Guidelines for management of Bowen's disease. British Association of Dermatologists

Therapeutic options for Bowen's disease

Multiple therapeutic options are available for treatment of Bowen's disease. The choice of therapy depends on clinical circumstance and medical practitioner experience. Newer therapies have more extensive support from the literature, but more established therapies may be preferred because of accessibility, cost and efficacy. An overview of the current therapeutic options for Bowen's disease is presented.

Guidelines on the use of photodynamic therapy for nonmelanoma skin cancer: An international consensus

Topical photodynamic therapy (PDT) is used to treat nonmelanoma skin cancers, such as actinic keratoses, Bowen's disease, and basal cell carcinoma (superficial and nodular). This article presents up-to-date, practical, evidence-based recommendations on the use of topical PDT using 5-aminolevulinic acid or methyl aminolevulinate for the treatment (and prevention) of nonmelanoma skin cancers. A systematic literature review was conducted (using MEDLINE), and recommendations were made on the basis of the quality of evidence for efficacy, safety/tolerability, cosmetic outcome, and patient satisfaction/preference. Topical PDT is highly effective in the treatment of actinic keratoses, Bowen's disease, superficial and thin nodular basal cell carcinomas, with cosmesis typically superior to that achieved with existing standard therapies. PDT may also be a means of preventing certain nonmelanoma skin cancers in immunosuppressed patients.

Guidelines for management of Bowen's disease: 2006 update

This article represents a planned regular updating of the previous British Association of Dermatologists (BAD) guidelines for management of Bowen's disease. They have been prepared for dermatologists on behalf of the BAD. They present evidence-based guidance for treatment, with identification of the strength of evidence available at the time of preparation of the guidelines.

Bowen's disease with invasive adnexal carcinoma: The pluripotential nature of Bowen's disease cells

Bowen's disease rarely exhibits multiple combinations of premalignant and/or malignant skin lesions. Bowen's disease with invasive adnexal carcinoma was originally described by Kao, but is not well recognized by clinicians due to its rarity and lack of specific clinical features of this condition. Herein, we describe three unusual cases of Bowen's disease with invasive adnexal carcinoma. The two distinct neoplastic areas exhibited continuity both clinically and histologically. The plaque lesions possessed clinical features typical of Bowen's disease. In cases 1 and 3, we confirmed the adnexal tumor within tumors of Bowen's disease, the diagnosis of which is eccrine porocarcinoma. The tumor in case 2 was characteristic to trichilemmal carcinoma. Immunohistochemically, the tumor cells of Bowen's disease and the adnexal carcinoma differed in antigenicities. The present cases support a notion that Bowen's disease maintains a pluripotential nature.

Imiquimod 5% cream monotherapy for cutaneous squamous cell carcinoma in situ (Bowen's disease): A randomized, double-blind, placebo-controlled trial

BACKGROUND

We conducted a double-blind, placebo-controlled, randomized trial to evaluate the preliminary efficacy and safety of imiquimod 5% cream treatment for cutaneous squamous cell carcinoma (SCC) in situ.

METHODS

In all, 31 patients with biopsy-proven cutaneous SCC in situ were randomly assigned to placebo (vehicle) (n = 16) or imiquimod 5% cream (n = 15) daily for 16 weeks. Patients were assessed at week 28 for the primary end point, resolution of cutaneous SCC in situ.

RESULTS

Of the 31 patients enrolled, 3 dropped out. Intention-to-treat analysis revealed 11 of the 15 patients (73%) in the imiquimod group achieved resolution of cutaneous SCC in situ, with no relapse during the 9-month follow-up period; none in the placebo group achieved resolution (P < .001). Imiquimod 5% cream was generally well tolerated and there were no serious adverse events.

LIMITATIONS

Topical imiquimod 5% cream has proven to be an effective treatment for cutaneous SCC in situ. However, studies to define the ideal dosing regimen and cost-effectiveness are required before it can be accepted as a recognized therapy.

CONCLUSIONS

In this controlled trial, patients with cutaneous SCC in situ receiving topical imiquimod 5% cream as monotherapy experienced a high degree of clinical benefit compared with placebo.

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.

Investigation of the use of the pulsed dye laser in the treatment of Bowen's disease using 5-aminolaevulinic acid phototherapy

BACKGROUND

The use of 5-aminolaevulinic acid photodynamic therapy (ALA-PDT) for the treatment of Bowen's disease is well established. However, treatment with a continuous light source has the disadvantage of prolonged treatment time during which patients often experience significant discomfort requiring the use of local anaesthetic.

