Doctors' participation in randomized trials of adjuvant systemic therapy in breast cancer: how does it relate to their recommendations for standard therapy in breast cancer?

A cross-sectional survey of all medical and radiation oncologists in Austra lia was undertaken, plus surgeons listed as participants of the ANZ Breast Cancer Trials Group, to examine whether doctors' participation in randomize d trials of adjuvant systemic therapy for breast cancer, is associated with their recommendations for adjuvant therapy in two clinical scenarios. Two- hundred and sixty-nine questionnaires were returned (response rate 71%). Fi fty-six per cent of respondents, were participating in current adjuvant sys temic therapy trials. Radiation oncologists were significantly more likely than surgeons or medical oncologists to recommend radiotherapy, while medic al oncologists and surgeons were significantly more likely than radiation o ncologists to recommend chemotherapy, in both clinical scenarios. In a mult ivariate analysis adjusting for the differences between specialist groups, respondents recommending chemotherapy were more likely to be high accruers to clinical trials (OR 3.6, 95%CI 0.93 to 13.9, P=0.08) in scenario 1, or p articipants of a breast cancer trials organization (OR 3.1, 95%CI 1.6 to 5. 9, P=0.001) in scenario 2. Some of the variation in adjuvant systemic thera py recommendations is associated with participation in adjuvant systemic th erapy trials. However, this study is unable to determine if trial participa tion influences opinions about adjuvant therapy, or opinions influence tria l participation. (C) 1999 Harcourt Publishers Ltd.