Is red light therapy safe for individuals with a history of skin cancer?

Safety of Red Light Therapy for Individuals with Prior Skin Cancer

Red light therapy is generally not recommended for individuals with a history of skin cancer due to potential risks of recurrence or new cancer development, although the evidence is limited.

Understanding Red Light Therapy and Skin Cancer Risk

Red light therapy (RLT) is a form of phototherapy that uses low-wavelength red light to treat various skin conditions. When considering its safety for patients with a history of skin cancer, we need to examine several factors:

Types of Light Therapy and Their Risks

1. Red Light Therapy vs. Photodynamic Therapy (PDT)

   • Red light therapy alone differs from PDT, which combines light with photosensitizing agents
   • PDT with red light is actually used to treat certain skin cancers, including:
     • Superficial basal cell carcinoma (BCC) 1
     • Squamous cell carcinoma in situ (Bowen disease) 1
     • Actinic keratosis (precancerous lesions) 1

2. Ultraviolet Light Therapy

   • UV phototherapy (UVB, PUVA) carries known skin cancer risks 1
   • Unlike UV therapies, red light does not directly damage DNA 2

Risk Assessment for Patients with History of Skin Cancer

Concerns for Patients with Prior Skin Cancer

1. Recurrence Risk Factors

   • Patients with prior skin cancer have significantly increased risk of developing additional skin cancers 1
   • The 5-year probability of developing another non-melanoma skin cancer after a first diagnosis is 40.7%, increasing to 82% after multiple occurrences 1
   • Risk of melanoma is also increased after diagnosis of squamous cell carcinoma (relative risk 3.62) 1

2. Photosensitivity Considerations

   • Patients with history of skin cancer may have increased photosensitivity 1
   • Some skin cancer types may be stimulated by light exposure 1

Evidence on Red Light Safety

Recent research on photobiomodulation (PBM) with red and near-infrared light suggests:

• Red light mainly enhances proliferation of healthy cells without clear influence on cell viability 2
• The same light parameters may actually reduce neoplastic cell proliferation and viability or have no effect 2
• Current clinical and preclinical evidence suggests PBM is oncologically safe for skin rejuvenation 2

However, this research is still limited and not specific to all skin cancer types.

Clinical Recommendations

For Patients with Prior Skin Cancer:

1. Avoid Red Light Therapy as a First Option

   • Given the increased risk of developing additional skin cancers in patients with prior skin cancer history 1
   • The potential for light therapies to affect cell behavior in unpredictable ways 2

2. If Red Light Therapy is Considered:

   • Conduct thorough skin examination before initiating treatment
   • Shield high-risk areas and previously affected sites 1
   • Regular monitoring with full skin examinations during and after treatment 1
   • Consider consultation with a dermatologist specializing in phototherapy

3. Alternative Approaches:

   • Consider FDA-approved treatments for the specific condition being targeted
   • Implement rigorous photoprotection measures including sunscreens, protective clothing, and sun avoidance 1, 3

Important Precautions

• Regular skin cancer screening is essential for anyone with prior skin cancer history 1
• Patients should be counseled about the importance of sun protection and avoidance of tanning beds 1, 3
• If red light therapy is used, treatment areas should be limited and carefully monitored

Conclusion

While red light therapy appears to have a better safety profile than UV-based phototherapies, the increased baseline risk of recurrent or new skin cancers in patients with prior skin cancer history warrants caution. Until more definitive research specifically addresses this population, alternative treatment options should be considered first.