Two reviews on mistletoe for cancer
Here are two recent reviews on mistletoe for cancer treatment, the first dealing with survival, the second with reduction in side effects of treatment.
The reviews did not support the use of mistletoe for either purpose.
Edzard Ernst commented on the papers:
https://edzardernst.com/2019/02/mistletoe-treatment-for-cancer-is-useless-and-should-be-discouraged/He wrote: "I therefore think that it is time to call it a day. We should stop the funding for further research into this dead-end alley. More importantly, we must stop giving false hope to cancer patients. All that mistletoe therapy truly does is to support a multi-million Euro industry."
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Journal of Cancer Research and Clinical Oncology
March 2019, Volume 145, Issue 3, pp 695–707
Mistletoe in oncological treatment: a systematic review
Part 1: survival and safety
M. Freuding (1), C. Keinki (1), O. Micke (2), J. Buentzel (3), Jutta Huebner (1)
1.Klinik für Innere Medizin II, Hämatologie und Internistische Onkologie, Universitätsklinikum Jena, Jena, Germany
2. Klinik für Strahlentherapie und Radioonkologie, Franziskus Hospital, Bielefeld, Germany
3. Klinik für Hals-Nasen-Ohren-Heilkunde, Südharzklinikum Nordhausen, Nordhausen, Germany
Abstract
Purpose:
Mistletoe treatment of cancer patients is discussed highly controversial in the scientific literature. Aim of this systematic review is to give an extensive overview about current state of research concerning mistletoe therapy of oncologic patients regarding survival, quality of life and safety.
Methods:
In September and October 2017 Medline, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), PsycINFO, CINAHL and “Science Citation Index Expanded” (Web of Science) were systematically searched.
Results:
The search strategy identified 3647 hits and 28 publications with 2639 patients were finally included in this review. Mistletoe was used in bladder cancer, breast cancer, other gynecological cancers (cervical cancer, corpus uteri cancer, and ovarian cancer), colorectal cancer, other gastrointestinal cancer (gastric cancer and pancreatic cancer), glioma, head and neck cancer, lung cancer, melanoma and osteosarcoma. In nearly all studies, mistletoe was added to a conventional therapy. Patient relevant endpoints were overall survival (14 studies, n=1054), progression- or disease-free survival or tumor response (10 studies, n=1091). Most studies did not show any effect of mistletoe on survival. Especially high quality studies do not show any benefit.
Conclusions:
With respect to survival, a thorough review of the literature does not provide any indication to prescribe mistletoe to patients with cancer.
https://link.springer.com/article/10.1007/s00432-018-02837-4Excerpts:
"Background
"Mistletoe (Viscum album) is a small plant which grows as hemiparasites on a wide range of host trees in Europe, Asia and North Africa. Contents of mistletoes are vincetoxins, lectins, polysaccharides, flavonoids, triterpenes and polypeptides (Huebner 2008).
"There are two different groups of mistletoe supplements. On the one hand phytotherapeutic mistletoe extracts are standardized on a certain lectin level (e.g. Cefalektin®, Eurixor®, Lektinol®) and on the other hand there are anthroposophical or homeopathically produced mistletoe supplements (e.g. Abnoba viscum® Helixor®, Iscador®, Iscucin®, Isorel®) (Lange-Lindberg et al. 2006). Two different kinds of positive mechanisms of mistletoe are discussed in literature. First, some authors support the thesis that mistletoe has a direct or indirect anti-tumoral effect either via cytotoxic substances or via lectins which activate the immune system. Second, according to some authors mistletoe shall improve well-being and quality of life and reduce side effects, maybe by endorphin release.
"Mistletoe treatment of cancer patients is discussed highly controversial in the scientific literature. On the one hand, some authors suggested a clear benefit of mistletoe treatment regarding quality of life (Melzer et al. 2009; Kienle and Kiene 2007, 2010; Kienle et al. 2009; Bussing et al. 2012), survival (Ostermann, 2009), toxicity of main intervention (Kienle and Kiene 2007, 2010; Kienle et al. 2009) and possible also tumor remission and survival (Kienle and Kiene 2007; Kienle et al. 2009). On the other hand, Ernst et al. (2003) concluded that mistletoe treatment has no benefit for cancer patients. Further Horneber et al. (2008) und Lange-Lindberg et al. (2006) concluded that results regarding efficacy concerning survival and toxicity reduction were insufficient. However, their results also provide first support that mistletoe seems to improve quality of life in general (Horneber et al. 2008) or at least for breast cancer patients in Germany (Lange-Lindberg et al. 2006). All authors of these systematic reviews and meta-analysis were relatively conform about the great heterogeneity and the more or less insufficient methodological quality of clinical mistletoe research to that date. As even the newest one of these works was published several years ago, a systematic summary also including recent literature regarding mistletoe is lacking."
