39P A validation study of a self-testing capillary kit, the rhelise kit for therapeutic dose monitoring (TDM) of tamoxifen, Z-endoxifen, and 4-hydroxytamoxifen in breast cancer patients

Tamoxifen is an effective drug reducing the risk of dying from breast cancer. This study aims to validate and feasibility serial assessments, including therapeutic monitoring tamoxifen (TAM), 4-hydroxytamoxifen (4HT) Z-endoxifen (Z-END) by capillary blood sampling. A prospective, single-centre women with stage 0-3 cancer receiving adjuvant 20 mg/day for a minimum 2 months. Study design: Blood samples repeated measurement TAM, 4HT Z-END were drawn in total at 4-time points, inclusion (baseline), after 1, 2, 3 weeks each participant; venously two time-points, participant. At baseline, test concentrations taken first research nurse second patient. time, participants will be asked leave 1 vial using rhelise™ kit conventional venous plasma. Primary Objective To among patients who have ongoing testing equivalence between found sample (gold standard). endpoint correlations baseline sampling (whole blood/plasma). Secondary objectives user acceptability self-testing comparing patient nurse. endpoints Capillary baseline. was used 40 participants. Mean did not differ significantly types samples. TDM TAM feasible.