Skin tumors in the European PUVA Study

S1-Leitlinie zur UV-Phototherapie und Photochemotherapie

Die heilsame Wirkung des Sonnenlichts war teilweise schon im Altertum bekannt und fand in der zweiten Hälfte des 19. Jahrhunderts wieder zunehmend Beachtung. Den Beginn der modernen Phototherapien markiert die Entwicklung einer Apparatur zur ultravioletten Bestrahlung der Hauttuberkulose durch Finnsen zu Beginn des zwanzigsten Jahrhunderts. Zur Therapie von Hauterkrankungen finden beinahe ausschließlich die spektralen Bereiche unterhalb des sichtbaren Lichtes (ultraviolett) Anwendung. Seit den 1970er Jahren stehen zunehmend leistungsfähige künstliche Strahlenquellen bereit für die Therapie mit UVB, UVA und die Kombination von UVA mit Photosensibilisatoren (Photochemotherapie). Hohe strukturelle und prozedurale Qualitätsstandards sind unabdingbare Voraussetzung für die Durchführung einer gleichermaßen wirkungsvollen wie auch sicheren Phototherapie. Die Leitlinie formuliert den aktuellen Konsens führender Experten auf dem Gebiet der Phototherapie in Bezug auf die Indikationen für die jeweiligen Therapieverfahren, deren Gegenanzeigen und Nebenwirkungen und insbesondere für die Wahl der korrekten Dosis zu Beginn und im Verlauf einer Therapie sowie das Management von Nebenwirkungen.

Multiple skin cancers in patients with mycosis fungoides after long-term ultraviolet phototherapy

Phototherapy is a useful noninvasive therapy, but it can induce cutaneous malignant tumours, including squamous cell carcinoma (SCC) and basal cell carcinoma (BCC). We report on a 79-year-old man who had long-standing mycosis fungoides for 40 years, which had been treated with psoralen ultraviolet A therapy for 37 years at a dose of approximately 5000 J/cm² . Approximately 6 years before presentation, numerous types of cutaneous malignancies, including actinic keratosis, BCC and SCC, had begun to develop all over the patient's body. We hypothesized that he was experiencing a pathogenesis similar to patients with xeroderma pigmentosum (XP), and we therefore assessed his DNA repair capacity. Based on these investigations, the patient was eventually diagnosed as non-XP, even though we detected that his DNA repair capacity was slightly lower than that of normal controls, which may have led to the skin cancers. We speculate that multiple skin malignancies can be induced by long-term phototherapy in patients with slightly impaired DNA repair capacity.

Melanoma and non-melanoma skin cancer in psoriatic patients treated with high-dose phototherapy

OBJECTIVES

The carcinogenic effect of plus ultraviolet A (PUVA)-therapy in psoriatic patients has been widely demonstrated, while data on the safety of narrow band (311 nm) ultraviolet B (nb-UVB) are scarce. We investigated the occurrence of melanoma and non-melanoma skin cancer (NMSC) in psoriatic patients treated with nb-UVB or PUVA-therapy.

METHODS

This retrospective study included patients affected by psoriasis, who had been treated with nb-UVB or PUVA-therapy. Clinical data and phenotypic risk factors were collected and a total body examination was performed at a routine appointment during the study period.

RESULTS

We examined 92 patients (60 males and 32 females; mean age: 53.5 years, range: 20-83 years) treated with PUVA-therapy (42/92, 45%) or with nb-UVB (50/92, 55%) for 1-28 years (mean: 7.1 years). Among patients treated with PUVA, nine skin tumors (one melanoma, seven basal cell carcinoma (BCCs) and one squamous cell carcinoma (SCC)) were detected in 2/42 (4.7%) patients, while in the nb-UVB group, 14 skin tumors including two melanomas, four BCCs, and eight SCCs were diagnosed in 6/50 (12%) patients.

CONCLUSIONS

A noteworthy number of NMSC were diagnosed in this Mediterranean population of patients exposed to high-dose UV treatment. A thorough risk-benefit evaluation should always be done before UV treatment and patients should be carefully monitored for skin cancer during and after treatment discontinuation.

Cutaneous Carcinogenic Risk of Phototherapy: An Updated Comprehensive Review

Phototherapy is among the oldest and most highly effective treatment modalities available for moderate-to-severe psoriasis. However, concern regarding the potential carcinogenic risk associated with ultraviolet B (UVB) phototherapy and/or psoralen with ultraviolet A (PUVA) has been expressed by both providers and patients. The purpose of this review is to assess the cutaneous malignancy risks of UVB phototherapy and/or PUVA in all skin types, including Caucasian and non-Caucasian patients. We searched the MEDLINE database for original research articles regarding the skin cancer risk of phototherapy. A total of 61 articles were included. In Caucasians, an increased risk of squamous cell carcinoma with PUVA therapy was reported after >250 sessions, whereas studies among non-Caucasians did not show any increased risk. There was no convincing evidence of increased skin cancer risk associated with UVB phototherapy among all skin types. In view of the continued validation of its safety, phototherapy remains a valuable treatment option for patients with moderate-to-severe psoriasis.

Revisited the potential risks of carcinogenicity of phototherapy in patients with psoriasis

The article presents published data on the assessment of the risk of cancerogenicity of multiple courses of phototherapy methods such as PUVA therapy and UVB-311 in psoriatic patients. The authors analyzed the incidence of malignant skin neoplasms (squamous cell carcinoma, basal cell carcinoma, malignant skin melanoma) among psoriatic patients from different population groups taking into account the cumulative radiation doses and number of procedures.

