Printer-friendly format

In the United States, the incidence of both non-melanoma skin cancer and melanoma is increasing. According to the National Institutes of Health, more than 1 million cases of non-melanoma skin cancer were diagnosed last year. While traditionally considered a disease of older patients, new data suggests an increase in incidence among patients under age 40. A recent retrospective study from the Mayo Clinic showed a significant increase in basal cell carcinoma (BCC) incidence in women under 40. The rate was 13.4 per 100,000 in 1976-1979 and had increased to 31.6 per 100,000 in 2000-2003. The incidence of BCC in men under age 40 did not rise so precipitously; for the same time periods, incidence increased from 22.9 per 100,000 to 26.7 per 100,000. From the same study, the incidence of squamous cell carcinoma under age 40 was similar in both sexes, increasing from 0.6 per 100,000 to 4.1 per 100,000 during the same time periods.  Melanoma is the eighth most common malignancy in the United States. The incidence has increased from 1 per 1,500 in patients born in 1935 to 1 per 105 patients born in 1993.

Increasing incidence, especially among younger patients, underscores the need for educating the public regarding prevention and detection of non-melanoma skin cancer and melanoma. There is some debate about what age patients should begin having complete skin examinations and at what intervals they should be screened. However, the American Cancer Society recommends a complete skin exam beginning at age 20, with complete skin exams at three-year intervals until age 39. From age 40, the recommendation is a complete skin exam annually. A complete skin exam should include the patient removing all clothing and any concealing cosmetics. A full-spectrum halogen light or combined incandescent light should be used. The patient’s skin should be reviewed in a systematic manner including the scalp, palms and soles. Photographs are also helpful for documentation and to use at follow-up visits to detect changes.

The most common premalignant and malignant neoplasms identified on skin examination are actinic keratoses, BCC and SCC. Actinic keratoses are generally erythematous macules with thin to thicker overlying scale. They have a predisposition for sun-exposed areas and often occur as multiple lesions. The mainstay of treatment is cryotherapy. Topical therapeutic options include 5-flourouracil (5-FU), which is supplied in 1% and 5% cream formulations, and applied twice a day for two to five weeks depending on the response. There can be intense inflammation and edema with the use of this medication. Topical corticosteroids can minimize the inflammation but may also decrease the efficacy of the treatment.  Topical Imiquimod has been utilized in various regimens. Best practice based on multiple studies is a recommended regimen of once a day, five days a week, for six weeks.

Basal cell carcinomas are the most common neoplasms of the skin and are usually pearly papules with overlying telangiectasias on sun-exposed areas. There are several different histologic subtypes with superficial, nodular and morpheaform being the most common.  Nonfacial superficial BCCs can be treated topically with 5-FU or Imiquimod. Imiquimod is utilized once a day, five to seven days a week, for six weeks. Histologic clearance ranges from 77% to 80% with this regimen. Nodular and morpheaform BCCs require deeper treatment with electrodessication and curettage, excision or Mohs micrographic surgery.   

Squamous cell carcinomas are the second most common type of cutaneous neoplasm. They are erythematous papules or plaques with crusting, hyperkeratosis and erosion, again most common on sun-exposed areas. There are multiple histologic subtypes including in-situ, which is the least invasive and can be treated with electrodessication and curettage. An adequate biopsy specimen should be obtained for all suspected SCCs, especially on the head and neck region, so the presence of poorly differentiated features and perineural invasion can be evaluated. 

Mohs micrographic surgery is the best-practice treatment for basal and squamous cell carcinomas that occur on the H-zone of the head and neck, are larger than 2cm, are recurrent, or have evidence of perineural invasion. The recurrence rate with this method is 1%, which is the lowest recurrence rate of any available modality. The Mohs micrographic surgery clinic at Vanderbilt is set up to expedite the treatment of these types of patients. Mohs micrographic surgery allows for histopathologic evaluation of the entire margin of the surgical specimen. The specimen is processed horizontally to allow visualization of the margin and mapping to determine the location of residual tumor. Reconstruction is performed the same day after all residual tumor has been removed.

References
Christenson LJ et al.  Incidence of basal cell and squamous cell carcinomas in a population younger than 40 years.  JAMA 2005 Aug 10:294;681-90.
Schulze HJ et al.  Imiquimod 5% cream for the treatment of Superficial Basal Cell Carcinoma.  Br J of Dermatol  2005; 152(5):939-947.



Presented in Partnership by Nashville Medical News and Vanderbilt University Medical Center



May 2008



Click here for a PDF of this article

Tags:

None

Login and voice your opinion!