Half of all women taking tamoxifen fail to complete the five-year treatment course, according to a retrospective cohort study of all women with incident breast cancer in Tayside, Scotland, carried out between 1993 and 2002. The median duration of use among the 1,633 women in the study who were prescribed the drug was 2.42 years. Adherence below 80 per cent was associated with poorer survival (HR 1.10, 95% CI 1.001-1.21). Only 49 per cent of women taking the drug continued therapy for five years and younger women were more likely to stop early.

McCowan C, Shearer J, Donnan PT et al. Br J Cancer 2008;doi:10.1038/sj.bjc.6604758

Originally published in the November 2008 edition of MIMS Oncology & Palliative Care.