The risk of squamous cell and basal cell cancer associated with psoralen and ultraviolet A therapy: a 30-year prospective study

BACKGROUND

By 1977, psoralen and ultraviolet A (PUVA) was established as a highly effective therapy for psoriasis. Because of concerns about potential long-term adverse effects, particularly cancer, the PUVA Follow-Up Study was established to assess long-term risk and benefits of PUVA.

OBJECTIVE

We sought to determine the association of certain squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) risk with exposure to PUVA.

METHODS

For nearly 30 years, this prospective cohort study of 1380 patients with psoriasis first treated with PUVA in 1975 to 1976 documented exposures and incident events including biopsy-proven skin cancers.

RESULTS

From 1975 to 2005, 351 of 1380 (25%) cohort patients developed 2973 biopsy-proven SCC and 330 (24%) developed 1729 BCCs. After adjusting for age, gender, and significant confounders, the risk of developing one or more SCC in a year was strongly associated with total number of PUVA treatments (350-450 vs <50 treatments, incidence rate ratio [IRR] = 6.01, 95% confidence interval [CI] = 4.41-8.20). When all tumors are included this risk is significantly higher (IRR = 20.92, 95% CI = 14.08-31.08). Corresponding risks for BCC were much lower (person counts IRR = 3.09, 95% CI = 2.36-4.06; tumor counts IRR = 2.12, 95% CI = 1.47-3.05).

LIMITATIONS

This was an observational prospective study of a cohort with severe psoriasis. An unknown factor associated with higher dose exposure to PUVA in our cohort that was not included in our analysis could account for the observed associations.

CONCLUSION

Exposure to more than 350 PUVA treatments greatly increases the risk of SCC. Exposure to fewer than 150 PUVA treatments has, at most, modest effects on SCC risk. Even high-dose exposure to PUVA does not greatly increase BCC risk. The risks of SCC in long-term PUVA-treated patients should be considered in determining the risk of this therapy relative to other treatments for severe psoriasis.

Large-scale, prospective, observational studies in patients with psoriasis and psoriatic arthritis: A systematic and critical review

Background

Observational studies, if conducted appropriately, play an important role in the decision-making process providing invaluable information on effectiveness, patient-reported outcomes and costs in a real-world environment. We conducted a systematic review of large-scale, prospective, cohort studies with the aim of (a) summarising design characteristics, the interventions or aspects of the disease studied and the outcomes measured and (b) investigating methodological quality.

Methods

We included prospective, cohort studies which included at least 100 adults with psoriasis or psoriatic arthritis. Studies were identified through searches in electronic databases (Pubmed, Medline, Cochrane library, Centre for Reviews and Dissemination). Information on study characteristics were extracted and tabulated and quality assessment, using a checklist of 18 questions, was conducted.

Results

Thirty five papers covering 16 cohorts met the inclusion criteria. There were ten treatment-related studies, only two of which provided a comparison between treatments, and six non-treatment studies which examined a number of characteristics of the disease including mortality, morbidity, cost of illness and health-related quality of life. All studies included a clinical outcome measure and 11 included patient-reported outcomes, however only two studies reported information on patient utilities and two on costs. The quality of the assessed studies varied widely. Studies did well on a number of quality assessment questions including having clear objectives, documenting selection criteria, providing a representative sample, defining interventions/characteristics under study, defining and using appropriate outcomes, describing results clearly and using appropriate statistical tests. The quality assessment criteria least adhered to involved questions regarding sample size calculations, describing potential selection bias, defining and adjusting for confounders and losses to follow-up, and defining and describing a comparison group.

Conclusion

The review highlights the need for well designed prospective observational studies on the effectiveness, patient-reported outcomes and economic impact of treatment regimes for patients with psoriasis and psoriatic arthritis in a real-world environment.

Currentaspects of psoriasis phototherapy

The review covers current aspects of ultraviolet therapy for patients suffering from psoriasis. It describes mechanisms of action as well as early and remote side effects of the current phototherapy methods. The review also presents data from literature about the risk of their cancerogenicity. It also discusses approaches to the optimization of phototherapy in view of risks and benefits for the patient.

Case of localized scleroderma successfully treated with bath psoralen and ultraviolet A therapy

The patient was a 12-year-old girl with linear scleroderma distributed on the right abdomen, dorsal aspect of the right thigh, lower leg and foot. The initial regimen of oral prednisolone and methotrexate, or i.v. methylprednisolone failed in the treatment of the scleroderma. Then bath psoralen and ultraviolet A therapy (bath-PUVA) therapy of 0.2 J-4.0 J/cm(2) daily to total doses 62.8 J/cm(2) combined with oral prednisolone was started. After bath-PUVA therapy, regression of the skin sclerosis was observed, the possible mobile range of the right ankle was increased and histological examination confirmed improvement of the sclerosis. The successful results of bath-PUVA therapy in this case suggest its utility for localized scleroderma.

Photosensitizing compounds in the treatment of psoriasis

Photosensitizers were first used to treat psoriasis 15 years ago when the phototoxic reaction of psoralens and UVA was found to induce remissions of the disease. The effect of this reaction on DNA, particularly the formation of cross-links, was thought to be the decisive event. Strong cross-linking agents such as 8-MOP, TMP and 5-MOP are clinically effective whereas most compounds which produce only monofunctional adducts are virtually ineffective. Orally administered 8-methoxypsoralen (8-MOP) is the most widely used compound. 4,5',8-Trimethylpsoralen (TMP) is poorly absorbed from the intestine but has marked efficacy when applied topically. 5-MOP may be a useful alternative to 8-MOP because it is less erythemogenic and does not cause nausea. These three furocoumarins appear to be similar photochemically and may introduce similar risks. However, the photobiological properties of furocoumarins can be modified by altering one or more parts of the molecule. Such modifications might yield effective analogues with reduced cytogenetic hazards. Several psoralens and angular furocoumarins are being tested for effectiveness combined with fewest long-term side-effects, especially carcinogenesis. Encouraging preliminary results have been obtained with 7-methyl-pyridopsoralen and 4,6,4'-trimethylangelicin. Other important approaches to increasing the safety of photochemotherapy may be the use of different photoactivating wavelengths or the introduction of new classes of photosensitizers.

