Compliance with Tamoxifen and Arimidex in the adjuvant treatment of women with breast cancer

Objectives: The level of compliance for pharmacological therapies in chronic diseases varies, but is predominantly low. With Tamoxifen (TAM), 23% and 50% of non compliance after 1 and 4 years have been reported. No data on Anastrozol has yet been reported. The aim of this study was to evaluate the compliance rate in women with breast cancer on treatment with TAM or ANA.

Materials and methods: We investigated a random sample of 100 postmenopausal women with breast cancer (50 TAM and 50 ANA) who have been operated in our hospital in 2004/2005 and thereafter have been assigned to an adjuvant endocrine treatment. We have evaluated the compliance rate via self-report and additionally performed a prescription control of the hospital chart and by recall of the local physicians.

Results: Baseline characteristics comprised a significant different mean age of 65 (+ 3) and 72 (+ 3) in women on ANA vs. TAM (p<0.02). The median duration of treatment was 13.6 (+8.8) for TAM and 16.6 (+5.4) for ANA. All women on TAM and ANA were compliant by self report. After the controlling for prescriptions, only 40 (80%) and 29 (66%) of the women on TAM and ANA were still classified compliant (MPR>80%). Conclusions: Our results support the suboptimal compliance of women with breast cancer on adjuvant TAM treatment. Additionally, we for the first time evaluated an equivalent low compliance with ANA. More prospective studies are needed to increase our understanding of the underling reasons for non compliance in women with breast cancer.