Strategies to improve adherence to interventions
Participants will follow the recommendations of the study protocol, including the doses of RT and tamoxifen. Because the study is divided into two arms, adjuvant RT and adjuvant low-dose tamoxifen, deviations in the RT or tamoxifen doses will not be allowed. If participants refuse the assigned treatment, they will remain in the trial’s intention-to-treat analysis, unless they unambiguously refuse.