Photodynamic therapy utilizing 10% ALA nano-emulsion gel and red-light for the treatment of squamous cell carcinoma in-situ on the trunk and extremities: Pilot study and literature update

Advances and perspectives in use of semisolid formulations for photodynamic methods

Although nearly 30 years have passed since the introduction of the first clinically approved photosensitizer for photodynamic therapy, progress in developing new pharmaceutical formulations remains unsatisfactory. This review highlights that despite years of research, many recurring challenges and issues remain unresolved. The paper includes an analysis of selected essential studies involving aminolevulinic acid and its derivatives, as well as other photosensitizers with potential for development as medical products. Among various possible vehicles, special attention is given to gelatin, alginates, poly(ethylene oxide), polyacrylic acid, and chitosan. The focus is particularly on infectious and cancerous diseases. Key aspects of developing new semi-solid drug forms should prioritize the creation of easily manufacturable and biocompatible preparations for clinical use. At the same time, new formulations should preserve the primary function of photosensitizers, which is the generation of reactive oxygen species capable of destroying pathogenic cells or tumors. Additionally, the use of adjuvant properties of carriers, which can enhance the effectiveness of macrocycles, is emphasized, especially in chitosan-based antibacterial formulations. Current research indicates that many promising dyes and macrocyclic compounds with high potential as photosensitizers in photodynamic therapy remain unexplored in formulation and development work. This review outlines potential new and previously explored pathways for advancing photosensitizers as active pharmaceutical ingredients (APIs).

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.

Surgical Excision Combined with Photodynamic Therapy for Squamous Cell Carcinoma Arising in Lupus Vulgaris

Cutaneous squamous cell carcinoma (SCC) is a common non-melanoma skin cancer (NMSC). Although most cutaneous SCC in people with lighter skin pigmentation as a result of sun damage, patients with underlying conditions such as skin ulcers and chronic inflammation-including conditions such as lupus vulgaris (LV) and chronic discoid lupus erythematosus-are also predisposed to developing SCC. Here we report a case of secondary SCC diagnosed in a 54-year-old patient with 20 years of lupus vulgaris without prior formal systemic treatment, a rarity in clinical practice. Two months ago, the patient developed papules on the right cheek that ulcerated and discharged purulent fluid. Laboratory tests revealed a positive TSPOT result and histopathological examination confirmed granulomatous lesions, supporting the diagnosis of SLE. However, a tissue biopsy unexpectedly revealed a moderately differentiated SCC of the keratinizing type. In this case, we performed surgical excision of the lesion followed by cosmetic closure and adjuvant photodynamic therapy (PDT). Concurrently, the patient underwent systemic anti-tuberculosis treatment. At 6 months post-treatment, no tumour recurrence was observed and the rash associated with lupus erythematosus had also resolved. The patient was satisfied with the treatment outcome.

Photodynamic Therapy for the Treatment of Bowen's Disease: A Review on Efficacy, Non-Invasive Treatment Monitoring, Tolerability, and Cosmetic Outcome

Bowen's disease represents the in situ form of cutaneous squamous cell carcinoma; although it has an excellent prognosis, 3-5% of lesions progress to invasive cutaneous squamous cell carcinoma, with a higher risk in immunocompromised patients. Treatment is therefore always necessary, and conventional photodynamic therapy is a first-line option. The aim of this review is to provide an overview of the clinical response, recurrence rates, safety, and cosmetic outcome of photodynamic therapy in the treatment of Bowen's disease, considering different protocols in terms of photosensitizers, light source, and combination treatments. Photodynamic therapy is a valuable option for tumors at sites where wound healing is poor/delayed, in the case of multiple and/or large tumors, and where surgery would be difficult or invasive. Dermoscopy and reflectance confocal microscopy can be used as valuable tools for monitoring the therapeutic response. The treatment is generally well tolerated, with mild side effects, and is associated with a good/excellent cosmetic outcome. Periodic follow-up after photodynamic therapy is essential because of the risk of recurrence and progression to cSCC. As the incidence of keratinocyte tumors increases, the therapeutic space for photodynamic therapy will further increase.

Long-term follow up of ALA 10% gel and red-light photodynamic therapy for the treatment of squamous cell carcinoma in situ

Photodynamic Therapy (PDT) with 10% aminolevulinic acid (ALA) gel and narrow-band red light has been previously shown to be safe and effective for the treatment of squamous cell carcinoma in situ (SCCis) on the trunk and extremities. However, there is a paucity of data in the literature evaluating long-term disease recurrence after PDT. Hence, we performed a follow-up study in which nine of the original twelve patients from our pilot study returned 29-40 months after their last PDT treatment. All patients were clinically clear of disease and only one of seven patients biopsied had residual disease, indicating a long-term clearance rate of 88%. Cosmetic outcomes and patient satisfaction were favorable. Our data supports that red-light PDT with 10% ALA gel can achieve long-term clinical and histopathologic disease clearance and is a viable alternative to surgery for select SCCis.

Photodynamic Therapy Using Intense Pulse Light to Treat an HIV Patient With Perianal Squamous Cell Carcinoma: A Case Report

Anogenital warts are considered one of the most common sexually transmitted infections caused by the human papillomavirus (HPV). One of the primary considerations with HPV is the virus’s high rate to develop into squamous cell carcinoma (SCC). SCC is one of the leading causes of skin cancer with a variety of treatment options. The gold standard of treatment for SCC is surgical excision. Complications may arise for those that are considered immunocompromised, or lack of efficacy may be taken into consideration for nonsurgical approaches. Herein, we suggest prompt diagnosis and treatment with photodynamic therapy (PDT) of HPV lesions to prevent disease progression and reoccurrence.

The patient is a 54-year-old male nonsmoker with a past medical history of squamous cell carcinoma and HIV and presented with a perianal rash. Additionally, he confirmed associated symptoms of itchiness, irritation, and pain. At the time of his appointment, his CD4 count was 121 cells/µL, and he stated he was compliant with his antiretroviral therapy. Based on history and physical examination, the patient was empirically treated with oral fluconazole and topical nystatin-triamcinolone for two weeks. At follow-up, symptomatology worsened, and a biopsy was performed. Squamous cell carcinoma in situ was confirmed histologically. A secondary bacterial skin infection developed at the biopsy site. At this point, PDT was recommended due to compromised tissue and further risk of infection.

At present, a gold standard of care for HPV infection does not exist. Prompt diagnosis and treatment of these lesions are important to recognize due to the high risk of the development of squamous cell carcinoma. Complications of secondary bacterial infections can arise with current treatment for squamous cell carcinoma, particularly in the immunocompromised. Non-surgical approaches for HPV have been less than desirable with higher recurrence rates of HPV lesions. Herein, we suggest the consideration of PDT treatment for HPV and SCC.