Beschreibung:
<jats:p><jats:bold>Background: </jats:bold> Photodynamic therapy (PDT) of superficial basal cell carcinoma (SBCC) acts as a biological response modifier or killing target cells, but sequential biological effects have not been reported in depth in humans.</jats:p><jats:p><jats:bold>Methods: </jats:bold> In 15 patients with SBCC treated with aminolevulinic acid (ALA)‐PDT, inflammatory infiltrate, apoptosis phenomena and tumor‐derived molecules were investigated on biopsies at baseline, and after 15 min and 4, 24, 48 and 72 h, by immunohistochemistry and ultrastructure.</jats:p><jats:p><jats:bold>Results: </jats:bold> Early apoptosis of keratinocytes was already observed at 15 min, while late apoptotic markers were maximally found at 24 h. Baseline mast cells tended to slightly increase up to 72 h; polymorphonuclear phagocytes significantly increased at 4 h but decreased at 24/48/72 h; on the contrary, lymphocytes and macrophages gradually increased starting at baseline. At baseline, SBCC cells expressed stem cell factor in all cases, and granulocyte‐monocyte colony‐stimulating factor, basic fibroblastic growth factor, interleukin (IL)‐8 and vascular endothelial growth factor in most cases. IL‐6 and monocyte chemoattractant protein‐1 were poorly expressed, and transforming growth factor‐beta was absent.</jats:p><jats:p><jats:bold>Conclusions: </jats:bold> We show a clear time‐dependent profile of apoptotic markers and inflammatory infiltrate composition in SBCC after ALA‐PDT. SBCC cells express cytokines and chemotactic molecules that are likely related to the recruitment of inflammatory cells.</jats:p>