OBJECTIVES

The aim of this study was to assess the efficacy and safety of the pulsed dye laser (PDL) as the light source for photoactivation of the protoporphyrin IX to treat Bowen's disease by PDT.

METHODS

Thirteen patients with a total of 17 patches of histologically proven Bowen's disease were treated with 20% 5-ALA in Unguentum M (Crookes Healthcare, Nottingham, U.K.) under occlusion for 4 h. The patches were then irradiated using a Candela SPLTL-1b (Candela Corporation, Wayland, MA, U.S.A.) PDL using a wavelength of 585 nm, with a 7-mm diameter spot at a fluence of 10 J cm(-2). The spots overlapped by 50% to cover the lesion and extend beyond the clinical margin of the patch of Bowen's disease by 0.5 cm. Patients were then followed up initially at 2 months, then at 3-monthly intervals for a period of 12 months to assess treatment success and recurrence rate.

RESULTS

Subjects consisted of 10 females and three males, between 47 and 88 years. The mean area of the patches of Bowen's disease was 315.4 mm(2) (range 36-2464 mm(2)) requiring a median of 32 pulses (range 3-260). Lesions sites were hands (two), foot (one) and lower leg (14). All patients experienced varying degrees of discomfort during treatment but none required the use of local anaesthetic. At 2 months eight treatment sites could not be assessed due to loose overlying crusts and removal of these revealed superficial erosions in seven patients. Of the 17 lesions treated, on follow-up at 1 year, 14 patches (82%) demonstrated a complete clinical response, although one of these had required a second treatment. Two patients with three lesions that would have required further therapy refused a second treatment. Prolonged crusting lasting 8 weeks occurred in eight patches and prolonged discomfort lasting 6 weeks occurred in four patients.

CONCLUSIONS

This study has shown that the PDL is an effective light source for ALA-PDT of Bowen's disease. Light source exposure times are shorter, although overall treatment time may not always be significantly reduced for larger lesions. The procedure was well tolerated. However, the post-treatment morbidity was relatively high compared with the more conventional treatment modalities. Further studies are needed to determine whether lower energy fluences can maintain similar efficacy while reducing post-treatment morbidity.

Radiation therapy for Bowen’s disease of the skin

PURPOSE

To assess the clinical outcome in the radiation therapy (RT) of squamous carcinoma in situ of the skin (Bowen's disease). We focused on the local control rate and the toxicity according to the biologically effective dose (BED).

METHODS AND MATERIALS

A retrospective review was performed on 44 patients with Bowen's disease treated at Princess Margaret Hospital from April 1985 to November 2000. RT was the primary treatment for 32 patients, whereas 12 received RT for residual disease after local ablative therapy. Lesions were located as follows: scalp, 9 patients (20%); face, 12 (27%); trunk, 6 (14%), extremity, 12 (27%), perianal, 3 (7%), and penis, 2 (5%). Orthovoltage X-rays were used in the majority (39 of 44, 89%). There was no standard fractionation regimen: some physicians prescribed high doses, as for invasive skin cancer, whereas others prescribed lower doses because of the noninvasive nature of the disease, a sensitive anatomic location (e.g., extremity), or large treatment area. Because of the variations in fractionation regimens, BED was used as a common metric for biologic effect in the comparison of different regimens and analyzed for correlation with recurrence and toxicity. Local control was defined as the lack of persistent or recurrent disease at the treated site for the follow-up period. Grade 4 toxicity was defined as necrosis (cartilage/bone damage) and/or ulceration for a duration of >3 months.

RESULTS

The mean patient age was 67.7 years, and the male/female ratio was 29:15. The median pretreatment lesion size was 2.65 cm(2) (range, 0.07-34.56 cm(2)). Complete remission was achieved in 42 patients, with follow-up unavailable for the remaining 2 patients. Subsequently, 3 patients experienced recurrences at 0.2, 1.1, and 1-1.5 years after complete remission. One recurrence was Bowen's disease (local); the others were squamous cell carcinoma (one local, one marginal). Four patients experienced a new squamous lesion at a distant cutaneous site. As of last follow-up, 32 patients (73%) were known to be alive. Median follow-up was 2.6 years (range, 0-11.8 years). All but 3 patients were disease-free at last follow-up, 1 of whom died with distant, but not local disease. The 5-year overall survival rate was 68%. Biologically effective dose was not associated with recurrence. The crude local control rate was 93%. There was a trend toward higher radiation doses for smaller pretreatment tumor and field sizes. The BED did not correlate with Grade 4 toxicity; however, the three cases of Grade 4 toxicity occurred in patients treated with hypofractionated regimens (dose per fraction >4 Gy) for extremity lesions.

