Five years of tamoxifen confers a significant benefit beyond 1-2 years of tamoxifen, so physicians should ask patients about side effects, other prescriptions, and beliefs about tamoxifen and should educate them about the benefits of completing adjuvant therapy.

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.

Attention to nonadherence among older women at risk of discontinuation, particularly those receiving BCS without radiotherapy, might improve breast cancer outcomes for these women.