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Evaluating the feasibility of performing window of opportunity trials in breast cancer
Angel Arnaout1, Susan Robertson2, Iryna Kuchuk3
1Division of Surgical Oncology, Department of Surgery, Ottawa Hospital, Ottawa, ON, Canada ; Cancer Therapeutics Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada.
Background:
The waiting period to surgery represents a valuable "window of opportunity" to evaluate novel therapeutic strategies. Interventional studies performed during this period require significant multidisciplinary collaboration to overcome logistical hurdles. We undertook a one-year prospective window of opportunity study to assess feasibility.
Methods:
Eligible newly diagnosed postmenopausal, estrogen receptor positive breast cancer patients awaiting primary surgery received anastrozole daily until surgery. Feasibility was assessed by (a) the proportion of patients who consented and (b) completed the study. Comparison of pre- and poststudy Ki67 labelling index and cleaved caspase 3 scores (CC3) was performed.
Results:
22/131 (16.8%) patients were confirmed eligible and 20/22 (91%) patients completed the study. 19/20 (95%) patients agreed to undergo optional additional tissue biopsies. The mean duration of anastrozole use was 24.7 (15-44) days. There were a statistically significant decline in mean Ki67 indices of 48.8% (p < 0.001) and a trend towards significance in the decline of CC3 (p = 0.17) when comparing pre- with posttreatment values.
Conclusion:
window of opportunity trials in breast cancer are a feasible way of assessing the biologic efficacy of different therapies in the presurgical setting. The majority of eligible women were willing to participate including undergoing additional tissue biopsies.
Insights
Presurgical window of opportunity trials are feasible for evaluating breast cancer therapies. Most eligible patients consented and completed the study, showing a significant decrease in Ki67 proliferation index after anastrozole treatment.
Area of Science:
- Oncology
- Pharmacology
Background:
- The presurgical period offers a unique
- window of opportunity
- to test new treatments for breast cancer.
- Conducting interventional studies during this time requires extensive collaboration and planning.
Purpose of the Study:
- To assess the feasibility of a one-year prospective
- window of opportunity
- study for evaluating therapeutic strategies in breast cancer patients awaiting surgery.
- To determine patient willingness to participate in such trials, including optional biopsies.
Main Methods:
- A prospective study involving newly diagnosed, postmenopausal, estrogen receptor-positive breast cancer patients awaiting primary surgery.
- Patients received daily anastrozole until surgery.
- Feasibility was measured by patient consent and study completion rates. Ki67 labelling index and cleaved caspase 3 (CC3) scores were compared pre- and post-treatment.
Main Results:
- Out of 131 patients, 22 were eligible, and 20 (91%) completed the study.
- Ninety-five percent of participants agreed to optional additional tissue biopsies.
- A statistically significant 48.8% decline in mean Ki67 indices was observed, with a trend towards significance for cleaved caspase 3 (CC3) scores.
Conclusions:
- Window of opportunity trials are a feasible method for assessing the biological effectiveness of therapies in the presurgical breast cancer setting.
- Most eligible women were willing to participate, even with additional biopsies.
