Purpose: To investigate the patterns and predictors of tamoxifen discontinuance throughout a 2-year period in a cohort of women 65 years or older with newly diagnosed, estrogen receptor (ER)-positive breast cancer, focusing on the role of patients' beliefs about the risks and benefits of tamoxifen therapy.
Subjects and methods: We enrolled a convenience sample of women cared for in four geographic regions of the United States with stage 1 (>/= 1 cm), stage II, or stage IIIA disease; no prior history of breast cancer; and no simultaneously diagnosed second primary breast cancer. Data sources included medical records and telephone interviews with patients at 3, 6, 15, and 27 months following definitive surgery.
Results: Of the 597 women with ER-positive tumors, 516 women (86%) were prescribed tamoxifen, and of these, 88 (17%) stopped taking tamoxifen during the 2-year follow-up period. Of the women who stopped taking tamoxifen, the majority (68%) took it for less than 1 year. Women with neutral or negative beliefs about the value of tamoxifen (3.0; 95% CI, 1.6 to 5.6) and those with positive nodes (odds ratio = 2.5; 95% CI, 1.0 to 6.3) were more likely to discontinue tamoxifen therapy.
Conclusion: How women with early-stage breast cancer perceive the risks and benefits of tamoxifen therapy seems critical for sustaining adherence to adjuvant tamoxifen therapy. Interventions designed to educate women about the benefits and risks of tamoxifen therapy may help to reduce discontinuance.