Carcinogenic risks of Psoralen UV-A therapy and Narrowband UV-B therapy in chronic plaque psoriasis: a systematic literature review
ABSTRACT Oral 8-methoxypsoralen-UV-A (PUVA) and narrowband UV-B (NB-UVB or UVB TL-01) are effective and widely used treatments for chronic plaque psoriasis. Although the role of PUVA therapy in skin carcinogenesis in humans with psoriasis has been clearly demonstrated, there is still controversy regarding the risk of skin cancer with NB-UVB. Furthermore, there is no clear evidence about the maximum cumulative number of sessions not to be exceeded in a lifetime.
To assess the respective cutaneous carcinogenic risks of PUVA or NB-UVB in psoriasis; to estimate the respective dose-relationship between skin cancers and PUVA or NB-UVB; to estimate a maximum number of sessions for PUVA or NB-UVB not to be exceeded in a lifetime.
A systematic literature search was carried out in Medline, Embase and Cochrane Library databases from1980 to December 2010 in English and French, with the keywords 'Psoriasis' AND 'UVB therapy' AND 'UVA therapy' AND 'cancer' AND 'skin' OR 'neoplasm' OR 'cutaneous carcinoma' OR 'melanoma'.
Of 243 identified references, 49 published studies were included. Most of them (45/49) concerned PUVA therapy, with 41 assessing the risk of non-melanoma skin cancers (NMSC) following PUVA. All publications referring to the US prospective PUVA follow-up study revealed an increased risk of NMSC with the following characteristics: risk most pronounced for squamous cell carcinomas developing even with low exposures and increasing linearly with the number of sessions, tumors occurring also on non-exposed skin including invasive penile tumors, risk persisting after cessation of treatment. An increased risk of basal cell carcinomas was observed in patients receiving more than hundred PUVA sessions. The four prospective European studies selected in our review and most of the pre-1990 European and US retrospective studies failed to find a link between exposure to PUVA and skin cancer. Only the most recent cohorts, including three large long-term retrospective European studies comparing records with their respective national cancer registries reported on an independent increased risk of NMSC with PUVA, The risk was lower as compared to the US prospective PUVA follow-up study. Six studies assessed the risk of melanoma following PUVA therapy: two of the three US publications coming from the same PUVA prospective follow-up study revealed an increased risk with more than doubled incidence of both invasive and in situ melanoma among patients exposed to at least 200 PUVA treatments compared with patients exposed to lower doses, whereas the three retrospectives European studies, comparing the incidence of melanoma in PUVA users with national cancer registers, did not find any increased risk of melanoma. No increased risk of skin cancer was evidenced in the four studies specifically assessing the potential carcinogenic risk of NB-UVB.
There is an increased risk of skin cancer following PUVA, shown by both US and European studies. The greater risk measured by the US studies may be at least partly explained by high UVA dose exposure and the lighter phototypes of the treated patients. The lack of prospective studies in psoriasis patients treated with NB-UVB constitutes a barrier to the robust assessment of carcinogenic risk of this phototherapy technique.
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ABSTRACT: Phototherapy is a first-line option for the treatment of moderate to severe psoriasis. Systematic reviews indicate near comparable efficacy of the different forms of phototherapy. Localized phototherapy can be an adjunctive treatment of recalcitrant plaques during systemic treatment of psoriasis. More than 200 psoralen-UV-A therapy treatment sessions is associated with an increased risk of keratinocytic cancers, whereas no increased risk has been demonstrated for narrow-band UV-B therapy. The mechanism of action of phototherapy in psoriasis is via inhibition of keratinocyte proliferation; induction of apoptosis in keratinocytes, dendritic, and T cells; and inhibition of Th1 and Th17 pathways, but activation of Th2.Dermatologic Clinics 11/2014; 33(1). DOI:10.1016/j.det.2014.09.007 · 1.43 Impact Factor
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ABSTRACT: Phototherapy is an effective treatment option for a variety of dermatologic disorders, and the list of indications for its use continues to grow with advances in technology and our understanding of disease processes. Commonly used types of phototherapy include PUVA, broadband UVB, narrowband UVB, photodynamic therapy, and intense pulsed light therapy. Each therapeutic modality can have adverse acute and chronic effects on periocular and ocular structures, including the conjunctiva, cornea, crystalline lens, and retina. There are many types of protective eyewear options available, including goggles and contact lenses that can be used to prevent damage to ocular structures during phototherapy, particularly if eyelid closure is incomplete. Copyright © 2015 Elsevier Inc. All rights reserved.Clinics in Dermatology 04/2015; 33(2). DOI:10.1016/j.clindermatol.2014.10.017 · 1.93 Impact Factor
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ABSTRACT: Background8-methoxypsoralen-UV-A (PUVA) and narrowband UV-B (NB-UVB) are well established treatments for chronic plaque type psoriasis vulgaris. However, long term risks of PUVA therapy are premature skin ageing and squamous cell cancer.Objectives To develop a device for targeted ultraviolet (UV) therapy of psoriatic plaques with protection of the healthy adjacent skin to reduce the risk for premature skin ageing and squamous cell cancer.Methods28 patients with exacerbated psoriasis vulgaris were treated with the Digital Phototherapy Device skintrek® [skintrek® cream PUVA (n=8), skintrek® bath PUVA (n=11) and skintrek® UV-B (n=9)] or with conventional bath PUVA (n=9) and NB-UVB (n=4), respectively.ResultsThe local PASI score was significantly reduced from a mean of 6.25 at baseline to 2.75 at the end of therapy in the skintrek® cream PUVA group, from a mean 6.4 to 3.0 in the skintrek® bath PUVA group and from 5.5 to 2.0 in the skintrek® UV-B group. Skintrek® cream PUVA reduced the mean local PASI by 54% while skintrek® bath PUVA did so by 51% and skintrek® UV-B by 63%. Targeted skintrek® PUVA and skintrek® UV-B of inflamed psoriatic skin avoided skin pigmentation and were not inferior to conventional bath PUVA and NB-UV-B therapy regimes.Conclusions Targeted UV-therapy of psoriatic plaques with the Digital Phototherapy Device skintrek® is as effective as conventional cream and bath PUVA as well as NB-UVB by simultaneously sparing the healthy adjacent skin and therefore (i) potentially reducing the carcinogenic risk, (ii) reducing premature skin ageing and (iii) avoiding tanning of healthy surroundings.This article is protected by copyright. All rights reserved.British Journal of Dermatology 10/2014; 172(3). DOI:10.1111/bjd.13464 · 4.10 Impact Factor