Penile cancer

Penile cancer, while relatively rare in the western world, remains a disease with severe morbidity and mortality, not to mention significant psychological ramifications. Furthermore, the disease is observed with dramatically increased incidence in other parts of the world. A review of the literature has shown that the overwhelming majority of penile cancers are in situ or invasive squamous cell carcinomas, including a well-differentiated variant, verrucous carcinoma. Important predisposing factors are lack of circumcision, human papillomavirus infections, and penile lichen sclerosus, although other factors have occasionally been reported as well. Prevention, careful monitoring of patients at risk, and early diagnosis are essential to reduce the incidence of penile carcinoma and to provide a definitive cure. Public health measures, such as prophylactic use of circumcision, have proved successful but are controversial. Also, no standard therapeutic guidelines as to the best treatment strategy according to different stages, including efficacy of conservative nonsurgical modalities and indications for lymph nodal dissection, are available so far. It is common opinion that penile cancer is an emerging problem that deserves further investigations, and physicians, especially dermatologists, should be aware of this issue.

LEARNING OBJECTIVE

At the completion of this learning activity, participants should be familiar with penile carcinoma, its risk factors, its clinical and histologic presentation, and the treatments currently available for its management.

Effect of ethnicity on the risk of developing nonmelanoma skin cancer following long-term PUVA therapy

BACKGROUND

Research demonstrating an increased incidence of skin cancer with psoralen plus ultraviolet A (PUVA) therapy has reflected the Caucasian experience. Our objective was to review the literature on skin cancer risk associated with long-term PUVA therapy in non-Caucasians.

METHODS

Our analysis included 4,294 long-term PUVA patients in Japan, Korea, Thailand, Egypt, and Tunisia with a follow-up period of at least 5 years.

RESULTS

The relative risk of PUVA patients developing nonmelanoma skin cancer relative to general dermatology outpatients was 0.86 [CI 0.36-1.35].

CONCLUSIONS

There does not appear to be an increased risk of nonmelanoma skin cancer with long-term PUVA therapy in Asian and Arabian-African populations. Therefore, in phototherapy risk assessment, it is important to consider the patient's skin phototype and the potential protection that more pigmented skin may confer.

Determination of the minimal phototoxic dose and colorimetry in psoralen plus ultraviolet A radiation therapy

BACKGROUND

The use of an adequate initial dose of ultraviolet A (UVA) radiation for photochemotherapy is important to prevent burns secondary to overdosage, meanwhile avoiding a reduced clinical improvement and long-term risks secondary to underdosage. The ideal initial dose of UVA can be achieved based on the phototype and the minimal phototoxic dose (MPD). The objective measurement of constitutive skin color (colorimetry) is another method commonly used to quantify the erythematous skin reaction to ultraviolet radiation exposure. The aim of this study was to determine variations in MPD and constitutional skin color (coordinate L(*)) within different phototypes in order to establish the best initial dose of UVA radiation for photochemotherapy patients.

METHODS

Thirty-six patients with dermatological conditions and 13 healthy volunteers were divided into five groups according to phototype. Constitutional skin color of the infra-axillary area was assessed by colorimetry. The infra-axillary area was subsequently divided into twelve 1.5 cm(2) regions to determine the MPD; readings were performed 72 h after oral administration of 8-methoxypsoralen (MOP) followed by exposure of the demarcated regions to increasing doses of UVA.

RESULTS

The majority of the participants were women (73.5%) and their mean age was 38.8 years. The MPD ranged from 4 to 12 J/cm(2) in phototypes II and III; from 10 to 18 J/cm(2) in type IV; from 12 to 24 J/cm(2) in type V and from 18 to 32 J/cm(2) in type VI. The analysis of colorimetric values (L(*) coordinate) and MPD values allowed the definition of three distinctive groups of individuals composed by phototypes II and III (group 1), types IV and V (group 2), and phototype VI (group 3).

CONCLUSIONS

MPD and L(*) coordinate showed variation within the same phototype and superposition between adjacent phototypes. The values of the L(*) coordinate and the MPD lead to the definition of three distinct sensitivity groups: phototypes II and III, IV and V and type VI. Also, the MPD values bear a strong correlation to coordinate L(*) values. Mean MPD values described for each of the three major sensitivity groups were higher than the values commonly used in clinical settings for the different phototypes. Therefore, phototype alone is not a good parameter to define the initial UVA dose. MPD and colorimetry could be used in pre-treatment evaluation of patients who are to be submitted to photochemotherapy, in a non-invasive and more accurate way when compared with the classical phenotype clinical criteria.

