Photodynamic Therapy of Nonmelanoma Skin Cancer with Topical Hypericum perforatum Extract—A Pilot Study

Abstract

Hypericin, the photoactive compound of Hypericum perforatum, is probably the most powerful photosensitizer found in nature. This compound has shown high potency in the photodynamic treatment of tumor cells. However, there is only limited knowledge regarding the photodynamic effect of hypericin on nonmelanoma skin cancer cells. The aim of this prospective study was to investigate the efficacy of photodynamic therapy with topical application of an extract of H. perforatum in actinic keratosis, basal cell carcinoma (BCC) and morbus Bowen (carcinoma in situ). The study was carried out on 34 patients--eight with actinic keratoses (AKs), 21 with BCC and five with Bowen's disease. The extract of H. perforatum was applied on the skin lesions under occlusion and that was followed by irradiation with 75 J cm(-2) of red light 2 h later. The treatment was performed weekly for 6 weeks on average. The percentage of complete clinical response was 50% for AKs, 28% in patients with superficial BCC and 40% in patients with Bowen's disease. There was only a partial remission seen in patients with nodular BCCs. A complete disappearance of tumor cells was found in the histologic preparation of 11% of patients with superficial BCCs and 80% in the patients with Bowen's disease. All patients complained of burning and pain sensations during irradiation. Although the results of this first clinical trial could be regarded as disappointing, there are still possibilities for improvement. Better preparation of the lesions, enhancement of hypericin delivery and other types of light exposure procedures could significantly improve the clinical outcomes of this relatively inexpensive treatment modality.

Dye Sensitizers for Photodynamic Therapy

“…Clinical trials have been performed to treat squamous cell carcinoma and basal cell carcinoma [77] but the results are unsatisfactory to date. Studies aimed at optimization and enhancement of dosage, drug and light delivery, and preparation of tested area have been undertaken [78]. …”

Time-resolved gene expression profiling of human squamous cell carcinoma cells during the apoptosis process induced by photodynamic treatment with hypericin

“…Although potentially promising from its properties (high tumour selectivity and efficiency) and proved in experiments with mice (3)(4)(5), only a few clinical data concerning the treatment of (pre)cancerous lesions of the skin exist. Hypericin was applied successfully on human skin carcinomas BCC (basal cell carcinoma) and SCC (squamous cell carcinoma) (6,7), but an extract of Hypericum perforatum, used in a clinical pilot study on actinic keratoses, BCC and Bowen's disease, showed only partial success (8). The results, however, are difficult to evaluate, since an extract of the whole plant may contain also inhibitory compounds.…”

Botanical Agents for the Treatment of Nonmelanoma Skin Cancer

“…A prospective pilot study by Kacerovská et al investigated the use of an extract of H. perforatum in combination with photodynamic therapy for BCCs, actinic keratoses, and Bowens disease (carcinoma in situ) [16]. A total of 34 patients were enrolled, 21 of which had BCCs.…”

“…They found complete clinical response for 28% of superficial BCC patients, and only partial remission was seen in nodular BCC patients [16]. By histology, a complete disappearance of cancer cells was found in 11% of the superficial BCCs [16]. All patients in the study complained of pain and burning during irradiation.…”