Though surgical removal of skin cancer is often the preferred first-line treatment, topical treatments may be appropriate for skin cancers of a certain type or stage. Although melanomas (the most serious type of skin cancer, often spreading to other parts of the body) usually require surgery, chemotherapy or radiation, actinic keratoses (pre-cancerous lesions) and non-melanoma skin cancers (including basal cell and squamous cell) may be treated topically.
5-fluorouracil (5-FU)
5-fluorouracil (5-FU) is one of the most commonly used treatments for actinic keratoses. It may also be used to treat Bowen's disease and small non-melanoma skin cancers. A topical cream, it requires application twice a day for three to four weeks and may cause severe redness, swelling or crusting that can take awhile to heal. According to the University of Maryland Medical Center (UMMC), there is some concern that 5-FU only clears the top skin layer of cancer, leaving or obscuring remaining cancerous tissue beneath the surface. It's also unclear whether 5-FU helps prevent recurrent or future skin cancers.
Diclofenac and Hyaluronan
Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID) used in topical gel form twice a day. Hyaluronan is a molecule that aids in the delivery of the medication to the skin. This combination gel causes less skin irritation than 5-FU, so it may be appropriate for those who can't tolerate harsher topical treatments. It's considered a moderately effective treatment option, according to UMMC, and results may not be evident for a month or more after treatment ends.
Imiquimod
Imiquimod is a topical cream that is FDA approved for the treatment of superficial basal cell cancer and actinic keratoses. Research is intended to determine its efficacy in treating squamous cell cancer and Bowen's disease (an early or pre-invasive form of squamous cell carcinoma). Imiquimod is recommended for use only when surgery is not indicated because, according to the National Cancer Institute, effectiveness is generally greater with surgery.
Ingenol Mebutate
Ingenol mebutate gel is a possible short-course topical treatment for actinic keratosis and non-melanoma skin cancer. According to the UMMC, it's derived from the Euphoria peplus plant and works by breaking down tumors and stimulating the production of antibodies. A study in the February 2009 issue of the Australasian Journal of Dermatology found that 0.05 percent ingenol mebutate gel is particularly efficacious in treating skin lesions. It's not intended for use on the face.
Phototherapy
Topical phototherapy is a nonsurgical laser light therapy used to treat actinic keratoses and non-melanoma skin cancers. The laser is combined with use of the drug aminolevulinic acid (ALA) to help destroy malignant cells on or just below the skin's surface.
According to the UMMC, phototherapy is as effective in treating actinic keratoses as 5-fluorouracil, and it achieves as satisfactory an outcome with regard to the skin's appearance. Phototherapy is also as effective as cryotherapy in treating non-malignant skin cancers; however, recurrence rates (up to 10 percent) are higher with phototherapy than with traditional surgical procedures.
References
- University of Maryland Medical Center: Treatment for Melanoma and Non-melanoma skin cancers
- "The Australasian Journal of Dermatology;" PEP005 (ingenol mebutate) gel, a novel agent for the treatment of actinic keratosis: results of a randomized, double-blind, vehicle-controlled, multicentre, phase IIa study; Siller G et al.; February 2009
- National Cancer Institute: FDA Approval for Imiquimod
