Early detection, tx challenge skin cancer

April 1, 2005

New Orleans — One of the most important factors in achieving success in the treatment of skin cancers is recognizing which lesions are at highest risk for recurrences, extensive subclinical spread and metastasis, according to Timothy S. Brown, M.D., associate professor, University of Louisville"s division of dermatology.

New Orleans - One of the most important factors in achieving success in the treatment of skin cancers is recognizing which lesions are at highest risk for recurrences, extensive subclinical spread and metastasis, according to Timothy S. Brown, M.D., associate professor, University of Louisville's division of dermatology.

"Dermatologists should be aware of the several variables that suggest recurrence of basal cell carcinomas. They are location, histologic subtype, tumor size and depth, perineural involvement, and degree of immunosuppression,"Dr. Brown tells Dermatology Times

Dr. Brown discussed the means by which to successfully manage serious skin cancers at the 63rd Annual Meeting of the American Academy of Dermatology (AAD) here.

Highest-risk locations for non-melanoma skin cancers include the central face, eyelids, eyebrows, periorbital area, nose, lips, preauricular and postauricular areas and ears. The subtypes most likely to have extensive spread include micronodular, infiltrating, morpheaform and basosquamous types. Dr. Brown says lesions over 2 cm in size are defined as high risk, and, though it's often not considered, the depth of tumor invasion is a helpful tool in defining high-risk tumors.

"In addition to those in high-risk locations, tumors with perineural invasion and those occurring in immunosuppressed patients are at high risk for recurrences," he says.

Moving to squamous cell carcinomas (SCC), Dr. Brown says dermatologists should be aware of their high-risk locations: Ears, nasolabial fold, inner canthi, periorbital area, temple and lip/mucosa.

"SCC also arises in scars and ulcers," he says.

In addition to location, Dr. Brown notes that high-risk SCC tumors are often indicated by one or more characteristics.

"Indications for high-risk SCC tumors include the tumor's anatomic site, architectural pattern, the depth and level of invasion, diameter, differentiation, growth rate, immune status, perineural invasion and the extent of previous treatment," he says. "Sentinel lymph node biopsy is now being used to help detect micrometastatic disease in those high-risk squamous cell carcinomas," he adds. "Sentinel lymph node biopsy has been used successfully in conjunction with Mohs micrographic surgery to treat these high-risk lesions."

Care of these patients should focus on a combination approach, Dr. Brown says, citing a retrospective chart review of 74 patients with previously untreated metastatic SCC.

"Of these 74 patients, 52 were treated with a combination of neck dissection and radiation therapy, 13 were treated only with neck dissection, and nine with only radiation therapy," he says. "The patients who underwent the combined therapy had the lowest relapse rate - 15 percent - and a significantly better disease-free survival rate."

Lesions that have perineural invasion or that extend deeply to the fascia should be treated aggressively with Mohs micrographic surgery followed by postoperative radiation therapy, Dr. Brown says.

"For difficult patient subsets such as those immunosuppressed or those with basal cell nevus syndrome, combination therapies using surgery, topical or systemic retinoids, photodynamic therapy and biologic immune response modifiers are prudent," he says.

Dr. Brown says dermatologists should also play a key role in caring for the transplant patient.

"This year alone, more than 24,000 solid organ transplants will be performed in the United States," he says. "Currently, fewer than one in five transplant patients are being followed by a dermatologist. This high-risk group has a 65-fold increased risk of developing squamous cell carcinomas, a 10-fold risk of basal cell carcinomas, a 20-fold risk of melanomas and an 84-fold risk of Kaposi's sarcoma."

Dr. Brown cites one reported series of cardiac transplant patients in Australia in which more than one-fourth of the patients died of skin cancer after four years.

To illustrate the potential morbidity of skin cancer, Dr. Brown cites some sobering statistics.