Background

There have been concerns that recurrences after noninvasive therapy for basal cell carcinoma (BCC) transform into a “more aggressive” histologic subtype.

Objective

We sought to evaluate the proportion of patients with a nonsuperficial treatment failure after noninvasive therapy for superficial BCC.

Methods

An observational study was performed using data from a single blind, noninferiority, randomized controlled trial (March 2008-August 2010) with 5-year follow-up in patients with primary superficial BCC treated with methylaminolevulinate–photodynamic therapy, 5-fluorouracil, or imiquimod. Data were used from 166 adults with a histologically confirmed treatment failure.

Results

A nonsuperficial subtype was found in 64 of 166 treatment failures (38.6%). Proportions with a more aggressive subtype than the primary tumor were 51.3% (38/74) for early and 28.3% (26/92) for later treatment failures (P = .003). The proportion of more aggressive early failures was significantly lower after imiquimod (26.3%) compared with methylaminolevulinate–photodynamic therapy (54.8%, P = .086) and 5-fluorouracil (66.7%, P = .011).

Limitations

There was limited information on the exact time of occurrence of treatment failures.

Conclusion

More aggressive treatment failure recurrences after noninvasive therapy for superficial BCC occur most often within the first 3 months posttreatment, probably indicating underdiagnosis of more aggressive components in the primary tumor rather than transformation.

中文翻译：

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浅表性基底细胞癌无创治疗后治疗失败的组织学亚型：一项观察性研究

背景

人们一直担心，无创治疗基底细胞癌（BCC）后的复发会转变为“更具侵略性”的组织学亚型。

客观的

我们试图评估浅表BCC无创治疗后发生非浅表治疗失败的患者比例。

方法

一项观察性研究使用的是一项单盲，非自卑，随机对照试验（2008年3月至2010年8月）的数据，对接受甲基氨基乙酰丙酸酯-光动力疗法，5-氟尿嘧啶或咪喹莫特治疗的原发性浅表BCC患者进行了5年的随访。使用了166名经组织学确认为治疗失败的成年人的数据。

结果

在166例治疗失败中有64例（38.6％）发现了一种非浅表的亚型。具有比原发性肿瘤更具侵略性的亚型的比例，早期治疗失败的比例为51.3％（38/74），晚期治疗失败的比例为28.3％（26/92）（P  = .003）。与氨基 乙酰丙酸甲酯-光动力疗法（54.8％，P  = .086）和5-氟尿嘧啶（66.7％，P = .011）相比，咪喹莫特治疗后更具侵略性的早期失败比例显着降低（26.3％）。

局限性

关于治疗失败发生的确切时间的信息有限。

结论

对于浅表BCC进行无创治疗后，更具侵略性的治疗失败复发通常发生在治疗后的前3个月内，这可能表明对原发肿瘤中较侵袭性成分的诊断不足，而不是转化。