04 Malignant Skin Lesions

It is particularly useful in treating morpheaform

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Unformatted text preview: ination of frozen sections to control surgical margins. It is particularly useful in treating morpheaform BCCs, recurrent BCCs, and BCCs in high-risk sites (with 5-year cure rates approaching 95%).13 Nonsurgical modalities available for treatment of BCC include radiotherapy, photodynamic therapy, and the application of topical agents (e.g., 5-fluorouracil [5-FU], imiquimod, and intralesional interferon alfa [IFN-α]). Radiation therapy is generally reserved for elderly patients with extensive lesions that preclude excision; 5-year cure rates in this population approach 90%.14 Photodynamic therapy involves the application of a 20% emulsion of δ-aminolevulinic acid to the lesion, followed by exposure to light in the wavelength range of 620 to 640 nm.This therapy is based on the uptake of the porphyrin metabolite by the tumor with subsequent conversion to protoporphyrin IX, which results in destruction of the tumor in the presence of light.10 The response rates observed with photodynamic therapy are somewhat lower than those observed with other therapies: the overall clearance rate is 87%, but the clearance rate for nodular BCC is only 53%.15 5-FU, in the form of a 5% cream, may be used in the management of multiple BCCs of the trunk and limbs. Imiquimod is also given in a 5% cream to treat BCCs, with clearance rates ranging from 70% to 100%.16 INF-α may be administered directly into the lesion; in a series of 140 patients treated in this manner, a 67% cure rate was reported.17 b Figure 1 Shown are (a) a typical basal cell carcinoma and (b) a morpheaform basal cell carcinoma. © 2006 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 3 BREAST, SKIN, AND SOFT TISSUE a 4 Malignant Skin Lesions — 3 b Figure 2 Shown are squamous cell carcinomas related to (a) radiation exposure and (b) sun exposure. Patients who have been treated for any skin cancer, including BCC, are at higher risk for the development of additional skin cancers and should therefore perform self-examinations at frequent intervals to check for suspicious lesions. Such patients should also receive counselling to reduce sun exposure, with the aim of limiting further damage from ultraviolet irradiation. High-risk patients (e.g., those with Gorlin syndrome and those who are receiving immunosuppressive therapy after renal transplantation) should be offered oral retinoid therapy in an effort to prevent the development of other nonmelanoma skin cancers.17 SQUAMOUS CELL CARCINOMA Incidence and Epidemiology SCC of the skin is the second most common form of nonmelanoma skin cancer overall. It is the most common tumor in elderly patients, probably as a consequence of cumulative doses of sun exposure over the course of their lifetimes. In white persons, the lifetime risk for the development of SCC is nearly 10%. The majority (50% to 60%) of cutaneous SCCs are found on the head and neck. In one series, nearly 50% of fatal cases of SCC occurred in patients in whom the lesion arose on the ear.18 The mortality assoc...
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This note was uploaded on 03/21/2011 for the course ONC 01 taught by Professor Dzodic during the Spring '11 term at Multimedia University, Cyberjaya.

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