. Sivasubramanian, MD, of Columbia University College of Physicians and Surgeons, New York.1
Dr. Sivasubramanian led one of two studies examining the factors that influence the uptake of chemoprevention. The other was presented at the meeting by Erin W. Hofstatter, MD, of Yale University School of Medicine, New Haven, Connecticut.2
‘Richer and Wiser’ Women
Dr. Hofstatter reported that being “richer and wiser” was a factor in the acceptance of chemoprevention, based on information from the National Health Interview Survey, a population-based survey conducted annually by the Centers for Disease Control.
In 2010, the survey was conducted on 10,959 women ≥ 35 years old, of whom 0.21% reported taking chemoprevention. Bivariate analysis revealed several factors associated with uptake: age, race/ethnicity, education, insurance status, income, and geographic region.
“Interestingly, the use of breast MRI [magnetic resonance imaging], family history, and personal risk perception were not associated,” Dr. Hofstatter indicated. “On the multivariate analysis, education and income remained independent predictors of chemoprevention use. Risk perception and family history did not appear to correlate.”
Compared to women with less than a high school degree, the odds ratios for chemoprevention were 1.86 for high school education, 1.86 for some college, 3.23 for a Master’s degree and 25.2 for doctorate degrees (P < .0001). Compared to an income < $35,000, income ≥ $100,000 carried an odds ratio of 3.78 (P = .03).
“These findings highlight the potential disparities in access to appropriate chemoprevention options,” Dr. Hofstatter commented. “Improved education and counseling of those women at increased risk of breast cancer is greatly needed.”
Breast Clinic Involvement
The study reported by Dr. Sivasubramanian was a survey of consecutive women seen for initial consultation at the breast clinic of Columbia University Medical Center. Of 1,448 enrolled between 2007 and 2013, 416 were deemed at high risk or diagnosed with ductal carcinoma in situ (DCIS), 316 of whom were offered chemoprevention. Antiestrogen drugs (primarily tamoxifen) were adopted by 162 women, while 154 declined chemoprevention.
She attributed the high rate of acceptance—about 50%—to the fact that the participants attended a breast clinic where they received accurate and comprehensive information about chemoprevention.
Antiestrogen use was higher among women with DCIS (57.4%), compared to those with lobular carcinoma in situ or BRCA mutations (20.4%) and those with a 5-year Gail risk ≥ 1.67% (22.2%). In the multivariate analysis, only breast cancer risk category was an independent predictor of antiestrogen use.
But a number of other things factored into a woman’s decision to either accept or decline chemoprevention, she said. Most important was knowledge about another woman’s experiences with tamoxifen, raloxifene (Evista), or aromatase inhibitors, cited by more than half the women as a factor. Results from clinical trials, conversations with friends and family, information from a health-care provider, and information from reputable websites were each cited by about 30% of the women as important in decision-making.
She noted that concerns about bone fractures with aromatase inhibitors were cited as a potential side effect five times more often (67%) than arthritis. With tamoxifen, women were most concerned about blood clots (44%) and uterine cancer (31%). The main concern with raloxifene was also blood clots (80%).
Dr. Sivasubramanian suggested that a term other than “chemoprevention” be used in conversations with high-risk women, based on the perception among some participants that these agents would cause alopecia. “Most women don’t understand what chemoprevention is,” she said. ■
Disclosure: Dr. Sivasubramanian and Hofstatter reported no potential conflicts of interest.
References
1. Sivasubramanian PS, Reimbers LL, Greenlee H, et al: Uptake of breast cancer chemoprevention among high-risk women and those with ductal carcinoma in situ. 2013 San Antonio Breast Cancer Symposium. Abstract P5-13-01. Presented December 13, 2013.
2. Hofstatter EW, Lannin D, Horowitz N, et al: Richer and wiser: Factors correlated with chemoprevention use in the United States. 2013 San Antonio Breast Cancer Symposium. Abstract P5-13-05. Presented December 13, 2013.
