Abstract 75P
Background
Ki-67 response to pre-operative endocrine therapy (ET) in early breast cancer is both prognostic and an evidence-based tool to guide adjuvant treatment decisions. While this approach is utilized in many countries, current usage in Canada is unclear. Physicians across Canada were surveyed to explore current practice patterns, perceptions, and perceived barriers to use of Ki-67 in management of early-stage breast cancer.
Methods
Physicians were invited by email to participate in an anonymous survey using Microsoft Forms and were eligible if they prescribe systemic therapy for breast cancer in Canada. Respondents were asked to describe their usage of Ki-67, perceptions of the evidence surrounding Ki-67 ET response, and interest in future trials using this approach. Responses are summarized descriptively.
Results
The survey received 48/163 responses (29.4%), 6 of whom were ineligible. Majority of respondents (97.6%) reported having access to Ki-67 testing upon request. Guiding decisions on adjuvant Abemaciclib was the most common use (97.6%), followed by adjuvant chemotherapy decisions (16.7%), and prognostication (9.52%). Only 19.0% had used Ki-67 response to pre-operative ET in practice, however 69.0% reported they would use it if more easily available. Common barriers identified to this approach included lack of awareness by other providers (54.8%), increased resource requirement (54.8%), lack of timely Medical Oncology consultation prior to surgery (52.4%), potential surgical delays (38.1%), and modest or unclear benefit (19.0%). The majority of physicians (85.3%) reported that they would participate in future trials using Ki-67 endocrine response, and that the number of patients where treatment decisions were changed (95.2%) and cost analysis (42.3%) were important endpoints to include.
Conclusions
Despite widespread availability of Ki-67 testing, few physicians in Canada currently use it to assess endocrine response, predominantly due to logistical and resource constraints. There is a high level of interest in participating in future trials using this strategy, which should focus on both disease related outcomes, feasibility, and the financial impact on the public healthcare system.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.