CONCLUSIONS

Radiation therapy is an effective treatment option for Bowen's disease of the skin. Local recurrences seem to be equally low in patients treated with high- and low-dose regimens. Avoiding hypofractionated regimens (dose per fraction >4 Gy) in extremity locations might reduce the risk of Grade 4 toxicity.

Enfermedad de Bowen perianal tratada con imiquimod

Bowen's disease is a special form of squamous cell carcinoma in situ that usually develops in photoexposed areas of skin. The treatment of choice is surgery. Less frequently, it may appear in other locations such as the nails, glans penis, intertriginous areas and the perianal region, where conventional treatment may be complicated. We contribute a new case of perianal Bowen's disease, which responded to treatment with imiquimod with no evidence of clinical recurrence after 3 years of follow up. Imiquimod appears to be a therapeutic alternative for perianal Bowen's disease, which seems to have a particular tendency to recur in this location where surgery may also be complicated.

Evidence-based practice of photopheresis 1987-2001: a report of a workshop of the British Photodermatology Group and the U.K. Skin Lymphoma Group

Photopheresis or extracorporeal photochemotherapy (ECP) is a novel immunomodulatory therapy which involves separation of the patient's leucocyte-rich plasma, followed by ex vivo administration of a photosensitizer and ultraviolet A radiation, before reinfusion. ECP has been used successfully for the treatment of cutaneous T-cell lymphoma (CTCL: Sézary syndrome), graft-versus-host disease (GVHD) and cardiac transplant rejection. ECP has a dose-sparing effect on concurrent immunosuppressive therapy. The procedure induces apoptosis of the irradiated lymphocytes, but the exact mechanism by which ECP exerts its therapeutic effect in these different conditions is uncertain. The treatment has very few adverse effects and in particular is not associated with an increased incidence of opportunistic infections. The evidence for the efficacy of ECP has been appraised by a combined British Photodermatology Group and U.K. Skin Lymphoma Group workshop on the basis of evidence published up to the end of 2001 and on the consensus of best practice. There is fair evidence for the use of ECP in erythrodermic CTCL and steroid-refractory GVHD, but randomized controlled studies are needed. There is good evidence supporting the use of ECP in preventing cardiac rejection following transplantation. Randomized controlled trials have also shown a therapeutic benefit in type 1 diabetes mellitus, but the inconvenience associated with the procedure outweighed the clinical benefit. There is fair evidence not to use ECP for the treatment of systemic sclerosis and multiple sclerosis, and good evidence not to use ECP for other forms of CTCL.

Cutaneous squamous carcinoma in situ (Bowen's disease): Treatment with Mohs micrographic surgery

BACKGROUND

Bowen's disease (BD), also known as squamous intraepidermal carcinoma, is a malignant skin tumor with a potential to progress to invasive carcinoma.

OBJECTIVE

We sought to report a large series of patients with BD treated with Mohs micrographic surgery (MMS).

METHODS

This prospective, multicenter, case series included all patients in Australia treated with MMS for BD, who were monitored by the Skin and Cancer Foundation between 1993 and 2002.

RESULTS

There were 270 cases; the majority (93.4%) were located in the head and neck area. In 50.7% of cases it was a recurrent tumor. In 20% the tumor was initially misdiagnosed as basal cell carcinoma or squamous cell carcinoma. No cases with perineural invasion were diagnosed. There were 6 cases of recurrence (6.3%) of 95 patients who completed a 5-year follow-up period after MMS.

CONCLUSION

The low 5-year recurrence rate of BD with MMS emphasizes the importance of margin-controlled excision, especially in the head and neck area where tissue preservation is essential.

Therapieoptionen bei epithelialen Hauttumoren

There has been worldwide a significant rise in the incidence of epithelial skin tumors and their precursors in the past years with an increased number of younger patients affected. The risk factors are identified. The choice of the appropriate treatment for each individual is crucial. Major consideration include high cure rate, low long-term recurrence rate and few side effects. In the following article different therapeutic approaches for actinic keratoses, Bowen's disease, basal cell carcinoma and squamous cell carcinoma are presented and analysed.