A clinician's paradigm in the treatment of atopic dermatitis

Successful management of atopic dermatitis requires a multipronged approach that includes skin barrier function care, use of topical or systemic agents, and identification and elimination of precipitating or exacerbating factors. Because the origin of atopic dermatitis is multifactorial and trigger factors differ among patients, treatment plans must be specific to the individual patient. This article offers an example of a permutational, or flexible, treatment paradigm. The approach utilizes 4 topical regimens--high-potency topical corticosteroids, lowest effective potency topical corticosteroids, topical calcineurin inhibitors (TCIs), or topical corticosteroid/TCI combinations--as initial therapy in a variety of induction protocols, as determined by the severity of a patient's condition and history. The paradigm permits treatment to progress from a chosen induction therapy to maintenance therapy. During the patient's induction therapy, as soon as an acceptable level of clearance is achieved, therapy should be adjusted to a maintenance regimen, such as monotherapy with either a TCI or a lowest effective potency topical corticosteroid (the latter used intermittently) or an alternation of the two agents. If there is no clearance or positive response with the initial induction protocol, the clinician should move to one of the alternative regimens.

Ultraviolet and laser radiation safety

Both ultraviolet radiation and laser radiation occupy pmt of the Spectrum designated "optical radiation". Thus, measurement techniques are similar and the same organs (eyes and skin) are at risk from accidental exposure. However, the equipment used to produce ultraviolet and laser radiation differs substantially and the harm caused by each type of radiation is also different. Another significant difference arises from the fact that ultraviolet radiation is natural with associated general population exposure. Consequently, the present article reviews the current status of both ultraviolet and laser radiation with the material divided into two sections where each hazard is considered separately.

Iatrogenic skin cancer: induction by psoralen/ultraviolet A and immunosuppression of organ transplant recipients

Photochemotherapy (psoralen/UVA (PUVA)) is an efficient therapeutic tool for a wide range of skin diseases. Concern, however, exists regarding the long-term carcinogenic effects of this treatment modality and, as a consequence, is being used less frequently. PUVA remains an important treatment in our therapeutic armamentarium but must be used with caution in those patients with risk factors and cumulative dose exposure must be limited. PUVA-induced cancers show features in common with skin cancers induced by immunosuppressed organ transplant recipients. Tumours in the latter group of individuals are, however, much more aggressive and difficult to manage.

PUVAthérapie et cancers cutanés

INTRODUCTION

The benefits of PUVAtherapy in many dermatological affections are well known. Its carcinogenic role in the long term has been assessed varyingly in American and European series.

OBJECTIVE

The aim of this study was to assess the role of PUVA in the onset of cancers of the skin.

METHODS

Retrospective study of patients presenting with psoriasis and followed-up in the phototherapy unit of the Michallon Hospital in Grenoble since 1976 and having received more than 150 sessions of PUVA. The parameters studied were: age, gender, phototype, age at the time of the first irradiation, type of phototherapy administered, total number of sessions, concomitant treatments, administration of retinoids and the appearance of skin cancers with the interval before their onset after the first session, their localization and their histological type.

RESULTS

One hundred six patients were retained among the 152 who replied to the inclusion criteria. Having died or been lost to follow-up, forty-six patients were excluded. Fourteen patients had presented at least one cutaneous tumor with a total number of 35. Excluding the keratoacanthomas, 13 patients had a non-melanic cutaneous cancer with a total number of 32 tumors. Ten out of the 14 were phototype III, 3 were phototype II and one was phototype IV. Nine out of 14 had received PUVAtherapy alone and 5 PUVAtherapy and broad spectrum UVB. The number of sessions of PUVA received in all the cases was more than 200 (220 to 780), corresponding to a total dose of UVA comprised between 1460 and 3882 Joules. The delay before onset of the tumors varied from 6 to 27 years after the first PUVAtherapy. The mean age at the time of the first irradiation was of 50.2 years (14-75 years). The mean duration of phototherapy was of 10 years (2.23 years).

The increased risk of skin cancer is persistent after discontinuation of psoralen+ultraviolet A: a cohort study

Psoralen+ultraviolet A-treated psoriasis patients are at increased risk for nonmelanoma skin cancer. To assess the persistence of cancer risk among patients who have discontinued psoralen+ultraviolet A and the risk of a first tumor with the passage of time, we prospectively studied the incidence in a cohort of 1,380 psoriasis patients treated with psoralen+ultraviolet A. We observed a total of 27,840 person-years of which 59.4% were considered years without psoralen+ultraviolet. No significant decrease in risk was noted during the first 15 years after psoralen+ultraviolet A was discontinued. Subsequently, the risk of squamous cell carcinoma was reduced (incidence rate ratio=0.79; 95%CI=0.62, 1.01 on treatment vs >15 years off). After 25 years, about 7% of patients with < or =200 psoralen+ultraviolet A treatments and more than half of the patients with > or =400 treatments develop at least one squamous cell carcinoma. After 25 years, almost one third of the patients exposed to > or =200 treatments developed at least one basal cell carcinoma. In conclusion, substantial exposure to psoralen+ultraviolet A dramatically increases the risk of nonmelanoma skin cancer and prior exposure to psoralen+ultraviolet A remains an important issue in the management of patients because the cancer risk associated with psoralen+ultraviolet A is persistent.

