Nonmelanoma skin cancers

Las Vegas

- Nonsurgical modalities can provide safe, effective treatment for carefully selected low-risk nonmelanoma skin cancers, an expert says.

National Comprehensive Cancer Network guidelines for treating basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) note that evidence-based literature indicates that surgery is the most effective therapeutic option for these tumors, says Abel Torres, M.D., J.D., professor and chair of dermatology, Loma Linda University School of Medicine, California. These guidelines also recommend nonsurgical options including cryotherapy, photodynamic therapy, topical and intralesional therapies only for low-risk patients or where surgery is contraindicated or impractical.

However, Dr. Torres tells Dermatology Times, no consensus guidelines for treating actinic keratoses (AKs) exist. Although AKs represent the first visible sign of UV-induced cellular damage, he says, "If you treat the lesion alone, you’re only getting the tip of the iceberg and leaving the rest behind."

Moreover, he says AK and SCC represent different parts of a single disease continuum. As such, he says physicians should direct treatment toward the entire disease continuum, and the entire field wherein subclinical lesions may lie.

Among topical agents, 5-fluorouracil (5-FU, Carac; Dermik/Sanofi-Aventis) is indicated for AKs and superficial BCC (the latter requiring a five percent concentration applied for up to 12 weeks), and Dr. Torres says it’s especially recommended for multiple lesions or difficult treatment sites.

Somewhat similarly, he notes that in clinical trials in patients with at least five AK lesions, treatment for 90 days with diclofenac sodium gel (Solaraze, PharmaDerm) resulted in complete clearance for 34 to 47 percent of patients at 30 days post treatment.

Aldara Cream (imiquimod, Graceway), on the other hand, gained approval for treating both AKs (non-hypertrophic and subclinical) and superficial BCC in 2004. Because their mechanisms of action differ, Dr. Torres recommends imiquimod and 5-FU as sequential strategies, or as alternatives in patients with past histories of 5-FU use.

Furthermore, he says recent gene expression studies have shown that subclinical mutations persist after clinical clearing with 5-FU, while imiquimod treatment achieves normalization of mutations and tumor suppressor and promoter genes.

Therefore, he says there is perhaps good reason for using both agents together. Additionally, both have shown promise as adjuncts to Mohs surgery for nonmelanoma skin cancers, he says. DT

Disclosure: Dr. Torres reports prior or current financial relationships with Valeant, Lucid, Graceway and 3M.