Adjuvant bisphosphonate use in patients with early stage breast cancer: a physician survey

Despite the increasing use of adjuvant bone-modifying agents (BMAs) such as zoledronate and clodronate in the treatment of patients with early stage breast cancer (EBC), little is known about real world practice patterns. A physician survey was performed to address this deficit and determine interest in clinical trials of alternative strategies for BMA administration.

Canadian oncologists treating patients with EBC were surveyed via an anonymized online survey. The survey collected information on: physician demographics, knowledge and interpretation of adjuvant bisphosphonate guidelines, and real world prescribing practices. Questions also determined thoughts around the design of future adjuvant BMA trials.

Of 127 surveyed physicians, 53 eligible invitees responded (response rate 42%). The majority of physicians are offering high-risk postmenopausal patients adjuvant BMAs. The most common BMA regimen was adjuvant zoledronate (45/53, 85%) every 6 months for 3 years. Concerns around toxicities and repeated visits to the cancer centre were perceived as the greatest barriers to adjuvant bisphosphonate use. Respondents were interested in future trials of de-escalation of BMAs comparing a single infusion of zoledronate vs. 6-monthly zoledronate for 3 years. The most favoured primary endpoints for such a trial included disease recurrence and fragility fracture rates.

Questions around optimal use of adjuvant bisphosphonates in patients with EBC still exist. There is interest among physicians in performing trials of de-escalation of these agents. The results of this survey will assist in designing pragmatic clinical trials to address this question.