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Although ... used for treating superficial BCCs, (topical 5-FU) has not been well-studied for that indication. It is primarily used for actinic keratoses.
Las Vegas - Non-surgical treatments for basal cell carcinoma (BCC) offer welcome options for less invasive treatment of low-risk tumors, said Marc D. Brown, M.D., at the Fall & Winter Dermatology Conference.
The most commonly used approaches in the category of non-surgical treatments include the two topically applied medications 5-fluorouracil (Carac, Dermik; Efudex, Valeant; Fluoroplex, Allergan) and imiquimod 5 percent cream (Aldara, 3M) along with photodynamic therapy (PDT). Their potential advantages relative to surgery are that they avoid the need for local anesthesia and sutures, offer improved healing time, a better cosmetic result and the opportunity to treat subclinical disease. However, their cure rates may be lower than surgery, they provide no margin control, and they are not appropriate choices for high-risk BCCs characterized by aggressive histology, recurrence, larger size or high-risk location (ie., central mask area of the face), says Dr. Brown, professor of dermatology and oncology, University of Rochester.
"Surgical excision is the tried and true approach for treating BCC and the one for which we have the most information about cure and recurrence rates. However, as a physician who specializes in skin cancer treatment, I appreciate the opportunity to offer my patients some less invasive options as well. Discussing the pros and cons of all the approaches with respect to cure rates, adverse events, cosmesis, cost and simplicity allows patients to make an informed decision and select a modality that best satisfies their individual treatment goals," he explains.
"The clinical trials conducted to gain Food and Drug Administration approval included only a relatively small number of patients. Nevertheless, clinical experience indicates it works well for clearing superficial BCCs as well as SCC in situ, albeit with some discomfort and unpredictable patient compliance," Dr. Brown says.
Topical imiquimod just recently received FDA approval for the treatment of nonfacial, superficial BCCs measuring <2 cm in diameter, although it also has been studied for the treatment of smaller nodular BCCs along with a number of other types of skin cancer. Initial interest in that compound arose from knowledge that it locally induces cytokines and chemokines, particularly interferon, which was known to be effective as intralesional treatment for superficial BCCs.
Imiquimod allows for patient-administered treatment that is generally well-tolerated and results in excellent cosmesis with good cure rates. However, it does require a six-week course of application, is expensive and available studies show its histologic cure rate, reported to be in the 80 to 90 percent range, is inferior to surgery.
Nevertheless, Dr. Brown says that longer follow-up will probably demonstrate the clinical cure rate associated with imiquimod is even higher.
"Although the post-treatment biopsy may show some residual cancer cells, it may not be enough for tumor recurrence. Therefore, I would estimate that as we continue to follow patients, we will see that the five-year clinical cure rate for imiquimod treatment is at least 90 percent and perhaps higher," he says.
PDT for skin cancer has been around for some time, but is coming of age more recently with the FDA approval a few years ago of topical 5-aminolevulinic acid (5-ALA) 20 percent solution (Levulan, Dusa Pharmaceuticals) PDT using blue light (BLU-U Illuminator). That modality is indicated only for the treatment of minimally to moderately thick AKs of the face or scalp, but it has been reported effective in the treatment of superficial and nodular BCCs as well as Bowen's disease.
Due to a number of drawbacks, 5-ALA PDT did not gain widespread popularity.
"PDT was neither patient nor physician friendly. Its disadvantages included inconvenience, as patients had to have the topical photosensitizer applied one day and return the next for the light treatment. In addition, the treatment was uncomfortable and associated with photosensitivity," Dr. Brown explains.
Those issues have been addressed to some extent with new techniques based on shorter incubation times with alternative light sources. In addition, a different PDT regimen consisting of the methyl ester of 5-ALA (methyl aminolevulinate, Metvix, Galderma) used with a red light source (CureLight) allows for a relatively short incubation period with less treatment-associated pain.