Mistletoe and Cancer
“Mistletoe” has been used for decades in Europe as an adjunct to conventional cancer care. The statistic stated is that 75% of people in Europe receiving treatment for cancer are also receiving Mistletoe. So what exactly is Mistletoe, what is its mode of action and does it actually work?
What is Mistletoe?
Mistletoe is formally known as Viscum album and is a composition of purely aqueous fresh plant extracts from the white-berry mistletoe. It is used in the cancer setting as an adjuvant therapy to conventional treatment with the aim of minimising the risk of cancer progression or recurrence as well as in the palliative setting for cancer to improve quality of life. It is also used for prevention in precancerous conditions or where risk factors exist.
How Does it Work?
Mistletoe has a number of ingredients that act by inducing the body’s own immune system to act against the cancer cells themselves.
Glycoproteins cause macrophage activation, release of TNF-α, IL-1, IL-2, IL-8 and eosinophilia and cause cytotoxicity through inhibition of ribosomal protein synthesis and induction of apoptosis (intrinsic pathway). Polypeptides cause macrophage activation, increased phagocytosis activity of granulocytes and cytotoxicity through cell membrane leakage. Oligo and polysaccharides cause indirect, immune-mediated tumor inhibition and stimulation of T-helper cells (TH1 ↑, IFN-y ↑) and increased NK cell activity. Flavonoids are antioxidant, anti-inflammatory and antinociceptive and cause induction of apoptosis. Phenylpropane glycosides are antioxidant and allow for stress protection and immunoprotection. Triterpenes cause induction of apoptosis and cell differentiation. They are also antiangiogenic, anti-inflammatory with antioxidant effects and immunoprotection.
What are the types of Mistletoe?
There are three main types of Mistletoe with increasing levels of Mistletoe lectins and therefore increasing in strength. Abeitis is made from Fir Mistletoe and is best used in head and neck cancer, lung cancer, prostate cancer and leukemia. Mali is made from apple tree Mistletoe and is best used in breast (high BMI, postmenopausal), bladder, gynaecological and gastrointestinal malignancy. Pini is made from Pine Mistletoe and is best used in breast (low BMI, premenopausal), sarcoma, skin, kidney, testicular, CLL, lymphomas, and carcinomas with multiple or diffuse metastases.
It is administered as a subcutaneous injection typically 2-3 times per week and is also available as an intravenous infusion and in certain circumstances as intratumoural injections.
What are the effects?
A local inflammatory reaction at the injection site is typical and ideal. Low grade temperature and improved internal warming is also reported. An increase in leucocytes is often evident as is an acute peritumoural inflammatory reaction (ie swelling around the tumour). It is thought to restore physiological rhythms including the circadian cycle.
Typical effects include; immunomodulation which leads to reduced susceptibility to infections and indirect immune-mediated tumor inhibition. Immunoprotection (DNA stabilisation) which leads to better tolerability of chemotherapy and less immunosuppression by chemotherapy. Neuroendocrine effects which lead to improved quality of life (especially fatigue). Tumor inhibition (apoptosis ↑, angiogenesis ↓) leading to prolongation of survival time and tumour regression in specific cases.
What are the Therapeutic Indications and Clinical Benefits?
Mistletoe is used for malignant tumors, also with concomitant disorders of the hematopoietic system, for relapse prevention following tumor surgery, for defined precancerous conditions (eg CIN, hepatitis, intestinal polyps, colitis ulcerosa) and for some benign tumors (eg uterine myomas, endometriosis, brain tumors).
These can begin as early as within a few weeks of commencing treatment but can take several months before a response is clinically felt or detected. The longer the time spent on therapy the better the response to therapy (2 years to 5 years is ideal at the discretion of the treating physician). Beginning treatment as early as possible has proven to be beneficial.
An improvement of general condition and quality of life is often seen with increasing performance and zest for life, reduction of cancer-related fatigue, normalisation of body rhythms (temperature, sleep, digestion), increased appetite, improvement of nausea/vomiting, emotional well-being, improvement of depression and anxiety and decrease in tumor-related pain.
Laboratory Parameters often show a leukocytosis initially and then a dose dependent increase in eosinophils from week 3 and after 1-3 months of use, an increase in absolute lymphocyte count.
Subcutaneous therapy does not lead to tumor regression. However, it can lead to retardation or stagnation of tumor progression. If mistletoe therapy should lead to tumor regression, this usually takes a longer period of approximately 6 months compared with chemotherapy. Therefore, as a rule, a combination with oncological treatment is necessary to achieve a rapid tumor response.
What are the Contraindications and Adverse Reactions?
It is contraindicated for use in the setting where there is an allergy to mistletoe preparations, acute inflammation or highly febrile diseases, florid autoimmune diseases and those under immunosuppressive therapy and in the setting of hyperthyroidism with tachycardia. In tumors that are in contained anatomical spaces eg spinal cord, brain, liver, intact prostate, caution should be exercised due to peri-tumoural swelling and risk of oedematous swelling and pressure.
Adverse reactions include local inflammatory reactions at the injection site, fever and flu-like symptoms and allergic reactions. The rare adverse reactions include regional swelling of lymph nodes, activation of pre-existing inflammation, chronic granulomatous inflammation and autoimmune disease and increased intracranial pressure in brain tumors or metastases.
Conclusion
This provides an overview of the use of mistletoe. Please refer to Part 2 describing the clinical evidence due for release shortly. As with all the information provided, please consult a practitioner experienced in the administration and prescription of Mistletoe if interested in exploring its use.
References
Compendium of Mistletoe Therapy with Helixor in Integrative Oncology
