Dermatology Department of ABC Medical School, Santo Andre, Brazil.
Pathology Department of ABC Medical School, Santo Andre, Brazil.
J Dermatolog Treat. 2022 Mar;33(2):878-884. doi: 10.1080/09546634.2020.1789042. Epub 2020 Jul 7.
Actinic keratosis (AK) are pre-malignant lesions, precursors of squamous cell carcinoma (SCC). Normal skin adjacent to AK, may present initial mutations with potential risk for new neoplasms, currently known today as field cancerization (FC).
To evaluate the effectiveness of daylight photodynamic therapy (PDT) with methyl amino levulinate (MAL) based on clinical evaluation, histological examination and immunohistochemical expression of p53 and Ki67.
Thirty patients, over 35 years old, phototypes between I and III, presenting non-hypertrophic AK on the face or scalp. Two biopsies with 2 mm punch of the lesion and adjacent skin before and 60 days after daylight PDT were performed. Results: Improvement was seen in lesion thickness and Ki67. 19 (63.33%) lesions had atypia improvement with a -value <.05, showing efficacy in treatment. After daylight PDT, 22 (73.33%) patients showed satisfactory esthetic improvement.
The study shows that PDT has cellular and molecular effects that support its indication in the control of carcinogenesis, as it decreases atypia and controls the expression of Ki67, reducing the proliferation of atypical cells. However, its indication following this study is still mainly aimed at clinical improvement of the skin, at this moment, probably due to the sample size.
光化性角化病（AK）是一种癌前病变，是鳞状细胞癌（SCC）的前身。AK 相邻的正常皮肤可能会出现最初的突变，存在新肿瘤的潜在风险，目前被称为“场癌变（FC）”。
评估基于临床评估、组织学检查和 p53 和 Ki67 的免疫组织化学表达的日光光动力疗法（PDT）治疗甲基氨基酮戊酸（MAL）对 AK 的疗效。
共 30 例患者，年龄超过 35 岁，皮肤类型在 I 至 III 之间，面部或头皮有非肥厚性 AK。在日光 PDT 治疗前和治疗后 60 天，对病变和相邻皮肤用 2mm 穿孔器进行了两次活检。结果：Ki67 显示病变厚度和 Ki67 均有改善。19 个（63.33%）病变的异型性改善有统计学意义（-值<0.05），显示出治疗的有效性。日光 PDT 后，22 例（73.33%）患者的美学改善令人满意。
该研究表明 PDT 具有细胞和分子作用，支持其在控制癌变方面的应用，因为它可以减少异型性并控制 Ki67 的表达，减少异型细胞的增殖。然而，根据这项研究，其适应症主要还是针对皮肤的临床改善，目前可能是由于样本量的原因。
