“Can I laser a patient with cancer?”

Dr. Phil’s Answer:

I always answer cancer question by first pointing out the need to protect your liability. If the patient's cancer returns or worsens, what is the worst that could happen? I am not aware of any lawsuits involving class 4 laser therapy and cancer, but I do think it is something to be aware of. From a scientific/physiological perspective, yes, cancer cells do grow and divide more rapidly in Petri dishes when exposed to laser, but in vivo it appears that laser therapy can have some anti-cancer, anti-tumor effects.

“Protect your liability first. Avoid malpractice. Communicate with the Patient and their family/loved ones. Share the PBM and Cancer papers.”

There is a 2016 paper titled, ‘Laser Therapy Inhibits Tumor Growth in Mice by Promoting Immune Surveillance and Vessel Normalization’ that concluded, “While laser light increased cell metabolism in cultured cells, the in vivo outcome was reduced tumor progression. This striking, unexpected result was paralleled by the recruitment of immune cells, in particular T lymphocytes and dendritic cells, which secreted type I interferons. Laser light also reduced the number of highly angiogenic macrophages within the tumor mass and promoted vessel normalization, an emerging strategy to control tumor progression. Collectively, these results set photobiomodulation as a safety procedure in oncological patients and open the way to its innovative use for cancer therapy.”

PBM expert Michael Hamblin has a 2018 paper titled, ‘Photobiomodulation and Cancer: What Is the Truth?’ in which he writes, “Although there are a few articles suggesting that PBM therapy can be detrimental in animal models of tumors, there are also many articles that suggest the opposite and that light can directly damage the tumor, can potentiate other cancer therapies, and can stimulate the host immune system. Moreover, there are two clinical trials showing increased survival in cancer patients who received PBM therapy. Conclusions: PBM therapy may have benefits in cancer patients and should be further investigated.”

In a 2017 study titled, ‘The effect of photobiomodulation on chemotherapy-induced peripheral neuropathy: A randomized, sham-controlled clinical trial’, patients suffering from chemotherapy induced peripheral neuropathy (CIPN) were treated with a class 4 therapy laser. There was a greater than 90% success rate, and there were no adverse reactions to treatment.

Can you laser a patient who has active cancer? What if they are in remission? For what duration of remission are they ‘safe’? What if it is a blood cancer, such as leukemia, lymphoma, and myeloma? What if they have moles, and a family history of skin cancer? I cannot answer these questions for you. You will need to weigh the pros and cons and decide for yourself whether you choose to treat.

Here is a representative question that I get: “I have a patient that had Throat Cancer but is having shoulder pain. Cancer is in remission. I wanted to see if I can do laser over the shoulder and not be a problem with the cancer.”

In the light of current evidence, I would nudge you towards yes, you should be treating cancer patients in remission suffering from symptoms, whether associated with their cancer treatments, or otherwise.

However, if the patient, their spouse, family, etc expresses any concerns about the cancer patient receiving laser therapy, err on the side of caution and do not treat.

More info on this topic:

Can a Patient With Active Cancer, or a History of Cancer, Receive Class 4 Laser Therapy Treatments?

The question of whether a patient with active cancer, or a history of cancer, can safely receive photobiomodulation (PBM) treatments using a Class 4 therapy laser is both common and appropriate. It reflects a healthy level of clinical caution, as cancer care demands heightened awareness of safety, contraindications, and evidence-based decision making. The short answer is: yes, PBM may be used in many cancer-related scenarios—but with clear boundaries, informed consent, and thoughtful clinical judgment.

Historically, cancer was broadly listed as a contraindication for laser therapy. This conservative stance arose from theoretical concerns that increasing cellular energy production, circulation, or growth-factor signaling might unintentionally stimulate malignant cell activity. However, modern research and clinical experience have substantially refined this understanding. PBM does not act as a nonspecific growth stimulant. Rather, it modulates cellular signaling, reduces inflammation, improves mitochondrial efficiency, and supports tissue repair within the parameters of normal physiological regulation.

For patients with a history of cancer, PBM is generally considered safe when treatments are delivered away from the original tumor site and when there is no evidence of active disease. Many cancer survivors experience chronic pain, neuropathy, joint stiffness, surgical scar adhesions, or radiation-related soft tissue injury. In these cases, Class 4 laser therapy can be an effective tool to manage pain, reduce inflammation, and improve quality of life. The key clinical principle is anatomical discretion—avoiding direct laser application over former tumor sites unless explicitly cleared by the patient’s oncology team.

For patients with active cancer, PBM may still play a role, but with tighter controls. Current evidence supports the use of PBM for managing treatment-related side effects such as chemotherapy-induced peripheral neuropathy, oral mucositis, radiation dermatitis, lymphedema, and post-surgical pain. In fact, PBM is increasingly used in hospital oncology settings specifically for these indications. In such cases, PBM is not directed at tumor tissue itself, but rather at surrounding or distant structures to support symptom control and tissue resilience.

It is critical to emphasize that PBM is not a cancer treatment, nor should it ever be presented as such. It does not cure cancer, shrink tumors, or replace oncology care. Its role is supportive and adjunctive—focused on symptom management, functional improvement, and patient comfort. Clear communication with the patient, careful documentation, and coordination with the oncology team are essential components of responsible care.

From a practical standpoint, clinicians should use conservative dosimetry, avoid direct irradiation over known malignant lesions, and monitor patient response closely. When uncertainty exists, erring on the side of caution and seeking medical clearance is prudent.

In summary, a history of cancer or even active cancer does not automatically disqualify a patient from receiving Class 4 laser therapy. When applied thoughtfully, ethically, and within defined clinical boundaries, PBM can be a safe and valuable tool to improve quality of life in cancer patients and survivors alike.

Again…if the patient, their spouse, family, etc expresses any concerns about the cancer patient receiving laser therapy, err on the side of caution and do not treat.