Photodynamic therapy for Bowen's disease and squamous cell carcinoma of the skin

5-aminolevulinic acid photodynamic therapy for the treatment of basal and squamous cell carcinoma: A systematic review

BACKGROUND

5-aminolevulinic acid photodynamic therapy (ALA-PDT) is used off-label in the US to treat basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and Bowen disease (BD). We performed a systematic review to assess the efficacy and safety of published ALA-PDT protocols for these conditions.

METHODS

A PubMed search was conducted through August 8, 2024, to identify studies evaluating 10% or 20% ALA-PDT in BCC, SCC, and BD. Randomized controlled trials, observational studies, and case series with >5 patients were included. Quality assessment was performed using the Grading of Recommendations Assessment, Development, and Evaluation approach.

RESULTS

Fifty-eight studies were included in the analysis (BCC, n = 40; SCC, n = 9, BD, n = 27). Considerable heterogeneity was observed in ALA concentration, light sources, incubation times, and pretreatment strategies, precluding a standardized synthesis of outcomes. ALA-PDT achieved high clearance rates for superficial BCC and BD, with superior cosmetic outcomes compared to surgery or cryosurgery. Studies of ALA-PDT for SCC were limited with short follow-up times. Nodular BCC and SCC lesions demonstrated lower response rates, particularly with ALA-PDT monotherapy. Recurrence rates varied widely and were highest in patients with SCC. The most frequent adverse events were erythema, pain, and scaling.

CONCLUSIONS

This review provides a comprehensive summary of evidence-based ALA-PDT protocols for BCC, BD, and SCC, but published protocols are heterogeneous without a clear consensus. While ALA-PDT is effective, safe, and cosmetically favorable for less invasive tumors, protocol variability underscores the need for further randomized controlled trials to determine optimal treatment parameters.

Efficacy of interventions for cutaneous squamous cell carcinoma in situ (Bowen's disease): A systematic review and meta-analysis of proportions

BACKGROUND

Cutaneous squamous cell carcinoma in situ (Bowen's disease) is a precancerous condition confined to the epidermis of the skin. Despite the critical need for effective interventions to halt its progression, there remains a notable shortage of comprehensive data comparing the efficacy of various therapeutic approaches.

OBJECTIVES

This systematic review and meta-analysis endeavour to compare the different efficacies of interventions by investigating and synthesizing data from numerous trials.

METHODS

A pre-defined protocol was registered in PROSPERO (CRD42021242224, registration date: 16 April 2021). Systematic searches in Medline, Embase and Central, along with manual trial register searches, identified studies reporting lesion clearance rates (LCR), participant clearance rates (PCR) or recurrence rates (date of last search: 12 June 2024). Quality assessment followed guidelines from the National Heart, Lung, and Blood Institute (NHLBI). After the study arms were categorized into treatment groups and groups of study quality, the proportions were pooled using the generalized linear mixed model (GLMM) as meta-analytical method.

RESULTS

A comprehensive inclusion of 71 studies facilitated an evaluation of 3783 lesions for LCR, 1225 patients for PCR, 4073 lesions for lesion recurrence rates (LRR) and 740 patients for participant recurrence rates (PRR). Surgery demonstrated the highest LCR and PCR (0.97, 95% confidence interval (CI): 0.90-0.99) and the lowest LRR (0.04, 95% CI: 0.02-0.07).

CONCLUSIONS

This study provides a thorough overview of reported efficacy outcomes for practice-relevant interventions for Bowen's disease. Surgery outperformed other treatments for Bowen's disease. For the other intervention groups, it was not possible to show clear differences in effectiveness: LCR, PCR, LRR and PRR showed various treatment rankings, and the comparability was restricted by different numbers of studies between treatment groups and outcome measures, methodical and clinical heterogeneity. Further high-quality studies are needed to investigate practice-relevant interventions for Bowen's disease.

Durable Clearance Rate of Photodynamic Therapy for Bowen Disease and Cutaneous Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

BACKGROUND

Although surgery is the treatment of choice for Bowen disease (BD) and cutaneous squamous cell carcinoma (cSCC), nonsurgical treatments such as photodynamic therapy (PDT) may be preferred for select tumors. Previous meta-analysis have failed to gather strong evidence to recommend PDT.

OBJECTIVE

This study evaluates the effectiveness of PDT in the treatment of cSCC and BD for clearance rate (CR) after 1 year.

METHODS

A literature search of studies of biopsy-proven BD and cSCC treated with PDT was performed. Pooled CRs were estimated. Subgroup analyses were performed based on follow-up, treatment regimen, lesion size, and site.

RESULTS

Forty-three studies were included, enrolling 1943 BD lesions and 282 SCC lesions. Pooled CRs for BD and SCC were 76% (95% CI: 71%-80%; I2 = 78.9%) and 51% (95% CI: 35%-66%; I2 = 85.7%), respectively.

CONCLUSION

Our findings support the selective use of PDT for BD; however, patients should be advised of potential for recurrence. Although PDT can be used for certain cases of cSCC, the high rate of treatment failure necessitates close surveillance for residual or recurrent disease. Further studies are needed to justify the usage of PDT in the treatment of BD and cSCC.

A programme of research to set priorities and reduce uncertainties for the prevention and treatment of skin disease

Background

Skin diseases are very common and can have a large impact on the quality of life of patients and caregivers. This programme addressed four diseases: (1) eczema, (2) vitiligo, (3) squamous cell skin cancer (SCC) and (4) pyoderma gangrenosum (PG).

Objective

To set priorities and reduce uncertainties for the treatment and prevention of skin disease in our four chosen diseases.

