Calzavara-Pinton P G, Venturini M, Sala R, Capezzera R, Parrinello G, Specchia C, Zane C
Department of Dermatology, University of Brescia, Viale Europa 11, 25123 Brescia, Italy.
Br J Dermatol. 2008 Jul;159(1):137-44. doi: 10.1111/j.1365-2133.2008.08593.x. Epub 2008 Jul 1.
Photodynamic therapy (PDT) with methylaminolaevulinate (MAL) is an approved noninvasive treatment option for actinic keratosis and Bowen's disease (BD), two precursors of invasive squamous cell carcinoma (SCC).
To assess efficacy, prognostic features, tolerability and cosmetic outcome of MAL-PDT for the treatment of BD and SCC.
In total, 112 biopsy-proven lesions of BD and SCC in 55 subjects were treated in an outpatient setting. MAL cream (160 mg g(-1)) was applied for 3 h prior to illumination with a light-emitting diode source (wavelength range 635 +/- 18 nm; light dose 37 J cm(-2)). A second MAL-PDT session was given 7 days later. Complete response rate at 3 months after the last treatment, recurrence rate at the 24-month follow-up, and cosmetic outcome were recorded.
The overall complete response rates were 73.2% at 3 months and 53.6% at 2 years. Clinical thickness, atypia and lesion depth were significant predictors of the response at 3 months when using a univariate analysis (P < 0.001). A multivariate logistic regression model, with robust variance estimation, showed that cell atypia was the only statistically significant independent predictor of the treatment outcome at 3 months.
MAL-PDT may represent a valuable, effective and well tolerated treatment option with good cosmetic outcome for superficial, well-differentiated (Broders' scores I and II) BD and microinvasive SCC. In contrast, its use for superficial SCCs with a microinvasive histological pattern and for nodular, invasive lesions, particularly if poorly differentiated keratinocytes are present (Broders' scores III and IV), should be avoided.
外用甲基氨基乙酰丙酸（MAL）的光动力疗法（PDT）是一种已获批准的用于治疗光化性角化病和鲍恩病（BD）的非侵入性治疗方法，这两种疾病是浸润性鳞状细胞癌（SCC）的两种前驱病变。
评估MAL-PDT治疗BD和SCC的疗效、预后特征、耐受性和美容效果。
总共对55名受试者中112个经活检证实的BD和SCC病变进行了门诊治疗。在用发光二极管光源（波长范围635±18 nm；光剂量37 J/cm²）照射前3小时涂抹MAL乳膏（160 mg/g）。7天后进行第二次MAL-PDT治疗。记录最后一次治疗后3个月时的完全缓解率、24个月随访时的复发率以及美容效果。
3个月时总体完全缓解率为73.2%，2年时为53.6%。单因素分析时，临床厚度、异型性和病变深度是3个月时反应的显著预测因素（P<0.001）。一个采用稳健方差估计的多因素逻辑回归模型显示，细胞异型性是3个月时治疗结果唯一具有统计学意义的独立预测因素。
对于浅表性、高分化（布罗德斯评分I级和II级）的BD和微浸润性SCC，MAL-PDT可能是一种有价值、有效且耐受性良好的治疗选择，美容效果良好。相比之下，应避免将其用于具有微浸润组织学模式的浅表性SCC以及结节状浸润性病变，特别是存在低分化角质形成细胞的情况（布罗德斯评分III级和IV级）。