Incidence and risk factors associated with a second squamous cell carcinoma or basal cell carcinoma in psoralen + ultraviolet a light-treated psoriasis patients

Psoralen + ultraviolet A-treated psoriasis patients are at increased risk for squamous cell carcinomas and basal cell carcinomas; however, the incidence and risk factors associated with second squamous cell carcinomas and basal cell carcinomas in this population are not well qualified. Incidence and risk factors for second squamous cell carcinomas and basal cell carcinomas were studied in a cohort of 1380 psoralen + ultraviolet A-treated psoriasis patients prospectively followed for over 20 y; 264 had a squamous cell carcinoma and 258 a basal cell carcinoma after beginning psoralen + ultraviolet A therapy. After a first squamous cell carcinoma, the risk of a second squamous cell carcinoma was 26% at 1 y, 62% at 5 y, and 75% at 10 y. Risk increased with high psoralen + ultraviolet A exposure prior to the first squamous cell carcinoma (hazard ratio 3.32, 95% confidence interval 1.53, 7.18). Higher rates of post-first squamous cell carcinoma psoralen + ultraviolet A treatment also were associated with greater risk (hazard ratio 1.56 for every additional 10 treatments per year for patients with low pre-first squamous cell carcinoma psoralen + ultraviolet A exposure, 95% confidence interval 1.35, 1.81). Patients exposed to high levels of tar and/or ultraviolet B before a first squamous cell carcinoma were also at higher risk (hazard ratio 1.72, 95% confidence interval 1.14-2.60). Risk of a second basal cell carcinoma was 21% at 1 y, 49% at 5 y, and 61% at 10 y. There was some evidence that high exposure to psoralen + ultraviolet A before a first basal cell carcinoma was associated with increased risk of second basal cell carcinoma (hazard ratio 1.45, 95% confidence interval 0.97-2.17). Higher post-first tumor psoralen + ultraviolet A treatment rates also increased risk (hazard ratio 1.24 for every additional 10 treatments per year, 95% confidence interval 1.06-1.47). Psoralen + ultraviolet A-treated psoriasis patients appear to have a greatly increased incidence of second squamous cell carcinoma compared with the general population. Patients who develop a squamous cell carcinoma after starting psoralen + ultraviolet A therapy should be closely monitored for a subsequent squamous cell carcinoma.

Cancer risk in a population-based cohort of patients hospitalized for psoriasis in Sweden

Studies of clinical series of psoriasis patients have suggested an increased risk of nonmelanoma skin cancer and melanoma; the risk of other neoplasms has rarely been studied. In order to assess the incidence of cancer in a nationwide series of psoriasis patients from Sweden, we followed up, for the years 1965-89, 9773 patients with a hospital discharge diagnosis of psoriasis made during 1965-83, who were alive and free from malignancy 1 y after first discharge. We compared their incidence of neoplasms with that of the national population by computing standardized incidence ratios (SIR). We observed a total of 789 neoplasms [SIR 1.37, 95% confidence interval (CI) 1.28, 1.47]. There was an increase in the risk of cancers of the oral cavity and pharynx (SIR 2.80, 95% CI 1.96, 3.87), liver (SIR 1.91, 95% CI 1.28, 2.74), pancreas (SIR 1.56, 95% CI 1.02, 2.23), lung (SIR 2.13, 95% CI 1.71, 2.61), skin (squamous cell carcinoma, SIR 2.46, 95% CI 1.82, 3.27), female breast (SIR 1.27, 95% CI 1.00, 1.58), vulva (SIR 3.24, 95% CI 1.18, 7.06), penis (SIR 4.66, 95% CI 1.50, 10.9), bladder (SIR 1.43, 95% CI 1.03, 1.92), and kidney (SIR 1.56, 95% CI 1.04, 2.25). The risk of malignant melanoma was decreased (SIR 0.32, 95% CI 0.10, 0.74). Despite some limitations (possible diagnostic misclassification, lack of data on treatment, relatively short follow-up), our study provides evidence against an increased risk of melanoma among patients hospitalized for psoriasis. In addition to nonmelanoma skin and genital cancers, patients hospitalized for psoriasis were at increased risk of several malignancies, in particular those associated with alcohol drinking and tobacco smoking.

Consensus conference: acitretin in combination with UVB or PUVA in the treatment of psoriasis

Although adjunctive treatment with retinoids in concert with either psoralen-ultraviolet A (PUVA) or ultraviolet B (UVB) phototherapy has been a treatment option for chronic, moderate to severe plaque psoriasis for nearly two decades, acitretin-UV therapy is an underutilized therapeutic modality. According to a recent member survey by the National Psoriasis Foundation, many psoriasis patients are frustrated with available treatment options, which they perceive as ineffective, inconvenient, and/or excessively conservative. Treatment of psoriasis with acitretin in concert with UVB or PUVA is emerging as a viable clinical strategy. Compared with either acitretin or UV light monotherapy alone, the combination regimen enhances efficacy and limits treatment frequency, duration, and cumulative doses. These effects translate into care that is more effective, better tolerated, more convenient, less costly, and, perhaps, safer during long-term treatment than phototherapy alone. Drawing from an extensive literature search and the expertise of its participants, this consensus conference advances clinical recommendations as well as "clinical pearls" for health providers who treat patients with chronic, moderate to severe plaque psoriasis and suggests avenues for future research.

Squamous-cell cancer of the skin in patients given PUVA and ciclosporin: nested cohort crossover study

BACKGROUND

Immunosuppressive treatments have been associated with an increased risk of skin cancer, especially in patients who have had organ transplants. We aimed to assess the risk of skin cancer in patients taking the ciclosporin who had been exposed to psoralen and ultraviolet-A light (PUVA) and other treatments for severe psoriasis.

METHODS

We did a nested cohort crossover study of 28 participants in the PUVA follow-up study who were on ciclosporin to compare the frequency of squamous-cell carcinoma before and after first use of ciclosporin. We also analysed the entire PUVA study cohort (1380) to assess the relation between use of this drug and frequency of squamous-cell carcinoma.

