OBJECTIVES: Primary * Compare levels of apoptosis in patients with basal cell skin cancer treated with vs without imiquimod 5% cream. Secondary * Compare levels of apoptosis in patients treated with this drug on two different administration schedules. OUTLINE: This is a randomized, double-blind, placebo-controlled, parallel-group study. Patients undergo fine needle aspiration and punch biopsies of the target lesion. Patients are then randomized to 1 of 8 treatment arms and begin therapy within 30 days after biopsy. * Arm I: Patients apply topical imiquimod to the target lesion once every 12 hours on days 1 and 2 for a total of 4 doses. * Arm II: Patients apply topical placebo to the target lesion once every 12 hours on days 1 and 2 for a total of 4 doses. * Arm III: Patients apply topical imiquimod to the target lesion once every 24 hours on days 1-4 for a total of 4 doses. * Arm IV: Patients apply topical placebo to the target lesion once every 24 hours on days 1-4 for a total of 4 doses. * Arm V: Patients apply topical imiquimod to the target lesion once every 12 hours on days 1-4 for a total of 8 doses. * Arm VI: Patients apply topical placebo to the target lesion once every 12 hours on days 1-4 for a total of 8 doses. * Arm VII: Patients apply topical imiquimod to the target lesion once every 24 hours on days 1-8 for a total of 8 doses. * Arm VIII: Patients apply topical placebo to the target lesion every 24 hours on days 1-8 for a total of 8 doses. All patients undergo excision of the target tumor within 18-30 hours after the last topical treatment. Patients are followed at 7-14 days. PROJECTED ACCRUAL: A total of 48 patients (8 per treatment arm and 4 per placebo arm) will be accrued for this study.
DISEASE CHARACTERISTICS: * Histologically confirmed basal cell skin cancer * Superficial or nodular disease * No aggressive disease * At least 1 lesion at least 7 mm in diameter that meets the following criteria: * Primary tumor (no recurrent or previously treated disease) * Located on the scalp, face (including ears), trunk, or proximal extremities * Qualifies for surgical excision as primary therapy PATIENT CHARACTERISTICS: Age * 18 and over Performance status * Not specified Life expectancy * Not specified Hematopoietic * Not specified Hepatic * Not specified Renal * Not specified Cardiovascular * No evidence of a clinically significant or unstable medical condition that would adversely affect blood circulation Other * No dermatological disease (e.g., psoriasis or eczema) at the treatment site that may be exacerbated by treatment with imiquimod or interfere with examination * No febrile viral infection within the past 4 weeks * No evidence of a clinically significant or unstable medical condition that would adversely affect immune function PRIOR CONCURRENT THERAPY: Biologic therapy * More than 4 weeks since prior interferon, interferon inducers, or immunomodulators * No concurrent interferon, interferon inducers, or immunomodulators Chemotherapy * More than 6 months since prior anticancer chemotherapy * No concurrent anticancer chemotherapy Endocrine therapy * More than 4 weeks since prior oral or inhaled (more than 600 mcg/day for fluticasone or equivalent) corticosteroids * More than 4 weeks since prior topical steroids to the target tumor * Concurrent topical steroids in non-target areas are allowed provided amount used is ≤ 2 g of fluorinated steroids daily for \> 1 week or 6 g of beclomethasone for \> 1 week * No concurrent oral or inhaled corticosteroids Radiotherapy * Not specified Surgery * More than 4 months since prior biopsy Other * More than 4 weeks since prior immunosuppressive therapies * More than 4 weeks since prior cytotoxic or investigational drugs * No concurrent immunosuppressive therapies * No other concurrent cytotoxic or investigational drugs