Of the 8 histologically proven tumors, detection of PpIX proved to be ambiguous.

RATIONALE: Studying samples of tumor tissue in the laboratory from patients with nonmelanoma skin cancer that has been treated with topical aminolevulinic acid may help doctors predict how patients will respond to photodynamic therapy.

PURPOSE: This clinical trial is studying topical aminolevulinic acid in patients with nonmelanoma skin cancer.

OBJECTIVES:

• To evaluate the distribution and depth of protoporphyrin IX (PpIX) within different types of nonmelanoma skin cancers after topical aminolevulinic acid (ALA) administration.
• To obtain in vivo measurements of ALA-induced PpIX formation within different zones of the tumors as measured by fluorescence detection methods.
• To correlate the level of PpIX fluorescence detected by non-invasive optical measurements with morphological characteristics of the tumors.
• To establish a skin cancer tissue bank.

OUTLINE: Topical aminolevulinic acid (ALA) is applied to the center of the tumor surface. Patients then undergo punch tumor biopsy of the area where the ALA is applied followed by surgery to remove the tumor. Tissue samples are assessed for protoporphyrin (PpIX) levels by fluorescence confocal microscopy and hyperspectral imaging. Excess tumor tissue may be stored in a skin cancer tissue bank. Surface measurements (from a total of 5 surface sites) of PpIX fluorescence are taken at baseline and at 2 hours after ALA application using an optical fiber-based hand-held dosimeter.

DISEASE CHARACTERISTICS:

• Must have at least 1 biopsy-proven nonmelanoma skin cancer with a minimum diameter of 4 mm
• No tumors located on the eyelids, distal nose, cartilaginous portions of the ears, or lips

PATIENT CHARACTERISTICS:

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No known hypersensitivity to aminolevulinic acid or any component of this medication

PRIOR CONCURRENT THERAPY:

• Concurrent immunosuppressive or chemotherapeutic medications allowed
• Concurrent corticosteroids (taken by mouth or large doses taken with an inhaler) allowed
• Concurrent systemic retinoids (e.g., isotretinoin, acitretin, bexarotene, alitretinoin) or vitamin A allowed
• Other concurrent medications that may affect epidermal growth and differentiation (e.g., anti-EGFR monoclonal antibodies) allowed
• No concurrent participation in another clinical trial
• No concurrent topical treatment for the target tumor or for other nonmelanoma skin cancers
• No concurrent medical therapy or radiotherapy for other cancers

IPD will not be shared.