Photodynamic therapy against cryotherapy for superficial basal cell carcinoma

Cryotherapy is the oldest and cheapest of the destructive treatments and the one most often done in a general practice or a minor operations clinic. This multicentre randomised trial compared it against methyl aminolevulinate photodynamic therapy in primary superficial basal cell carcinoma: 60 patients with 114 lesions were given one session of photodynamic therapy and 58 patients with 105 lesions had cryotherapy with two freeze-thaw cycles, with re-treatment of incomplete responders at three months.

One hundred lesions treated with photodynamic therapy and 93 treated with cryotherapy were in complete response at three months after the last treatment and could be followed for recurrence. Over five years there was no difference in recurrence: 20 per cent after cryotherapy against 22 per cent after photodynamic therapy, p=0.86.

The difference was in the skin. An excellent cosmetic outcome was recorded in 60 per cent of the photodynamic therapy group against 16 per cent of the cryotherapy group, p=0.00078. Cryotherapy leaves a pale, often depressed scar with a permanent loss of pigment, which on a face is exactly what a person notices. Both results, the equality of recurrence and the inequality of appearance, matter: this is a trial in which the cheap old treatment holds its own on the outcome the doctor measures and loses on the outcome the patient sees.