Tamoxifen beyond 5 years--patients' decisions regarding entry to the aTTom trial

The aim of this study was to assess among a population of women who had taken adjuvant tamoxifen for 5 years, how many were prepared to enter a randomised trial looking at the duration of tamoxifen treatment and what was the preference of those who declined trial entry. There is uncertainty as to the optimum duration of adjuvant tamoxifen and this is the subject of the aTTom (adjuvant Tamoxifen Treatment offer more?) trial in which patients are randomised to continue or stop tamoxifen after 5 years. Patients have been recruited to the aTTom trial in Dundee since 1996 and a record has been kept of all the patients with whom the trial was discussed. Patients who declined trial entry were allowed to choose whether to electively stop or continue tamoxifen. 306 patients were eligible for trial entry of whom 171 (56%) consented to randomisation (82 to continue and 89 to stop). Amongst the 135 (44%) who declined randomisation, 28 (21%) elected to stop tamoxifen treatment, 90 (67%) elected to continue and in 17 (13%) their decision was unclear. These results illustrate that patients eligible for the aTTom trial share our clinical equipoise. A majority (56%) of patients were agreeable to randomisation, but among those who declined, some (67%) preferred to continue, some (21%) to stop tamoxifen. This trial is unusual in that the patients have already experienced the treatment options, so the patients' preferences reflect a truly informed choice.