Tired of tumours hogging the spotlight? Short answer: Red light therapy might not shrink tumours directly—but it could support other treatments and ease side effects. Curious how? This article breaks down the science, the hype, and what Red Light Therapy at Home, Red Light Therapy Panels, and Red Light Therapy Beds can (and can’t) do.
Introduction to Red Light Therapy and Cancer
What is Red Light Therapy (RLT) / Photobiomodulation (PBM)?
Red Light Therapy (RLT), also known as Photobiomodulation (PBM), is a non-invasive treatment that uses specific wavelengths of light to stimulate cellular function. It's commonly applied using red and near-infrared light to support healing and reduce inflammation.
How RLT Works (cellular level, mitochondria, ATP)
At the cellular level, red and near-infrared light penetrate the skin and are absorbed by mitochondria. This boosts the production of adenosine triphosphate (ATP), the energy currency of cells.
The increased energy can help cells repair and regenerate more effectively. It's this cellular boost that underpins many of RLT’s benefits.
Different wavelengths (red vs. near-infrared)
Red light typically ranges from 620 to 750 nanometres (nm), and near-infrared light from 750 to 1,100 nm. Red light is absorbed more superficially, ideal for skin treatments.
Near-infrared penetrates deeper into tissues, which may be more relevant for targeting internal tumours or inflammation.
The Growing Interest in RLT for Health Conditions
Common uses (skin health, pain relief, wound healing)
RLT is widely used for skin rejuvenation, acne, wound healing, and pain relief. Athletes use it for muscle recovery, and some turn to it for arthritis and joint discomfort.
These widespread applications have increased its popularity and availability.
Why the focus on cancer?
Cancer is one of the most studied diseases globally, and many seek less invasive, complementary treatments. Since RLT is known to affect cellular health and inflammation, researchers are exploring its role in oncology—especially in relation to tumour growth and cancer treatment side effects.
Red Light Therapy and Tumour Growth: Current Evidence
Distinguishing Red Light Therapy from Photodynamic Therapy (PDT)
What is Photodynamic Therapy (PDT)? (involves photosensitising drugs)
PDT involves the use of light-sensitive drugs (photosensitisers) that are activated by specific wavelengths of light. Once activated, these drugs produce a form of oxygen that kills nearby cancer cells.
It's an approved treatment for certain skin, lung, and oesophageal cancers.
RLT as a standalone vs. adjunctive therapy (e.g. enhancing PDT)
Unlike PDT, RLT doesn’t require photosensitisers. It works by stimulating natural biological processes. However, some studies are investigating its use alongside PDT to improve outcomes and reduce side effects.
This combination may enhance tumour cell death while protecting healthy tissue.
Does Red Light Therapy Directly Shrink Tumours?
Overview of preliminary findings and limitations (limited direct evidence for RLT alone)
Research into whether RLT alone can shrink tumours is in the early stages. Some laboratory and animal studies suggest a potential anti-tumour effect, but human data is sparse.
Results are promising but inconclusive, and more high-quality trials are needed before drawing firm conclusions.
Research on specific cancer types (e.g. skin cancers, melanoma in preclinical models, lung cancer in PDT)
Animal studies have shown tumour suppression in models of skin cancer and melanoma. In some PDT trials, red or near-infrared light was used to treat lung tumours with measurable shrinkage.
However, these outcomes are often tied to the combined effect of light and drugs, not RLT alone.
Potential Mechanisms of Action in Oncology
Enhancing cellular function and repair
RLT may support healthy tissue during and after cancer treatments. By increasing ATP, it encourages better cell recovery, which can help repair damage from chemotherapy or radiation.
Anti-inflammatory effects
Chronic inflammation plays a role in cancer progression. RLT has been shown to reduce inflammation markers, which might help suppress tumour-friendly environments.
Impact on tumour microenvironment
Red light might help modulate the tumour microenvironment, making it less supportive of cancer growth. This includes reducing oxidative stress and supporting immune activity.
Synergistic effects with traditional treatments (e.g. chemotherapy, radiation)
Some evidence suggests RLT could make cancer cells more vulnerable to radiation or chemotherapy. It may also reduce side effects like oral mucositis in head and neck cancer patients.
Safety, Considerations, and Recommendations
Is Red Light Therapy Safe for Cancer Patients?
Addressing concerns about stimulating tumour growth (current research suggests it does not stimulate growth and may even inhibit certain types)
There’s been concern that RLT could stimulate tumour growth by boosting cell activity. However, current research does not support this for cancer cells.
In fact, some studies suggest RLT might inhibit or slow the growth of certain tumours.
General safety profile (non-invasive, non-toxic)
RLT is generally considered safe. It’s non-invasive, non-thermal, and doesn’t introduce toxins into the body. This makes it appealing as a supportive option.
Potential Side Effects and Risks (especially in PDT context)
Photosensitivity
Photosensitisers used in PDT can make skin or eyes sensitive to light. This is not an issue with standard RLT, but worth noting if therapies are combined.
Localised reactions (burning, swelling, scarring)
With incorrect usage or overly long exposure, users may experience temporary redness, swelling, or minor burns. Always follow manufacturer guidance.
Important Considerations Before Use
Importance of medical consultation (oncologist guidance)
Before starting RLT, consult a healthcare provider—especially if undergoing cancer treatment. RLT should not interfere with or replace prescribed medical therapies.
RLT as a complementary approach, not a standalone cure
RLT is not a cure for cancer. It may help with symptom relief or treatment support, but it should only be used alongside traditional care.
Variability in effectiveness (wavelength, duration, individual factors)
Results vary depending on the type of light used, treatment duration, and individual health. Clinical-grade equipment offers more consistent outcomes than generic consumer devices.
The Need for More Research and Clinical Trials
Current state of evidence (promising but largely preliminary)
The current body of evidence is mostly preclinical or based on small trials. While the science looks hopeful, it’s too early to make solid claims.
Importance of large-scale randomised controlled trials
To confirm effectiveness and safety, large-scale human trials are necessary. These will help define when and how RLT should be used in cancer care.
Conclusion: Navigating Red Light Therapy in Cancer Care
Summary of Key Takeaways
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Red Light Therapy (RLT) may support cancer care, but evidence is still preliminary.
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It shows promise for reducing inflammation and helping with recovery from treatments.
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Current research does not support fears of tumour stimulation.
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RLT is not a replacement for conventional cancer therapy.
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Always seek medical advice before using RLT if you have or had cancer.