"Conclusion
"Most studies did not show any effect of mistletoe on survival. Especially high quality studies do not show any benefit. There are some arguments to assume that genuine side effects from mistletoe or interactions with conventional therapy may not be reported adequately in studies and not even noticed in regular cancer care. Accordingly, the benefit-risk-assessment for mistletoe is difficult and no evidence-based indications can be stated today. Physicians should not prescribe mistletoe in case of leukemia, lymphoma or renal cancer and melanoma. Furthermore, interactions with cancer drugs should be avoided and more attention should be paid to reporting possible interaction in scientific publications."
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Journal of Cancer Research and Clinical Oncology
April 2019, Volume 145, Issue 4, pp 927–939
Mistletoe in oncological treatment: a systematic review
Part 2: quality of life and toxicity of cancer treatment
M. Freuding (1), C. Keinki (1), S. Kutschan (1), O. Micke (2), J. Buentzel (3), Jutta Huebner (1)
1. Klinik für Innere Medizin II, Hämatologie und Internistische Onkologie, Universitätsklinikum Jena, Jena, Germany
2.Klinik für Strahlentherapie und RadioonkologieFranziskus Hospital, Bielefeld, Germany
3.Klinik für Hals-Nasen-Ohren-Heilkunde, Südharzklinikum Nordhausen, Nordhausen, Germany
Abstract
Purpose:
One important goal of any cancer therapy is to improve or maintain quality of life. In this context, mistletoe treatment is discussed to be highly controversial. The aim of this systematic review is to give an extensive overview about the current state of evidence concerning mistletoe therapy of oncologic patients regarding quality of life and side effects of cancer treatments.
Methods:
In September and October 2017, Medline, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), PsycINFO, CINAHL and “Science Citation Index Expanded” (Web of Science) were systematically searched.
Results:
The search strategy identified 3647 articles and 28 publications with 2639 patients were finally included in this review. Mistletoe was used in bladder cancer, breast cancer, other gynecological cancers (cervical cancer, corpus uteri cancer, and ovarian cancer), colorectal cancer, other gastrointestinal cancer (gastric cancer and pancreatic cancer), glioma, head and neck cancer, lung cancer, melanoma and osteosarcoma. In nearly all studies, mistletoe was added to a conventional therapy. Regarding quality of life, 17 publications reported results. Studies with better methodological quality show less or no effects on quality of life.
Conclusions:
With respect to quality of life or reduction of treatment-associated side effects, a thorough review of the literature does not provide any indication to prescribe mistletoe to patients with cancer.
https://link.springer.com/article/10.1007%2Fs00432-018-02838-3Excerpts:
"One of the most common methods is therapy with mistletoe (Viscum album). Mistletoe treatment of cancer patients was already examined in several systematic reviews and is discussed to be controversial in science. Some authors suggest a clear benefit of mistletoe treatment regarding quality of life (Melzer et al. 2009; Kienle and kiene 2007, 2010; Kienle et al. 2009; Bussing et al. 2012), other authors concluded that mistletoe treatment has no benefit for cancer patients (Ernst et al. 2003) or that results regarding efficacy concerning survival and toxicity reduction were insufficient (Horneber et al. 2008; Lange-Lindberg et al. 2006). However, their results provide the first support that mistletoe could improve quality of life (Horneber et al. 2008). Yet, all authors of systematic reviews and meta-analysis were relatively aware about the great heterogeneity and the more or less insufficient methodological quality of clinical mistletoe research to that date. As even the newest one of these reviews was published several years ago, a systematic summary also including recent literature regarding mistletoe is lacking."
"Quality of life was examined in most of the included studies. As in previous reviews (Bussing et al. 2012; Horneber et al. 2008; Kienle et al. 2009; Kienle and Kiene 2007, 2010; Lange-Lindberg et al. 2006; Melzer et al. 2009), in majority of these studies, positive effects of mistletoe treatment on quality of life were found (Grossarth-Maticek and Ziegler 2006a, 2007a, b, c, 2008; Heiny and Albrecht 1997; Lenartz et al. 1996; Longhi et al. 2009; Piao et al. 2004; Semiglasov et al. 2004; Semiglazov et al. 2006; Troger et al. 2012, 2014a, 2016)."
"Nevertheless, there are several reasons why these data are insufficient to confirm the statement that mistletoe treatment improves quality of life in cancer patients.
"First of all, as quality of life is a subjective endpoint in all studies there was a high risk for performance and detection bias because of missing blinding. Neither a placebo effect nor an effect due to an increased attention on complaints in the treatment group can be excluded as an explanation in any of the positive studies. Additionally, there is a high risk of attrition bias in many studies because of higher dropout rates."
"Conclusion
"To date, no clear statement regarding the efficacy of mistletoe treatment can be derived from randomized controlled studies. Studies with better methodology show less or no effects on quality of life or side effects of cancer therapy. There are some arguments to assume that genuine side effects from mistletoe or interactions with conventional therapy may not be reported adequately in studies and not even noticed in regular cancer care. Accordingly, the benefit–risk assessment for mistletoe is difficult and no evidence-based indications can be stated today. Physicians should not prescribe mistletoe in case of leukemia, lymphoma or renal cancer and melanoma. Furthermore, interactions with cancer drugs should be avoided and more attention should be paid to reporting any possible interaction in scientific publications."
