Basal cell carcinoma (BCC) is the most common malignant skin lesion in white adults. It is a slow-growing tumour which despite low metastatic potential may cause significant local tissue destruction and patient morbidity. Methyl aminolevulinate cream plus photodynamic therapy (MAL-PDT) for BCC is currently approved for a procedure using 2 treatment sessions 1 week apart. This procedure is considered quite time- and resource-consuming. Introducing a single treatment session, with a new PDT session for treatment failures after 3 months, might represent an attractive simplification.

This randomised controlled single-blinded multi-centre study primarily aims to compare BCC lesion response rate of two treatment schedules: (a) 1 single treatment of Metvix-PDT with re-treatment of non-complete responders by 3 months, and (b) the usual schedule of 2 standard Metvix(R) PDT treatments 1 week apart.

Secondary objectives are to investigate the treatment response in relation to clinical and histological tumour characteristics such as tumour thickness, subtype and immunohistochemical markers.

Inclusion Criteria:

• male/female above 18 years of age
• written informed consent
• 1 or more primary histologically verified BCC, clinically assessed as of either superficial of nodular type

Exclusion Criteria:

• pregnancy
• breastfeeding
• Gorlin's syndrome
• porphyria
• xeroderma pigmentosum
• history of arsenic exposure
• known allergy to MAL
• concomitant treatment with immunosuppressive medication
• physical or mental conditions that most likely will prevent patients attending follow-up sessions