Premalignant and Early Squamous Cell Carcinoma

Actinic keratoses (AK) are rough scaly patches that arise on chronically ultraviolet-exposed skin and can progress to keratinocyte carcinoma.

This analysis examined the literature related to the management of AK to provide evidence-based recommendations for treatment. Grading, histologic classification, natural history, risk of progression, and dermatologic surveillance of AKs are also discussed.

A multidisciplinary Work Group conducted a systematic review to address 5 clinical questions on the management of AKs and applied the Grading of Recommendations, Assessment, Development, and Evaluation approach for assessing the certainty of the evidence and formulating and grading clinical recommendations. Graded recommendations were voted on to achieve consensus.

Analysis of the evidence resulted in 18 recommendations.

This analysis is based on the best available evidence at the time it was conducted. The pragmatic decision to limit the literature review to English language randomized trials may have excluded data published in other languages or limited identification of relevant long-term follow-up data.

Strong recommendations are made for using ultraviolet protection, topical imiquimod, topical 5-fluorouracil, and cryosurgery. Conditional recommendations are made for the use of photodynamic therapy and diclofenac for the treatment of AK, both individually and as part of combination therapy regimens.

Photodynamic therapy (PDT) is a promising treatment modality for skin malignancies. Aminolevulinic acid (ALA)-PDT for the treatment of actinic keratosis (AK) has been well studied in Europe and North America. However, there have only been a few clinical studies that have evaluated ALA-PDT for the treatment of AK in Chinese patients.

The objective of our study was to determine the therapeutic response of Chinese patients with AK lesions to photodynamic therapy (PDT), and the histologic changes associated with PDT.

Forty-two patients with a total of 56 AK lesions on the face were enrolled in this study. After the application of 20% ALA under occlusion for 5 h, the lesions were illuminated by diode laser (λ = 630 nm; intensity 100 mW/cm²) for 30 min. All patients were reviewed at intervals of at least 2 weeks. One month after therapy, response to PDT was evaluated and treatment repeated if necessary.

At 1 month after PDT, a complete response was achieved in 85.71% of treated lesions. The remaining lesions received one or two additional PDT treatments, and were eventually cleared. Clinically, there was no significant scarring or pigmentary changes after therapy.

In this small study, PDT using topical ALA was demonstrated to be a safe and effective therapy for AK lesions with excellent cosmetic outcome. It is a promising treatment that merits further study in China.

Studies suggest that skin cancer aggregates within families; however, the risk of skin cancer associated with having an affected sibling or parent by subtype, tumor site, and age at diagnosis has not been established. The 2006 update of the Swedish Family-Cancer Database was used to calculate standardized incidence ratios (SIRs), representing the ratio of cancer risk among individuals with affected parents or siblings to the general population. Risk of invasive squamous cell skin cancer for individuals with an affected sibling or parent was increased between two- and three-fold compared with that in the general population. For in situ skin tumors, increased SIRs of 1.95–4.30 for squamous cell, Bowen's disease, and actinic keratosis were observed for individuals with affected siblings or parents, and SIRs were generally higher for tumors at sun-exposed versus covered sites. Finally, SIRs for in situ and invasive squamous cell skin cancer increased by increasing number of parental tumors (P≤0.01). In conclusion, having an affected sibling or parent was associated with an increased risk of skin cancer of varied subtypes compared with that in the general population, and for some subtypes, these familial risks were increased for tumors at sun-exposed sites or by an increasing number of parental tumors.