FINDINGS

In the 5 years before first use, six of 28 (21%) ciclosporin users developed a total of 20 squamous cell cancers. After ciclosporin use (average follow-up 6 years), 13 (46%) developed a total of 169 squamous-cell carcinomas. In the nested cohort, after adjustment for amount of exposure to PUVA and methotrexate, incidence of tumours was seven times higher after first ciclosporin use than in the previous 5 years (incidence rate ratio 6.9 [95% CI 4.3-11]). Multivariate analysis of the entire cohort showed that risk of squamous-cell carcinoma after any use of ciclosporin is close to that recorded for at least 200 PUVA treatments (3.1 [2.6-3.7] and 2.8 [2.6-3.2], respectively).

INTERPRETATION

The risk of squamous cell cancer of the skin is increased by ciclosporin in patients with psoriasis who have been exposed to PUVA. Such risks should be balanced against the effectiveness of the drug and possible newer immunosuppressive agents.

Phototherapy for psoriasis

This review covers the current practice of phototherapy with ultraviolet (UV) radiation without sensitizers and of psoralen photochemotherapy (PUVA) in the treatment of psoriasis. Both treatment modalities are well established in today's therapeutic armamentarium. Phototherapeutic regimens use repeated controlled UV exposures to alter cutaneous biology, aiming to induce remission of skin disease. Although UVB has been used for a longer time than PUVA, the latter has been evaluated and validated in a more detailed and coordinated fashion.

Creation of psoriatic plaques: the ultimate tumor suppressor pathway. A new model for an ancient T-cell-mediated skin disease. Viewpoint

From an oncological and immunological perspective, the T-cell-mediated induction of psoriatic plaques should be prone to malignant transformation as the phenotype of psoriatic plaques includes: chronic inflammation, epidermal hyperplasia, prolonged survival and elevated telomerase levels in lesional keratinocytes, as well as angiogenesis, exposure to carcinogens and immunosuppressants. However, conversion of a psoriatic plaque to squamous cell carcinoma is exceedingly rare. This paper explores the possible molecular mechanism for the tumor suppressor pathway in psoriatic lesions, with an emphasis on a putative senescence-switch involving p16.

Induction and excretion of ultraviolet-induced 8-oxo-2'-deoxyguanosine and thymine dimers in vivo: implications for PUVA

Molecular epidemiology has linked ultraviolet-induced DNA damage with mutagenesis and skin carcinogenesis. Ultraviolet radiation may damage DNA in one of two ways: either directly, leading to lesions such as cyclobutane thymine dimers (T<>T), or indirectly, via photosensitizers that generate free radical species that may ultimately produce such oxidative lesions as 8-oxo-2'-deoxyguanosine. We report the results of a pilot, case control study in which seven, healthy, human volunteers (skin type II; aged 23-56 y; three male, four female) received a suberythemal dose of whole body irradiation from ultraviolet-A-emitting fluorescent tubes used in psoralen plus ultraviolet A therapy. First void, mid-stream urine samples were collected pre-exposure and daily postexposure, for up to 13 d. Analysis of urinary 8-oxo-2'-deoxyguanosine and cyclobutane thymine dimers was by competitive enzyme-linked immunosorbent assay (interassay coefficient of variation < or = 10%) and compared with a matched, control group of unirradiated individuals. A maximal increase in levels of urinary 8-oxo-2'-deoxyguanosine was seen 4 d post-ultraviolet exposure. A subsequent reduction was noted, before finally returning to baseline. Similarly, cyclobutane thymine dimer levels peaked 3 d postexposure, before returning to baseline. In contrast to the 8-oxo-2'-deoxyguanosine analysis, however, a second peak was noted at days 9-11, before again returning to baseline. This is the first report examining urinary 8-oxo-2'-deoxyguanosine and cyclobutane thymine dimers following ultraviolet exposure of healthy human subjects. This work illustrates the induction and time course for excretion of ultraviolet-induced lesions, perhaps alluding to repair and ultimately offering the potential to define psoralen plus ultraviolet A dosage regimes in terms of minimizing DNA damage and hence cancer risk.

Increased risk of secondary cancers in patients with primary cutaneous T cell lymphoma

As putative etiologic factors of primary cutaneous T cell lymphomas may have a general cancerogenic effect, we wanted to assess the risk of secondary malignancies in 319 patients diagnosed with histopathologically verified cutaneous T cell lymphomas and reported to the Finnish Cancer Registry during the years 1953-95. Standardized incidence ratios were defined as the ratio of observed to expected numbers of cases. To obtain the expected numbers of cancer, age-, sex-, and period-specific Finnish incidence rates were applied to the appropriate person-years under observation. Ninety-five percent confidence intervals were calculated assuming a Poisson distribution. For the whole period, we detected 36 secondary cancers whereas 26 were expected (standardized incidence ratios 1.4, 95% confidence intervals 1.0-1.9). The overall risk of lung cancer was significantly increased (standardized incidence ratio was 2.7, 95% confidence intervals were 1.4-4.8); and in particular small-cell lung cancer showed high standardized incidence ratios (standardized incidence ratio was 8.5, 95% confidence intervals were 2.8-20). Also, the risk of lymphomas was elevated (standardized incidence ratios for Hodgkin and non-Hodgkin lymphomas combined were 7.0, 95% confidence intervals were 1.9-18). The incidence of other cancers was similar to the national ratios. An increased risk of secondary cancers and in particular small-cell cancer of the lung and lymphomas among patients with primary cutaneous T cell lymphoma is demonstrated. In clinical practice, lung cancer and lymphomas must be kept in mind when following up patients with cutaneous T cell lymphomas.

