Study finds women hesitant to take tamoxifen as preventive measure


BOSTON -- Researchers have found that due to concerns about risks and side effects, women at high risk for developing breast cancer are choosing not to take tamoxifen, the first and only drug approved by the U.S. Food and Drug Administration (FDA) for the prevention of breast cancer. The study appears in the December 14, 2004 issue of The Journal of Clinical Oncology.

"While the availability of tamoxifen is a significant advance in breast cancer prevention, it also presents a complicated decision for women at high risk for developing the disease," says the study's lead author Sharon Bober, PhD, staff psychologist at Beth Israel Deaconess Medical Center (BIDMC) and Dana-Farber Cancer Institute (DFCI) and Clinical Instructor in the Department of Psychiatry at Harvard Medical School.

"Our study underscores the need [for medical professionals] to address psychological factors that may influence decision-making, in order to help women feel confident and satisfied with their treatment choice."

Tamoxifen belongs to a class of drugs known as selective estrogen receptor modulators or SERMS, which work by preventing the hormone estrogen from binding to breast cancer cells, and thereby helping to halt the growth of these cancerous cells.

Prophylactic use of tamoxifen has been shown to reduce the risk of both invasive and non-invasive breast cancer by nearly 50 percent. However, tamoxifen also poses a number of risks and side effects: the risk of developing endometrial cancer, blood clots, and cataracts can increase with the use of tamoxifen, and menopausal symptoms such as hot flashes and night sweats can worsen.

Researchers at BIDMC evaluated both medical and psychological factors involved in decision making among 129 women who had a five-year risk of developing cancer of 1.7 percent or greater and were therefore deemed eligible to receive tamoxifen as a preventive measure. The subjects were counseled by their physicians about the possible risks and benefits of tamoxifen therapy, and were asked to complete questionnaires assessing demographics, personal and family health history and emotional factors including level of distress, anxiety about breast cancer and optimism about future outcomes. Post-menopausal women were given the option of either taking tamoxifen or enrolling in the STAR trial, a randomized study comparing five years of use of tamoxifen and raloxifene, another drug in the same class as tamoxifen.

Researchers followed up with study participants at two and four months to assess their treatment decision and their satisfaction with that decision. After two months, 29 percent of study participants had decided to take tamoxifen; 27 percent had opted to enroll in the STAR trial; 24 percent had declined any treatment; and 20 percent remained undecided. After four months, some participants had changed their decision, nearly all of whom had opted against treatment after initially choosing the treatment. A total of 51 percent chose to either take tamoxifen or to enroll in the STAR trial, 35 percent declined treatment and 14 percent remained undecided.

Researchers assessed the influence of health-related variables on participants' decision-making, finding that contrary to expectations, a family history of breast cancer did not increase the likelihood that women would choose to take tamoxifen. However, personal history, such as abnormal biopsy, was highly correlated with the decision to take tamoxifen. Physician advice also influenced decision-making, with women who received a recommendation from their doctors more likely to take the medication.

Researchers also found that perception of risk and a lack of information influenced decisions about tamoxifen:

  • Women in the study who declined treatment were more likely to report a fear of side effects and believe that tamoxifen would not be an effective prevention strategy;
  • Women who felt uninformed about their options were more likely to remain undecided; and,
  • Women who reported higher levels of anxiety about cancer and who perceived themselves to be at greater risk for developing breast cancer were more likely to choose tamoxifen.

Researchers noted that previous studies suggest that dissatisfaction with their decision may lead some women to prematurely discontinue treatment, and underscored the need for more patient education and improved physician-patient communication to help women make more informed decisions, according to Bober.

"This study highlights the complexity of making important medical decisions, and underscores the need for improved patient-physician communication to help patients weigh the risks and benefits of therapy," explains Bober. "Women are willing to make great effort and engage in difficult decision-making in order to reduce their risk of developing breast cancer. But even the best available preventive treatments were not sufficient to persuade women to use them."

Co-authors include Nadine Tung, MD, Rosemary Duda, MD, and Lizbeth Hoke, PhD, of Beth Israel Deaconess Medical Center; and Meredith Regan, PhD, of Dana-Farber Cancer Institute.

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Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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