Can intraepidermal carcinoma on the lip be treated with Metvix (methyl 5-aminolevulinate)?

From the Guidelines

Intraepidermal carcinoma on the lip can be effectively treated with Metvix (methyl 5-aminolevulinate) through photodynamic therapy (PDT). This treatment approach is supported by the British Association of Dermatologists and British Photodermatology Group guidelines for topical photodynamic therapy 2018, which recommends Metvix for non-hyperkeratotic actinic keratoses, squamous cell carcinoma in situ, and superficial basal cell carcinomas 1.

Key Considerations for Treatment

• The treatment involves applying a thin layer of Metvix cream to the affected area, allowing it to absorb, and then exposing the area to a specific wavelength of red light.
• Special care must be taken to protect the surrounding normal tissue, especially when treating sensitive areas like the lip.
• Patients should be informed about potential side effects, including pain during illumination, redness, swelling, crusting, and increased sun sensitivity for a short period post-treatment.

Mechanism and Efficacy

• Metvix selectively accumulates in abnormal cells and becomes activated by the light source to produce reactive oxygen species that destroy the cancerous cells, as explained in the guidelines for topical photodynamic therapy 1.
• The procedure offers the advantage of excellent cosmetic outcomes, which is particularly important for visible areas like the lip.
• Follow-up evaluation is necessary to confirm complete clearance of the lesion, typically at 3 months post-treatment.

Clinical Application

• The use of Metvix for intraepidermal carcinoma on the lip is based on its approval for similar skin conditions, including squamous cell carcinoma in situ, and its mechanism of action that targets abnormal cells while sparing normal tissue 1.
• Clinicians should follow established protocols for the application of Metvix and the administration of photodynamic therapy to ensure optimal outcomes and minimize side effects.

From the Research

Intraepidermal Carcinoma on the Lip Treatment with Metvix

• Intraepidermal carcinoma, also known as Bowen's disease, is a form of squamous cell carcinoma that is limited to the epidermis.
• Metvix (methyl 5-aminolevulinate) is a topical photosensitizing agent used in photodynamic therapy (PDT) for certain non-melanoma skin cancers.
• According to 2, Metvix is licensed in Europe for use in PDT for superficial and nodular basal cell carcinomas, actinic keratosis, and Bowen's disease on the face and scalp.
• Studies have shown that Metvix-PDT is effective in treating Bowen's disease, with complete response rates ranging from 69% to 93% at 3 months 3.
• A case report published in 4 describes the successful use of Metvix-PDT in a patient with microinvasive squamous cell carcinoma of the lower lip, with complete clinical, dermoscopic, and histopathological clearance after 2 cycles of treatment.

Efficacy and Safety of Metvix-PDT

• Metvix-PDT has been shown to be effective in treating various non-melanoma skin cancers, including actinic keratosis, superficial basal cell carcinoma, and Bowen's disease 3, 5.
• The treatment is generally well-tolerated, with the most common side effect being local phototoxicity reactions, which are usually mild to moderate in intensity and resolve rapidly 5.
• Cosmetic outcomes with Metvix-PDT are excellent to good in the vast majority of patients, and are often judged to be better than with cryotherapy or surgery 3, 5.

Alternative Treatment Options

• Other treatment options for intraepidermal carcinoma on the lip include surgery, cryotherapy, and radiotherapy 6.
• Radiotherapy has been shown to be an efficacious option for select patients with early-stage squamous cell carcinoma of the lip, with a 5-year recurrence-free survival rate of 90% 6.