Photodynamic therapy using a novel photosensitizer, ATX-S10(Na): comparative effect with 5-aminolevulinic acid on squamous cell carcinoma cell line, SCC15, ultraviolet B-induced skin tumor, and phorbol ester-induced hyperproliferative skin

Photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA) is available for the treatment of actinic keratosis (AK). Recently, we developed a new PDT photosensitizer, ATX-S10(Na), and have shown that ATX-S10(Na) PDT is effective for the treatment of various human skin diseases, such as squamous cell carcinoma, Bowen's disease, basal cell carcinoma, and psoriasis. In the present study, we compared the effects of ATX-S10(Na) PDT and ALA PDT on hyperproliferative skin induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), on the squamous cell carcinoma cell line, SCC15, in vitro, and on UVB-induced skin tumors in vivo. TPA treatment induced epidermal acanthosis, which was more markedly suppressed by ATX-S10(Na) PDT than by ALA PDT. ATX-S10(Na) PDT more effectively eliminated UVB-induced AK and squamous cell carcinoma (SCC) than ALA PDT. Furthermore, both ATX-S10(Na) PDT and ALA PDT induced the death of SCC15 cells, and the effect of ATX-S10(Na) PDT was greater than that of ALA PDT. Our results indicate that ATX-S10(Na) PDT might be more effective than ALA PDT for the treatment of various skin diseases.

Bowen's disease of the nipple—a new method of treatment

Squamous cell carcinoma in situ (Bowen's disease) is a common skin condition but has only rarely been described on the nipple. All reported cases have been treated with wide local excision and observation. A new treatment for Bowen's disease is photodynamic therapy. This has been reported as being able to treat Bowen's disease in other sites effectively with an acceptable local recurrence rate. We describe two patients presenting with itching and scaling of the nipple which were histologically proven Bowen's disease, one of these patients was treated successfully with a combination of photodynamic therapy and cryotherapy: this is the first time such a lesion has been treated in this way.

Tratamiento tópico con Imiquimod crema al 5% de la enfermedad de Bowen del pene

We present an alternative treatment of the intraepithelial neoplasms of penis (Bowen's disease), the topical application of imiquimod 5% cream. It was applied 3 times weekly for 5 weeks. Imiquimod is an imidazoquinolone immune response modifier that has been shown to have indirect antiviral and antitumor effects with few adverse effects. Imiquimod 5% cream may represent an alternative treatment option for Bowen's disease.

Dermoscopy of Bowen's disease

BACKGROUND

Dermoscopy improves the diagnostic accuracy in pigmented skin lesions, but it is also useful in the evaluation of nonpigmented skin tumours as it allows the recognition of vascular structures that are not visible to the naked eye. Bowen's disease (BD) or squamous cell carcinoma in situ is usually nonpigmented, but may also rarely be pigmented. Objective To describe the dermoscopic features in a series of pigmented and nonpigmented BD.

METHODS

Dermoscopic images of 21 histopathologically proven BD were evaluated for the presence of various dermoscopic features. Each lesion was photographed using the Dermaphot (Heine Optotechnik, Herrsching, Germany), at 10-fold magnification, and the colour slides were scanned to digital format using a Kodak Photo CD system.

RESULTS

The majority of cases of BD revealed a peculiar dermoscopic pattern characterized by glomerular vessels (90%) and a scaly surface (90%). In addition, in pigmented BD small brown globules regularly packed in a patchy distribution (90%), and structureless grey to brown pigmentation (80%) were observed.

CONCLUSIONS

Dermoscopy can be helpful for diagnosing BD because of the presence of repetitive morphological findings such as glomerular vessels and a scaly surface. In pigmented BD, small brown globules and/or homogeneous pigmentation can be seen as well.

Erbium:YAG Laser Pretreatment Accelerates the Response of Bowen's Disease Treated by Topical 5-Fluorouracil

BACKGROUND

Topical 5-fluorouracil (5-FU) is a standard treatment for Bowen's disease. However, its efficacy may be limited by the presence of stratum corneum. The Er:YAG laser has shown a dramatic enhancement effect on the delivery of 5-FU in vitro by ablation of the stratum corneum. The efficacy of laser-assisted delivery of 5-FU has not been tested in human.

