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The Mistletoe and Breast Cancer (MAB) Study: A UK Mixed-Phase, Pilot, Placebo-Controlled, Double-Blind, Randomised Controlled Trial
by
,
Lorna J. Duncan
1
,
Susan Bryant
1,
Gene Feder
1,
Maria Gresham
2,
Poppy Gibson
2,
Debbie Sharp
1,
Jeremy P. Braybrooke
2,3 and
Alyson L. Huntley
1,* 1
Centre for Academic Primary Care, University of Bristol, Bristol BS8 2PS, UK
2
Bristol Medical School, University of Bristol, Bristol BS8 1UD, UK
3
Bristol Haematology and Oncology Centre, University Hospitals Bristol and Weston NHS Foundation Trust, University of Bristol, Bristol BS1 3NU, UK
*
Author to whom correspondence should be addressed.
Cancers 2025, 17(19), 3169; https://doi.org/10.3390/cancers17193169
Submission received: 11 August 2025
/
Revised: 25 September 2025
/
Accepted: 26 September 2025
/
Published: 29 September 2025
(This article belongs to the Special Issue Empowering Cancer Survivors: A Comprehensive Approach to Supportive Care Through Pharmacological and Non-Pharmacological Approaches Including Exercise, Physical Activity and Nutrition)
Simple Summary
The Mistletoe and Breast Cancer (MAB) randomised placebo-controlled, double-blind trial investigates the feasibility of the use of the herbal medicine mistletoe (Viscum album) as an adjunct supportive therapy alongside conventional cancer treatment within the National Health Service in the United Kingdom.
Abstract
Background/Objective: To test the feasibility of a mixed-phase, pilot, placebo-controlled, double-blind trial of mistletoe therapy (MT) with an embedded qualitative study in the UK National Health Service (NHS) setting. Methods: The aim was to recruit 45 patients via an NHS oncology centre with a diagnosis of early or locally advanced breast cancer. Participants were allocated to Iscador® Malus, Iscador® Pinus, or physiological saline (placebo). Diaries and quality-of-life questionnaires were administered. Qualitative interviews were conducted with participants, oncologists, and nurses. Feasibility was assessed by recruitment, retention, adherence, blinding, and safety. Results: Sixty-seven patients were approached between August 2019 and March 2020, 15 gave consent, 14 participants were randomised, and 2 withdrew during the trial. Ten participants and five staff were interviewed. Barriers to recruitment were the additional treatments/time, extra injections, and the possibility of placebo allocation. Adherence was very good whilst the participants were on the study therapy. Diaries and interviews indicated that 11/14 participants struggled with injections and skin reactions. There were 22 adverse events due to the MT, related to the injections or skin reactions. Conclusion: This pilot study examined the feasibility of conducting a randomised placebo-controlled, double-blind trial of mistletoe therapy for breast cancer patients within the UK NHS. The results describe the challenges and achievements of recruitment, retention, adherence, blinding, and safety in this context.
