Photodynamic therapy for superficial basal cell carcinomas: Clinical features of partial responses and recurrences

Background: Basal cell carcinoma (BCC) is one of the most common skin cancers. Photodynamic therapy (PDT) is a first line therapy option for superficial BCCs, providing good response and low side effects. The aim of current study is to evaluate the clinicopathological features associated with partial responses or recurrences of BCCs treated with one cycle-PDT (two sessions, one week apart). Methods: Superficial BCCs treated with PDT between 2016 and 2019 were analyzed. At the 6-month follow-up visit, BCCs were subdivided in “high clearance” or “partial response”, based on clinical and/or dermoscopic examination. “High clearance” lesions underwent 24-month follow-up visit and were assigned to “sustained clearance” or “recurrence” groups. Information about age, sex, site, size of lesions, skin biopsy and multiple lesions were collected and the association with the outcomes were estimated with multivariable logistic models. Results: 234 superficial BCCs from 216 patients were analyzed. At the 6-month follow-up visit, 171 out of 234 BCCs (73%) presented a “high clearance”, while 63 lesions (27%) showed a “partial response”. 28 out of 171 high clearance BCCs (16%) presented a recurrence within 24 months. When “partial response” is compared with the “high clearance” or “sustained clearance” group, a significant difference in mean superficial size of lesions is detected, with higher values in “partial response”. Head and neck BCCs have a double risk of recurrence within 24 months. Conclusions: PDT is a good therapeutic option for superficial BCCs, even though BCCs of head and neck have a higher risk of recurrences and larger BCCs could need a supplementary treatment.