OBJECTIVE

To see whether Er:YAG laser pretreatment can improve the efficacy of topical 5-FU in the treatment of Bowen's disease.

METHODS

Three target lesions from a patient with multiple Bowen's disease were selected for a half-side comparison study. The Er:YAG laser was used to remove the cornified layer on one side of each lesion, followed by twice-daily application of 5-FU cream to both sides. Clinical and histologic responses were compared.

RESULTS

Lesions pretreated with the Er:YAG laser showed more rapid clinical and histologic responses to topical 5-FU than those treated with 5-FU alone. Evaluation at 9 months after treatment showed no recurrences of lesions on both sides.

CONCLUSIONS

Our preliminary study demonstrates that this Er:YAG laser-assisted modality is effective and shows accelerated clinical response and shortened treatment time compared with topical 5-FU as a single treatment.

Squamous cell carcinoma in situ of the skin: History, presentation, biology and treatment

Squamous cell carcinoma in situ (SCCIS) of the skin is a problem commonly dealt with by dermatologists. The classic presentation, originally described by Bowen, is easily recognized, but presentation on some anatomical surfaces may be associated with less than typical features. Major aetiological factors for this disease are UV light, human papillomavirus infection and immunosuppression. The natural course of SCCIS is usually prolonged, with treatment being appropriate, but not urgent. The choice of therapy requires consideration of the location of the lesion, and a desire for a high cure rate without causing loss of form, function or cosmesis. The immunomodulatory agent imiquimod has offered a significant advance for the topical treatment of SCCIS. Our improved understanding of the underlying biology of SCCIS permits us to make rational choices of treatment. In the future we may be able to determine which of these lesions may progress to invasive disease, and help us select the most effective therapy.

Treatment of squamous cell carcinoma with intralesional 5-Fluorouracil

BACKGROUND

5-Fluorouracil (5-FU) has been used topically and intralesionally to treat lesions related to squamous cell carcinoma (SCC) such as actinic keratosis, Bowen's disease, and keratoacanthoma.

OBJECTIVE

We sought to determine whether intralesional 5-FU might be effective in treating a patient with SCC.

METHODS

A patient with SCC at the junction of the right alar crease and right nasolabial fold was treated with eight weekly injections of 5-FU, with doses ranging from 0.8 to 2.4 mL.

RESULTS

A repeat biopsy after the eighth treatment showed total clearance of the cancer, and the patient has remained free of recurrence during a 5-month follow-up period.

CONCLUSION

This modality may provide patients with SCC in cosmetically important locations or in areas that require complex surgery the advantage of a nonsurgical cure.

Treatment of Bowen's disease and erythroplasia of Queyrat

Bowen's disease of the skin may have differing clinical presentations depending on the skin surface on which it presents, but has the same histologic features of squamous cell carcinoma in situ wherever it occurs. The etiologic factors include ultraviolet light and human papillomavirus infection. The choice of therapy requires a consideration for retention of form, function and cosmosis while offering a high cure rate. The immunodualtory agent imiquimod has been shown to be an effective treatment on a variety of skin surfaces.

Treatment of large facial Bowen's disease: case report

Bowen's disease (BD; squamous cell carcinoma in situ) is a common, persistent condition that can be related to chronic sun damage, and consequently, is usually located around the head and neck area and lower limbs. Bowen's disease can be treated with a variety of methods, including surgery or laser therapy, but large lesions tend to scar postexcision and hence are difficult to treat surgically. Here we present the case of a 75-year-old woman with a 20-year history of facial BD unabated by treatment with a variety of topical agents and cryotherapy. Application of imiquimod 5% cream on alternate nights for 6 weeks resulted in total clearance with no recurrence observed after 8 months.

Treatment of Bowen's disease of the penis with imiquimod 5% cream

We present a case of persistent and progressive Bowen's disease (squamous cell carcinoma in situ) of the penis, in an otherwise healthy 56-year-old man. Treatment with imiquimod 5% cream was effective when applied once a day for 3 consecutive days followed by 4 days without treatment, over a period of 5 weeks.

Treatment of Bowen's disease using a cycle regimen of imiquimod 5% cream

Bowen's disease (BD; intraepithelial squamous cell carcinoma) is a challenging condition to treat because lesions, which can be multiple, are often located at sites that heal poorly, such as the shin. The disease is usually persistent and progressive and appears as an enlarging, demarcated erythematous plaque. Two elderly female patients with Bowen's disease of the lower leg are presented. Imiquimod 5% cream was applied in a cycle of three times weekly for 3 weeks followed by a 4-week rest period. The treatment was successful after a second cycle of therapy, with both cases clinically clear at 2- and 3-month follow-up visits.