Basosquamous carcinoma after ultraviolet therapy with artificial sunlight

We report a 63-year-old Japanese man with basosquamous carcinoma developing after ultraviolet therapy with artificial sunlight. Because he had had an eczematous lesion on the right leg five years previously, he had received ultraviolet therapy with artificial sunlight from a mercury-quartz lamp for a total of 30 sessions over a 3-year period. Physical examination revealed an irregular erythematous plaque measuring 5 x 6 cm, with slight eruptions and erosions, on the right leg. A brownish plaque, measuring 9 x 12 cm, surrounded the erythematous plaque. Histopathologically, in the nests of atypical cells in the dermis, nuclear palisading was present at the edge of each tumor cluster. Adjacent clusters exhibited transitions to squamous cells and contained horn pearls. Most of the cells of the epidermis and adnexa were atypical, but cells of the normal adnexal epithelium extended over the atypical cells of the epidermis in an umbrella-like fashion in other lesions. We believe that, in the present case, artificial sunlight therapy caused solar keratosis and that this developed into basosquamous carcinoma. To our knowledge, skin cancer developing after ultraviolet therapy with artificial sunlight without PUVA has not previously been reported in the English literature.

PUVA and cancer risk: the Swedish follow-up study

There is concern about the long-term carcinogenic effects of psoralen and ultraviolet A radiation (PUVA) for treatment of skin disorders. Many authors have found an increased risk for cutaneous squamous cell carcinoma (SCC). Except in anecdotal reports, malignant melanoma had not been observed in patients treated with PUVA until recently. In the U.S.A., a 16-centre prospective study of 1380 patients showed for the first time that there might also be an increased risk for malignant melanoma in patients treated with high cumulative dosages of PUVA. We have therefore followed up the Swedish PUVA cohort until 1994. This cohort had previously been followed up until 1985. Information from 4799 Swedish patients (2343 men, 2456 women) who had received PUVA between 1974 and 1985 was linked to the compulsory Swedish Cancer Registry in order to identify individuals with cancer. The average follow-up period was 15.9 years for men and 16.2 for women. We did not find any increased risk for malignant melanoma in our total cohort of 4799 patients treated with PUVA or in a subcohort comprising 1867 patients followed for 15-21 years. For cutaneous SCC there was an increase in the risk: the relative risk was 5.6 (95% confidence interval, CI 4. 4-7.1) for men and 3.6 (95% CI 2.1-5.8) for women. Significant (P < 0.05) increases were also found in the incidence of respiratory cancer in men and women and of kidney cancer in women. In conclusion, we did not find any increased risk for malignant melanoma in our patients treated with high doses of PUVA and followed up for a long time. We confirm previous reports of an increase in the incidence of cutaneous SCC in patients treated with PUVA, and recommend that patients should be carefully selected for PUVA and rigorously followed up.

PUVA therapy: current concerns in Japan

Photochemotherapy using methoxsalen in combination with long-wave ultraviolet light (PUVA) is an essential modality in the treatment of various skin diseases. Major therapeutic regimens include oral, topical and water-delivery methods. An adequate regimen should be chosen regarding cases of disease, extent of involvement and the age of patients. In Japan, however, treatment techniques and protocols have not yet been standardized. PUVA therapy may be a first choice in the early stages of mycosis fungoides and a second choice or an adjunctive measure in other diseases, such as psoriasis, vitiligo and atopic dermatitis, which have been disabling or resistant to conventional treatments. Japanese guidelines for PUVA therapy of psoriasis are being prepared to be produced. Risks and benefits must be weighed and the patient orientation is necessary to complete the treatment and also to minimize side-effects. Although possible risks for skin cancers in Japanese patients have been reported to be much lower, a careful monitoring of the patient's skin changes is recommended. While action mechanisms are not completely understood, recent investigations suggest that both antiproliferative and immunomodulatory effects are involved. This review article deals with the recent progress in clinical and basic research on PUVA therapy, focusing on our current concerns.

The benefits and risks of long-term PUVA photochemotherapy

In 1974 a new photobiologic principle i.e. light + drug, called photochemotherapy was discovered in Boston and immediately confirmed in Vienna. Psoralen + UVA (PUVA) photochemotherapy has now been applied to the treatment of more than 24 heterogeneous groups of diseases, especially psoriasis and mycosis fungoides. After 24 years of experience in thousands of patients with psoriasis and 23 other skin disorders, virtually the only risk is the development of squamous-cell carcinomas. This risk is low with two exceptions: previous history of treatment with ionizing radiation or inorganic trivalent arsenic, and patients with recalcitrant psoriasis who require continuous treatment for many years. In a recent report from a large USA clinical trial, melanoma developed in a few patients with psoriasis treated with PUVA. This prospective clinical trial did not have a control population, and therefore, the conclusion that PUVA can cause melanoma is tentative.

p53 mutation in squamous cell carcinomas from psoriasis patients treated with psoralen + UVA (PUVA)

Individuals suffering from psoriasis are treated with a combination of psoralen and UVA radiation, commonly referred to as "PUVA" therapy. Epidemiologic studies have shown that PUVA therapy is a risk factor for skin cancer in psoriasis patients. Although PUVA treatment induces skin cancer in laboratory animals, it is unknown whether the increased incidence of skin cancer reported in PUVA-treated psoriasis patients is due to the carcinogenic effects of PUVA or due to other factors such as UVB. Because UV and PUVA induce different types of DNA damage resulting in unique types of p53 mutation, we investigated whether skin cancers from PUVA-treated psoriasis patients have PUVA-type or UV-type p53 mutations. Analysis of 17 squamous cell carcinomas (SCCs) from Austrian PUVA-treated patients revealed a total of 25 p53 mutations in 11 SCCs. A majority of p53 mutations occurred at 5'TpG sites. Although previous studies have shown that 5'TpA sites are the primary targets for PUVA mutagenesis, substitutions at 5'TpG sites are also quite common. Interestingly, a sizable portion of p53 mutations detected were C-->T or CC-->TT transitions, characteristic of UV-induced mutations. Because some psoriasis patients had substantial exposure to UVB before PUVA therapy and because the light sources used in PUVA therapy contained small but significant wavelengths in the UVB region, it is possible that the C-->T and CC-->TT transitions detected in SCCs from PUVA-treated patients were induced by UVB. Nonetheless, our results indicate that both PUVA and UVB may play a role in the development of skin cancer in Austrian psoriasis patients who undergo PUVA therapy.