Design

Mixed methods including eight systematic reviews, three prioritisation exercises, two pilot randomised controlled trials (RCTs), three feasibility studies, two core outcome initiatives, four funding proposals for national RCTs and one completed national RCT.

Setting

Secondary care, primary care and the general population.

Participants

Patients (and their caregivers) with eczema, vitiligo, SCC and PG, plus health-care professionals with an interest in skin disease.

Interventions

Our three intervention studies included (1) barrier enhancement using emollients from birth to prevent eczema (pilot RCT); (2) handheld narrowband ultraviolet light B therapy for treating vitiligo (pilot RCT); and (3) oral ciclosporin (Neoral®, Novartis Pharmaceuticals) compared with oral prednisolone for managing PG (pragmatic national RCT).

Results

Systematic reviews included two overarching systematic reviews of RCTs of treatments for eczema and vitiligo, an umbrella review of systematic reviews of interventions for the prevention of eczema, two reviews of treatments for SCC (one included RCTs and the second included observational studies), and three reviews of outcome measures and outcome reporting. Three prioritisation partnership exercises identified 26 priority areas for future research in eczema, vitiligo and SCC. Two international consensus initiatives identified four core domains for future eczema trials and seven core domains for vitiligo trials. Two pilot RCTs and three feasibility studies critically informed development of four trial proposals for external funding, three of which are now funded and one is pending consideration by funders. Our pragmatic RCT tested the two commonly used systemic treatments for PG (prednisolone vs. ciclosporin) and found no difference in their clinical effectiveness or cost-effectiveness. Both drugs showed limited benefit. Only half of the participants’ ulcers had healed by 6 months. For those with healed ulcers, recurrence was common (30%). Different side effect profiles were noted for each drug, which can inform clinical decisions on an individual patient basis. Three researchers were trained to PhD level and a dermatology patient panel was established to ensure patient involvement in all aspects of the programme.

Conclusions

Findings from this programme of work have already informed clinical guidelines and patient information resources. Feasibility studies have ensured that large national pragmatic trials will now be conducted on important areas of treatment uncertainty that address the needs of patients and the NHS. There is scope for considerable improvement in terms of trial design, conduct and reporting for RCTs of skin disease, which can be improved through wider collaboration, registration of trial protocols and complete reporting and international consensus over core outcome sets. Three national trials have now been funded as a result of this work. Two international initiatives to establish how best to measure the core outcome domains for eczema and vitiligo are ongoing.

Trial registration

Current Controlled Trials Barrier Enhancement for Eczema Prevention (BEEP) (ISRCTN84854178 and NCT01142999), Study of Treatments fOr Pyoderma GAngrenosum Patients (STOP GAP) (ISRCTN35898459) and Hand Held NB-UVB for Early or Focal Vitiligo at Home (HI-Light Pilot Trial) (NCT01478945).

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 4, No. 18. See the NIHR Journals Library website for further project information.

Interventions for non-metastatic squamous cell carcinoma of the skin: systematic review and pooled analysis of observational studies

OBJECTIVES

To assess the effects of treatments for non-metastatic invasive squamous cell carcinoma (SCC) of the skin using evidence from observational studies, given the paucity of evidence from randomised controlled trials.

DESIGN

Systematic review of observational studies.

DATA SOURCES

Medline, Embase, to December 2012.

REVIEW METHODS

Observational studies of interventions for primary, non-metastatic, invasive, SCC of the skin that reported recurrence during follow-up, quality of life, initial response to treatment, adverse events, cosmetic appearance, or death from disease. Studies were excluded if data for primary cutaneous SCC was not separable from other data. Data were extracted independently by two reviewers. Meta-analysis was performed where appropriate using a random effects model to estimate the pooled proportion of an event with 95% confidence intervals.

RESULTS

118 publications were included, covering seven treatment modalities. Pooled estimates of recurrence of SCCs were lowest after cryotherapy (0.8% (95% confidence interval 0.1% to 2%)) and curettage and electrodesiccation (1.7% (0.5% to 3.4%)), but most treated SCCs were small, low risk lesions. After Mohs micrographic surgery, the pooled estimate of local recurrence during variable follow-up periods from 10 studies was 3.0% (2.2% to 3.9%), which was non-significantly lower than the pooled average local recurrence of 5.4% (2.5% to 9.1%) after standard surgical excision (12 studies), and 6.4% (3.0% to 11.0%) after external radiotherapy (7 studies). After an apparently successful initial response of SCCs to photodynamic therapy, pooled average recurrence of 26.4% (12.3% to 43.7%; 8 studies) was significantly higher than other treatments. Evidence was limited for laser treatment (1 study) and for topical and systemic treatments (mostly single case reports or small non-comparative series with limited follow-up).

CONCLUSIONS

Many observational studies have looked at different treatment modalities for SCC, but the evidence base for the effectiveness of these interventions is poor. Comparison of outcomes after different treatments should be interpreted cautiously owing to biases inherent in the types of study included, and lack of direct comparisons to enable the estimation of relative treatment effect. Further evidence is needed to develop a prognostic model and stratify individuals at high risk of developing SCC, to improve the evidence base for this common cancer and to optimise clinical management.

PROTOCOL REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO) registration number CRD42011001450.

Treatment of skin cancer and pre-cancer using topical ALA-PDT--a single hospital experience

Our hospital (Shanghai Skin Diseases & STD Hospital) started to study 5-aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) in 1996. So far, we have treated 76 cases of skin cancer and pre-cancer using topical ALA-PDT. They included squamous cell carcinoma (SCC), basal cell carcinoma (BCC), Bowen's disease (BD), mammary and extramammary Paget disease, actinic keratosis (AK) and erythroplasia of Queyrat. In this overview article, we would like to present several representative cases and discuss our experience.