RESUMEN
BACKGROUND: Gorlin Syndrome (naevoid basal cell carcinoma syndrome, NBCCS) predisposes the patient to the development of basal cell carcinomas (BCCs) throughout their life. The standard treatment for isolated lesions is surgical excision. However, when numerous surgical procedures are required over time, the patient can be left with multiple disfiguring scars. Photodynamic therapy (PDT) offers a non-invasive treatment option for patients with this condition, in which ionizing radiation is contraindicated. This study evaluates PDT as a treatment modality for Gorlin Syndrome and compares the treatment response of Gorlin-related basal cell carcinomas with that of the sporadic lesions. METHODS: In this un-randomized study, basal cell carcinomas in 25 Gorlin syndrome patients (with 36 lesions) and 145 sporadic patients (with 189 lesions) were treated by photodynamic therapy, using δ-5-aminolaevulinic acid (ALA) as a photosensitizer and 100Jcm(-2) of red light (630±15nm). The maximum thickness of the BCC was measured by 20MHz pulsed ultrasound prior to treatment and again 4-6 weeks and 12 months following treatment. The response of Gorlin syndrome lesions was compared to those in the overall sporadic population and then to a subpopulation matched as closely as possible for age, lesion thickness and site. RESULTS: For both populations, the average pre-treatment BCC thickness by US was 1.5mm (overall range 0.3-5.3), and the average thickness at 4-6 weeks post-treatment was 0.5mm (overall range 0-4.3). Those BCC less than 1.5mm thick prior to treatment were significantly more likely to have no US evidence of disease at 4-6 weeks than and were more likely to be controlled at 12 months. CONCLUSIONS: The average response to ALA PDT of Gorlin syndrome-related BCC closely resembles that for the sporadic population, with the same wide range of responses for a given dose. Ultrasound parameters measured at treatment and at 4-6 weeks post-treatment aid prediction of outcome and necessity for further treatment.
RESUMEN
Photodynamic therapy (PDT) has been associated anecdotally with good quality healing and an absence of scar formation. Our previous studies, examining the levels of the collagen specific molecular chaperone Hsp47, have noted differences in the response after photodynamic therapy and hyperthermia at both the transcriptional and translational levels. In the present study the levels of Hsp47 after exposure to two chemotherapeutic agents (bleomycin and mitomycin). ionising radiation, hyperthermia and haematoporphyrin ester (HpE) mediated PDT were compared in both mouse and human fibroblast cell lines. A rapid assay for soluble collagen has also been used to quantify soluble collagen levels at early time points after treatment. Peak Hsp47 levels were found to correlate well with peak collagen levels. The results show that the levels of collagen measured in vitro are elevated in modalities associated with scarring in vivo but not after HpE-PDT.