Topical 5-aminolaevulinic acid photodynamic therapy for cutaneous lesions: outcome and comparison of light sources

BACKGROUND

Topical 5-aminolaevulinic acid (ALA) photodynamic therapy (PDT) is increasingly used for superficial non-melanoma skin cancers and their precursors.

METHODS

We report our 3-year experience of topical ALA-PDT, with a preliminary comparison of the effects of broadband and laser light sources.

RESULTS

We performed 688 treatments on 483 lesions in 207 patients. Complete clearance was achieved in 222/239 lesions of Bowen's disease (BD), superficial basal cell carcinoma (sBCC) and actinic keratosis (AK) (93%) - 117/129 BD (91%), 84/87 sBCC (97%) and 21/23 AK (91%), with a median follow up of 48 weeks. Broadband and laser light sources were of similar efficacy. Recurrences have occurred in 10.3% BD, 4.8% sBCC and 4.8% AK. Adverse effects from PDT were uncommon but included pigmentary change (2%) and minor scarring (2%). How-ever, severe pain was experienced in 16-21% of treatments using the high-output broadband and laser sources, but in only 2% with the low-output xenon arc source.

CONCLUSION

Topical ALA-PDT is effective for BD, sBCC and AK and has been an invaluable addition to our dermatology service. Efficacy is similar for broadband and laser light sources, although treatment at higher surface irradiance may be painful, and excellent cosmetic results can be achieved.

Randomized comparison of photodynamic therapy with topical 5-fluorouracil in Bowen's disease

BACKGROUND

Bowen's disease (BD; intraepithelial squamous cell carcinoma) is therapeutically challenging because lesions, which may be multiple, are frequently located at sites that heal poorly. There is a small risk of progression to invasive carcinoma. Photodynamic therapy (PDT) is an effective treatment for certain non melanoma skin cancers, but comparison studies with other, better-established therapies are limited.

OBJECTIVES

To compare the efficacy and tolerability of PDT and topical 5-fluorouracil (5-FU) in BD.

METHODS

Forty patients from two centres were randomized to either topical PDT or 5-FU. The PDT group was treated with 20% 5-aminolaevulinic acid (ALA) applied 4 h before illumination with 100 J cm-2 narrowband red light (630 +/- 15 nm). 5-FU was applied to lesions for 4 weeks. A repeat treatment cycle was performed after 6 weeks if required. Results Twenty-nine of 33 (88%) lesions treated with PDT initially responded completely, compared with 22 of 33 (67%) after 5-FU. After 12 months, two recurrences in the PDT group and six in the 5-FU group reduced complete clinical clearance rates to 82% and 48%, respectively. PDT was significantly more effective (P = 0.006, odds ratio 4.78, 95% confidence interval 1.56-14.62). In the 5-FU group, severe eczematous reactions developed around seven lesions, ulceration in three and erosions in two. No such reactions occurred following PDT. There was no difference in overall pain experienced during each therapy.

CONCLUSIONS

Topical ALA-PDT is more effective than topical 5-FU in the treatment of BD, with fewer adverse events. ALA-PDT should be considered one of the first-line therapeutic options for BD.

The emerging role of 5-ALA-PDT in dermatology: is PDT superior to standard treatments?

Several open studies report the efficacy of topical photodynamic therapy (PDT) in the treatment of non-melanoma skin cancer and pre-cursor lesions. For a new therapy to change clinical practice, comparison studies with standard therapies are required, assessing efficacy, adverse events and cosmetic outcome. This review considers the evidence for using topical PDT over standard therapies in non-melanoma skin cancer. Limited data indicates topical PDT to be superior to cryotherapy and equivalent to topical 5-fluorouracil in clearing non-hyperkeratotic actinic keratoses, and to achieve a superior cosmetic outcome. Topical PDT is superior to topical 5-fluorouracil, and equivalent to cryotherapy, in the treatment of squamous cell carcinoma in situ (Bowen's disease), again with fewer adverse reactions. Similarly, PDT is as effective as cryotherapy for basal cell carcinoma, but with superior healing and cosmesis. PDT may be particularly advantageous for large and/or multiple lesions and for those in sites where disfigurement or poor healing from conventional therapies is a particular risk. There remains a lack of comparison data concerning routine surgery, curettage, and radiotherapy, but topical PDT would appear as effective as, and in certain aspects superior to, standard therapies in the treatment of non-melanoma skin cancer.

