[Solar keratosis: from precancerous lesion to pre-invasive squamous cell carcinoma--therapeutic approach with a bioinductive method].

BACKGROUND: Solar keratoses are precancerous lesions in chronically UV-damaged skin with histological features consistent with pre-invasive squamous cell carcinoma. They require therapeutic intervention in order to prevent progression towards invasive carcinoma. Treatment options include topical medications and destructive methods. We report on a new approach--topical bioinductive therapy with imiquimod 5% cream.

PATIENTS AND METHODS: In a prospective case series, 7 patients with solar keratoses have been treated with topical imiquimod 5%. The cream was applied 5 days/week over 2 weeks. After end of treatment, the outcome was assessed at regular control visits and, in some cases, histologically confirmed. One patient was followed up as untreated control.

RESULTS: In 6 of the 7 treated patients, the lesions cleared completely; one patient did not respond. The patients did not show new solar keratoses during a follow-up period of about 2 years. The untreated patient showed spontaneous clearance of his keratoses. Local skin reactions during treatment included erythema, oedema and erosions in varying degrees, all of which completely resolved.

CONCLUSIONS: Bioinductive therapy with imiquimod 5% cream represents a promising therapeutic approach for cutaneous precancerous lesions such as solar keratoses.