Eligibility, compliance and persistence of extended adjuvant endocrine therapy for breast cancer

Background. Extended therapy (ET) beyond the standard five years of tamoxifen-containing treatment is a widely discussed therapy option in adjuvant endocrine breast cancer (BC) therapy which might offer an opportunity for further protection against late relapses. In this study we evaluated eligibility, compliance and persistence of extended adjuvant endocrine BC therapy. Patients and methods. Data concerning all BC patients (<= 75 years) who initiated endocrine adjuvant therapy between 1999 and 2005 (n = 286) was analyzed. Results. One hundred and thirty-eight patients were valid candidates for an ET according current guidelines; this represents 48.3% of the individuals who started endocrine therapy five years ago. Of these, 89 (64.5%) received a corresponding offer/recommendation by their treating physicians. Advanced age (p = 0.002), favorable disease stage (p = 0.011), and follow-up at a general practitioner (p < 0.001) were significant factors where a recommendation for an ET was not made. Of the 89 patients who were offered an ET, 64 followed this proposal (compliance: 84.7%). Eighteen patients (28.1%) were non-persistent to the ET; therapy-related adverse effects were the main reason for discontinuation. Sixteen patients received an ET beyond current guidelines (tamoxifen or an aromatase inhibitor alone was given longer than five years); this represents 11.0% of all patients who completed five years of endocrine therapy. Conclusions. Only a minority of the patients who started an endocrine therapy were actually eligible for an ET. Patients who were offered/recommended an ET had a high rate of compliance and persistence. Efforts should be made to make sure that all physicians, above all general practitioners, who are involved in the treatment of BC patients, are provided with current therapy guidelines as to guarantee an optimal patient management.