Malignant melanoma in patients treated for psoriasis with methoxsalen (psoralen) and ultraviolet A radiation (PUVA). The PUVA Follow-Up Study

BACKGROUND

Photochemotherapy with oral methoxsalen (psoralen) and ultraviolet A radiation (PUVA) is an effective treatment for psoriasis. However, PUVA is mutagenic, increases the risk of squamous-cell skin cancer, and can cause irregular, pigmented skin lesions. We studied the occurrence of melanoma among patients treated with PUVA.

METHODS

We prospectively identified cases of melanoma and documented the extent of exposure to PUVA among 1380 patients with psoriasis who were first treated with PUVA in 1975 or 1976. Using incidence data, we calculated the expected incidence of melanoma in this cohort and compared it with the observed incidence. Using regression models, we assessed the risks of melanoma associated with a long time (> or = 15 years) since the first treatment and with a large number of PUVA treatments (> or = 250).

RESULTS

From 1975 through 1990, we detected four malignant melanomas, about the number expected in the overall population (relative risk, 1.1). From 1991 through 1996, we detected seven malignant melanomas (relative risk, 5.4; 95 percent confidence interval, 2.2 to 11.1). The risk of melanoma was higher in the later period than in the earlier one (incidence-rate ratio, 3.8) and higher among patients who received at least 250 PUVA treatments than among those who received fewer treatments (incidence-rate ratio, 3.1).

CONCLUSIONS

About 15 years after the first treatment with PUVA, the risk of malignant melanoma increases, especially among patients who receive 250 treatments or more.

Skin type distribution and skin disease in Ireland

The Irish are generally considered to have a fair complexion. We surveyed the distribution of skin type in an Irish city population (n = 1000). Skin type prevalence was as follows: type 1: 26%, type 2: 49.6%, type 3: 19.7%, type 4: 4.3%, type 5: 0.3%, type 6: 0.1%. Sunbeds were used by 16% of the population. Malignant melanoma occurred in 1.4% of patients, non-melanoma skin cancer in 6%. The high frequency of sunbed use in a fair skinned population and the high incidence of skin cancer is disturbing and highlights the need for ongoing public health education regarding ultraviolet radiation risks.

Fluoroquinolone antibacterials enhance UVA-induced skin tumors

Fluoroquinolone antibacterials are known to be phototoxic, both in vivo and in vitro. The action spectrum for the phototoxicity of the quinolones lies mainly in the UVA region. During studies of systemic drug phototoxicity, Johnson et al. (Dundee) induced dose-dependent phototoxicity in Swiss albino mice, and severe phototoxic reactions were followed by the development of skin tumors. The present study was designed to compare the ability of several quinolones to produce photobiologic effects following chronic, subphototoxic UVA radiation. To compare the activities of different quinolones (lomefloxacin, fleroxacin, ciprofloxacin, ofloxacin and nalidixic acid), doses that result in similar plasma and skin levels of drug were administered by gavage to slightly pigmented Skh-1 hairless mice for up to 78 weeks. 8-Methoxypsoralen (8-MOP) was used as a positive control, and unirradiated, drug-treated and irradiated and unirradiated drug-free controls were also used. No signs of phototoxicity were seen, except for minimal-to-slight erythema and swelling of the skin in animals of the lomefloxacin-UVA group. Skin tumors (1 mm in diameter or larger) were observed in all the irradiated groups and the incidence was increased in all the groups treated with the test articles. The cumulative tumor prevalence was accelerated, the median latent periods were shortened and tumor onset was significantly enhanced by 8-MOP plus UVA, lomefloxacin plus UVA and fleroxacin plus UVA, as compared with vehicle plus UVA-exposed animals. The majority of skin tumors (with the exception of lomefloxacin and 8-MOP) were benign. The majority of squamous cell carcinomas in the lomefloxacin group were of a histologic type different from those previously reported in UVA-exposed animals. Thus, all the fluoroquinolone antibiotics studied have the capability of enhancing UVA-induced phototumorigenesis, but only lomefloxacin caused the development of cystic squamous cell carcinomas in the majority of treated animals.

Squamous cell carcinoma of the penis

Penile tumors, although not frequent, represent a difficult diagnostic and therapeutic challenge. Of the malignant penile neoplasms, the most frequent is penile carcinoma, which includes squamous cell carcinoma and its well-differentiated variant, verrucous carcinoma. Current concepts about classification, epidemiology, pathogenesis, histopathology, diagnosis, staging, prognosis, and treatment are presented.

Premalignant keratinocytic neoplasms

Premalignant keratinocytic keratoses are common, especially in pale-complected persons in whom they appear most often as an actinic keratosis. Although the actinic keratosis has a very low malignant potential, arsenic, tar, thermal, scar, reactional, and radiation keratoses may be more clinically aggressive. This article discusses these premalignant keratinocytic neoplasms.