Therapeutic effects of topical 5-aminolevulinic acid photodynamic therapy

Correlation of the ALA-PDT Treatment Efficacy and the HPV Genotype Profile of Genital Warts after Cryotherapy Failure and Podophyllotoxin Therapy in Male Patients

Background: Genital warts are the manifestation of the human papillomavirus (HPV) infection, which may last for weeks or months before the clinical presentation. The primary aim of the study was the correlation of the DNA HPV genotypes eradication with the treatment response in male patients with persistent genital warts. Methods: Twenty-one male patients (age range: 22–58) after failure of cryotherapy and podophyllotoxin treatment were enrolled in the study. Genetic tests (Real Time - PCR method) analyzed the presence of DNA-HPV before and 6 months after four sessions (4 weeks apart) of photodynamic therapy with 5-aminolaevulinic acid (ALA-PDT). The treatment efficacy was evaluated before each PDT session and at the end of the study. Results: The single HPV DNA type was present in 15/21 of the patients (13/15 HPV6). The high-risk HPV types were found in 8/21 subjects, of which 6/8 had several types. Six months after four sessions of PDT, complete response was found in 16/21 (76.19%; p = 0.0007) of patients, and DNA HPV clearance was found in 66.67% (p = 0.03). The eradication rate differed among patients with primary low-risk and high-risk HPV types—76.92% (10/13; p = 0.0003) and 50% (4/8; p = 0.05) respectively. Conclusion: ALA-PDT is an effective treatment even after the failure of previous modalities. The persistence of clinical lesions and high oncological risk HPV types should be an indication for treatment prolongation.

Susceptibility and Resistance Mechanisms During Photodynamic Therapy of Melanoma

Melanoma is the most aggressive malignant skin tumor and arises from melanocytes. The resistance of melanoma cells to various treatments results in rapid tumor growth and high mortality. As a local therapeutic modality, photodynamic therapy has been successfully applied for clinical treatment of skin diseases. Photodynamic therapy is a relatively new treatment method for various types of malignant tumors in humans and, compared to conventional treatment methods, has fewer side effects, and is more accurate and non-invasive. Although several in vivo and in vitro studies have shown encouraging results regarding the potential benefits of photodynamic therapy as an adjuvant treatment for melanoma, its clinical application remains limited owing to its relative inefficiency. This review article discusses the use of photodynamic therapy in melanoma treatment as well as the latest progress made in deciphering the mechanism of tolerance. Lastly, potential targets are identified that may improve photodynamic therapy against melanoma cells.