What complementary cancer therapies are actually supported by evidence?
Key Takeaways
Sometimes patients aren’t aware of the key distinction between complementary cancer therapies and alternative therapies.
Complementary therapies—those which accompany the standard of care—can include mind-body practices as well as nutritional interventions that purport to alleviate adverse effects of cancer care.
Evidence suggests some efficacy for interventions such as fasting, biofeedback, yoga, and massage therapy, but in many cases, it’s too early to draw broad conclusions.
For many patients, a cancer diagnosis marks the onset of two battles: There’s the fight against the disease, and then there’s the fight against the adverse effects of treatment. From chemo-related nausea and fatigue, to anxiety and depression, these effects prompt patients and healthcare professionals alike to turn to an array of interventions and complementary therapies to help people with cancer.
But what does the literature say about some of these complementary therapies? Have some been proven to be more efficacious than others? And what can cancer patients reasonably expect to gain from them?
Complementary medicine vs alternative medicine
Patients who are struggling with a cancer diagnosis or cancer treatment often turn to complementary medicine and alternative medicine for relief, and hope. But sometimes they do not understand the critical distinction between these two approaches.
Complementary medicine includes mind-body practices such as mediation, yoga, biofeedback, or hypnosis.[] It can also incorporate biologically based practices, such as vitamins and supplements; body-based practices, such as chiropractice or massage; and energy-based practices, such as reiki.
The key distinction between complementary medicine and alternative medicine is that in complementary medicine, these therapies and practices are used in conjunction with the standard of care. For example, a patient might use acupuncture to reduce the adverse effects of chemotherapy.
Alternative medicine may use these practices, or others such as diet, in lieu of the standard of care for cancer. In many instances, there is little or no research to support alternative medicine.
With this critical distinction in mind, what does the research have to say about some of the more common complementary medicine practices used by oncology patients?
Fasting
Fasting has received a lot of attention in health and wellness circles for purported weight loss and cell autophagy implications. But does it have a place in oncology? The research seems to indicate that it’s too early to tell, but there are some interesting findings.
For example, a 2020 Nature Communications study compared a fasting mimicking diet (FMD) with a regular diet in a group of 131 patients with HER2-negative stage II and III breast cancer who were receiving chemotherapy.[] While toxicity was comparable in both groups, radiologically partial or complete response occurred more often in the FMD group.
Moreover, the Miller & Payne 4 / 5 pathological response, signifying 90%-100% tumor-cell loss, was more common in the FMD group. FMD also appeared to curtail chemotherapy-induced DNA damage to T-lymphocytes.
“The results suggest that an FMD significantly reinforces the effects of neoadjuvant chemotherapy on the radiological and pathological tumor response in patients with HER2 negative early breast cancer,” the researchers wrote. They advocate for further investigation.
Biofeedback
Biofeedback is a type of therapy that combines electronic monitoring of certain bodily functions, such as heart rate and heart rate variability, with conscious efforts to control those functions. The Mayo Clinic explains that patients might use biofeedback to relax muscle groups or slow their respiration rate, for example, with the objective of reducing pain or stress.[]
Biofeedback in oncology is another area where evidence is interesting, but early.
A 2019 review article assessed the effects of neurofeedback (a type of biofeedback using brain waves) in patients with cancer.[] Specifically, the researchers were curious about how neurofeedback affects symptoms and the care burden in patients and cancer survivors. Because only a few studies met the inclusion criteria for the review—three experimental studies, one observational study, and two case reports—conclusions are somewhat limited.
Regardless, researchers said that there is some evidence that this drug-free, non-invasive therapy may ameliorate pain, fatigue, and depression, as well as help with sleep, in this patient population.
“In other areas [such] as neurology, psychology, and psychiatry, there is much evidence that [electroencephalogram biofeedback or neurofeedback] has the potential to ameliorate these symptoms,” the researchers wrote.
Yoga
Yoga is another practice that receives a great deal of attention for its purported health benefits. But does it have a role to play in cancer care? A 2019 review article published in Cancer suggests that it does.[]
The review article included 29 randomized, controlled trials that assessed whether yoga affected quality of life, including subdomains such as fatigue, pain, stress, sleep, anxiety, depression, and cognitive function. Researchers found that before and after cancer treatment, yoga improved quality of life, specifically in the form of fatigue reduction. Findings also indicated that yoga alleviated stress, and improved sleep and cognition. Several trials included in the review even indicated that yoga improved biomarkers of immune function, stress, and inflammation.
"It is noteworthy that none of the trials documented any serious adverse events associated with yoga, and only some minor adverse events were reported (eg, muscle soreness)."
— Cancer
Evidence was less conclusive for yoga’s ability to moderate anxiety, depression, pain, and some cancer-specific symptoms.
Massage therapy
Sleep disturbance is an unfortunately common adverse effect of cancer therapy. While pharmacology may be an option for these patients, these drugs have adverse events of their own. Can massage promote relaxation that leads to better sleep?
A systematic review of randomized, controlled trials suggests that it can.[]
In fact, massage therapy may be more effective than relaxation therapy for improving sleep in patients dealing with cancer.
The review included four randomized, controlled trials on massage therapy for patients with cancer, and three on relaxation therapy. Patients who received massage therapy demonstrated statistically significant improvement in sleep, as evidenced by answers on a self-reported sleep questionnaire and on empirical measurement of sleep duration.
Those who received relaxation therapy did not experience significant improvements in sleep, although there was evidence of improvements in self-reported sleep quality.
“Such improvements in sleep outcomes for cancer survivors might be of major clinical benefit, as the duration of massage therapy provided was comparatively shorter when compared to the other non-pharmacological interventions like exercise and [cognitive behavioral therapy],” the researchers wrote.
Other options
Clinical evidence supports far more than these complementary cancer therapies. For example, tai chi,[] meditation,[] hypnosis,[] and acupuncture[] all appear at least somewhat efficacious for symptom and/or adverse effect relief.
The key may be aligning complementary therapies that are supported by evidence with patient needs and desires. For example, biofeedback may be a sound option for a patient, but if they don’t want to do it, then pushing the intervention may be a clinical dead end.
Regardless, the assessment of potential, evidence-based complementary therapies presents another opportunity to engage in clinician-patient dialogues that yield shared understanding, as well as aligned treatment goals. That may position patients for better cancer care and fewer adverse effects.
What this means for you
The internet and social media are replete with information on complementary and alternative cancer therapies. This information ranges from good to dangerous. Knowledge of the clinical evidence for complementary cancer therapies can better direct patients to interventions that first do no harm and second actually work.