Cancer Patients' Experiences of Using Mistletoe (Viscum album): A Qualitative Systematic Review and Synthesis

Systematic reviews of mistletoe therapy (MT) trials in cancer show promising results in improvement of patients' quality of life during chemotherapy and reduction of fatigue. However, patients' experiences of side effects and the acceptability, tolerability, and perceived benefits of MT have not been systematically reviewed. The aim of this study was to systematically review and synthesise the results of qualitative studies of cancer patients' experiences of using MT.

A systematic search was conducted in MEDLINE, Embase, PsychLIT, CINAHL, and AMED to identify qualitative studies of MT. Articles were screened independently by two reviewers and critically appraised using the Critical Appraisal Skills Programme tool. A thematic synthesis of the findings was carried out.

One hundred and seventy-three papers were identified; 156 were excluded at initial screening. Seventeen papers were read in full, 14 of which were excluded. Three articles about patients' experiences of MT alongside conventional treatment were included in the synthesis, either as a monotherapy (two articles) or as part of a package of anthroposophic treatment (one article). Patients reported demonstrable changes to their physical, emotional, and psychosocial well-being following MT, as well as a reduction in chemotherapy side effects. Self-reported side effects from MT were few, and the studies suggest good adherence to the therapy. Self-injection gave patients a sense of empowerment through involvement in their own treatment.

A systematic search revealed a small number of qualitative studies of MT in cancer. These were effectively combined to provide a detailed overview of patients' experiences in order to complement the developing evidence base from trials. Given the variation in context of MT delivery across the articles, it is not possible to ascribe changes in patients' quality of life specifically to MT. The results of this review will help in the design of outcome measures that more fully capture patients' experiences. It is essential to embed qualitative research of patients' experiences of MT and other CAM therapies within future trials.