Physician Survey of Timing of Adjuvant Endocrine Therapy Relative to Radiotherapy in Early Stage Breast Cancer Patients.

Background: Patients can start endocrine therapy before, concurrently with, or sequentially after radiotherapy. The optimal timing of starting adjuvant endocrine therapy is unknown. This survey was performed to evaluate physician recommendations.

Methods: Canadian oncologists were surveyed to evaluate institutional and personal practices regarding the prescription of adjuvant endocrine therapy and radiotherapy. Perspectives regarding the design of a clinical trial to compare concurrent versus sequential therapy, and the optimum end points for such a trial, were also sought.

Results: The overall response rate was 30% (65/220), with responses mainly from medical (35/65, 54%) and radiation (28/65, 43%) oncologists. Eighty-four percent of respondents reported an absence of institutional protocols. The majority of physicians (57%, 36/65) identified endocrine therapy provided after radiotherapy as the preferred sequence of treatments. Twenty-two percent (14/65) had no preference, while 21%, (14/65) started endocrine therapy either before or concurrent with radiotherapy. Practice patterns were largely based on the physician's own clinical experience. Thirty-two percent of physicians (21/65) had concerns regarding concurrent endocrine therapy and radiotherapy, including increased adverse effects with endocrine therapy (13/21, 62%), reduced efficacy of radiotherapy (4/21, 19%), reduced compliance with endocrine therapy (3/21, 14%), and increased radiation toxicity (1/21, 5%). Most thought a pragmatic clinical trial addressing this question would help standardize and improve patient care.

Conclusion: Decisions around the timing of endocrine therapy and radiotherapy are largely being made on the basis of physicians' personal choices. In the absence of data to support these decisions, appropriately powered trials are needed.