Preliminary results on a proposed histopathological assessment of predictive factors for basal cell carcinoma recurrence after primary free margin excision.

Basal cell carcinoma (BCC) incidence is steadily increasing but therapeutic solutions remain limited and present a public health challenge. To identify predictive factors of BCC recurrence after primary free margin excision, with automated methods, by evaluating cell proliferation, the Hedgehog pathway activation and primary cilia. This case-control study included 32 patients (16 with recurrence occurring at least 6 months after complete resection, and 16 without recurrence) who underwent surgery for BCC. Formalin-fixed paraffin-embedded cutaneous resections were processed for immunohistochemistry or immunostaining with the following primary antibodies: mouse anti-MCM6, rabbit anti-ARL13B and rabbit anti-GLI1. BCC recurrence after free margin excision was significantly linked to a higher proliferative index (p < 0.001) and a lower cilia count (p = 0.041) in the primary lesion. No significant differences were observed regarding cilia length (p = 0.39) or GLI1-positive nuclei. The complex interplay between essential signaling pathways, cell proliferation and cilia requires further experimental investigations in the context of BCC recurrence. A higher proliferative index evaluated with MCM6 antibody could be a useful prognosis marker of BCC risk of recurrence. The lower cilia count in the primary lesion unveiled novel perspectives to understand BCC recurrence molecular mechanisms.