Successful treatment of anogenital Bowen's disease with the immunomodulator imiquimod, and monitoring of therapy by DNA image cytometry

Imiquimod (Aldara, 3M) is an immune response modifier used for the treatment of anogenital warts. We report a 55-year-old non-immunocompromised woman with extensive, human papillomavirus (HPV) 16-positive anogenital Bowen's disease. After 5 months of local treatment with imiquimod, the lesions completely regressed clinically and histologically, and HPV 16 DNA was no longer detectable. Moreover, DNA image cytometry revealed DNA aneuploidy (an indicator of prospective malignancy) in pretreatment samples but not in post-treatment samples. Therefore, imiquimod might be a treatment option for Bowen's disease, particularly in patients where other treatment modalities such as surgery are contraindicated.

Guidelines for topical photodynamic therapy: report of a workshop of the British Photodermatology Group

Topical photodynamic therapy (PDT) is effective in the treatment of certain non-melanoma skin cancers and is under evaluation in other dermatoses. Its development has been enhanced by a low rate of adverse events and good cosmesis. 5-Aminolaevulinic acid (ALA) is the main agent used, converted within cells into the photosensitizer protoporphyrin IX, with surface illumination then triggering the photodynamic reaction. Despite the relative simplicity of the technique, accurate dosimetry in PDT is complicated by multiple variables in drug formulation, delivery and duration of application, in addition to light-specific parameters. Several non-coherent and coherent light sources are effective in PDT. Optimal disease-specific irradiance, wavelength and total dose characteristics have yet to be established, and are compounded by difficulties comparing light sources. The carcinogenic risk of ALA-PDT appears to be low. Current evidence indicates topical PDT to be effective in actinic keratoses on the face and scalp, Bowen's disease and superficial basal cell carcinomas (BCCs). PDT may prove advantageous where size, site or number of lesions limits the efficacy and/or acceptability of conventional therapies. Topical ALA-PDT alone is a relatively poor option for both nodular BCCs and squamous cell carcinomas. Experience of the modality in other skin diseases remains limited; areas where there is potential benefit include viral warts, acne, psoriasis and cutaneous T-cell lymphoma. A recent British Photodermatology Group workshop considered published evidence on topical PDT in order to establish guidelines to promote the efficacy and safety of this increasingly practised treatment modality.

Role of lasers and photodynamic therapy in the treatment of cutaneous malignancy

Tumor therapy is not a common indication for the use of lasers, as it is in the treatment of benign vascular skin lesions, since many alternative treatment modalities exist. However, certain patients may benefit from laser therapy of premalignant and malignant skin tumors. Skin tumors can be treated by laser excision, laser coagulation, laser vaporization, or photodynamic therapy (PDT). For these purposes, the carbon dioxide laser, the neodymium:yttrium aluminum garnet laser and the argon laser are particularly suitable. PDT is a therapeutic approach based on the photosensitization of the target tissue by topical or systemic photosensitizers and subsequent irradiation with light from a laser or a lamp inducing cell death via generation of reactive oxygen species. Laser therapy and PDT have shown good results in the curative treatment of actinic keratoses, superficial basal cell carcinoma, Bowen's disease and cheilitis actinica. However, they are not recommended for primary malignant melanoma and invasive squamous cell carcinoma. In some patients, lasers and PDT might also be used effectively for the palliative treatment of cutaneous metastases. In selected patients, lasers and PDT may offer some advantages over routine procedures, e.g. reduction of scarring and better cosmetic results. However, when treating invasive tumors with curative intention, one has to bear in mind the lack of histologic control and the limited depth of tissue penetration of most laser and PDT therapies.

Photodynamic therapy: applications in dermatology

Photodynamic therapy (PDT) offers the potential of an effective new treatment in several areas of medicine. Topical photodynamic therapy is practical and non-invasive and is particularly suited to dermatological indications. A variety of pre-malignant and malignant skin lesions including Bowen's disease, actinic keratoses (AKs) and basal cell carcinoma (BCC) have been treated with success. The role of PDT in inflammatory dermatoses remains to be established. The currently available literature is reviewed.