Can the carbon dioxide laser completely ablate basal cell carcinomas? A histological study.

Carbon dioxide laser ablation has been advocated as an alternative therapeutic modality for basal cell carcinoma. This study examined the limitations of carbon dioxide laser ablation for BCCs by the formal excision and histological examination of the tumour bed, following laser therapy. We evaluated the tumour type and ablation depth required to ablate the tumours completely. Fifty-one selected BCCs, ranging from 4 to 35 mm, were ablated with a carbon dioxide laser combined with a microprocessor controlled optomechanical flash scanner. Clinically there were 21 superficial, 28 nodular and 2 infiltrative types. Complete ablation at the deep margin was associated with ablation depth (P = 0.006) and with tumour type (P = 0.01). Overall, all tumours of superficial subtype (found most commonly on the trunk) could be completely ablated reliably, provided they were lasered to a depth of the middle dermis or deeper. In contrast, nodular tumours could not reliably be ablated by this method. A small subset of nodular tumours less than 10 mm diameter, however, were all completely ablated provided they were lasered to a depth of the lower dermis or deeper, however this may result in delayed healing and scarring. We conclude that this fast modality is useful for the treatment of some BCCs provided strict selection criteria are met. Laser ablation would be most beneficial for patients with multiple superficial BCCs.