Treatment of cutaneous Bowen's disease with particular emphasis on the problem of lower leg lesions

Squamous Cell Carcinoma In Situ-The Importance of Early Diagnosis in Bowen Disease, Vulvar Intraepithelial Neoplasia, Penile Intraepithelial Neoplasia, and Erythroplasia of Queyrat

Cutaneous squamous cell carcinoma (cSCC) is the second-most-prevalent malignancy in humans. A delayed diagnosis of cSCC leads to heightened invasiveness and positive surgical margins. Bowen's disease (BD) represents an early form of cSCC and presents as a small erythematous, photo-distributed, psoriasiform plaque. Although certain dermoscopy features in BD are quite characteristic, histopathology remains the gold standard for diagnosis and provides a severity-scoring system that assists in guiding appropriate treatment strategies. The classification of precancerous lesions of the vulva and penis has undergone multifarious transformations due to variations in clinical and histopathological characteristics. Presently, erythroplasia of Queyrat is categorized as a clinical variant of penile intraepithelial neoplasia (PeIN). The diagnoses of vulvar intraepithelial neoplasia (VIN) and PeIN present significant challenges and typically necessitate one or more biopsies, potentially guided by dermoscopy. Aceto-white testing demonstrates a notably high negative predictive value for genital precancerous lesions. Histopathological examination represents the gold-standard diagnosis in VIN and PeIN, while p16 and p53 immunostainings alongside HPV testing provide crucial diagnostic clues. The histopathologic features, degree of differentiation, and associations with lichen planus, lichen sclerosus, and HPV guide the selection of conservative treatments or surgical excision.

Non-melanoma Skin Cancer in Canada Chapter 5: Management of Squamous Cell Carcinoma

Background

Squamous cell carcinoma (SCC) is the second-most common form of non-melanoma skin cancer (NMSC).

Objective

To provide guidance to Canadian health care practitioners regarding management of SCCs.

Methods

Literature searches and development of graded recommendations were carried out as discussed in the accompanying introduction (chapter 1 of the NMSC guidelines).

Results

SCCs are sometimes confined to the epidermis, but they can also invade nearby tissues and, in some cases, metastasize to neighbouring lymph nodes or other organs. This chapter discusses the natural history, staging, prognosis, and management of SCC—a tumour type that is less common but typically more aggressive than BCC. For this reason, margin control is strongly preferred in treating SCCs.

Conclusions

Although approaches such as cryosurgery and radiation therapy may be considered for some patients, surgical excision—sometimes coupled with radiation—remains the cornerstone of SCC management. Patients with high-risk SCC may also be considered for referral to an appropriate multidisciplinary clinic.

Nonsurgical treatment of nonmelanoma skin cancer

The ever-increasing incidence of primary cutaneous malignancies has heralded the need for multiple treatment options. Surgical modalities remain the mainstay of treatment of nonmelanoma skin cancer. However, it is important for the dermatologic surgeon to have an understanding of all treatment options to assist the patient in making the most informed decision possible, ultimately leading to the most favorable outcome. This article explores the available nonsurgical treatment options, their indications, and their efficacy.

Recent advances in the prevention and treatment of skin cancer using photodynamic therapy

Photodynamic therapy (PDT) is a noninvasive procedure that involves a photosensitizing drug and its subsequent activation by light to produce reactive oxygen species that specifically destroy target cells. Recently, PDT has been widely used in treating non-melanoma skin malignancies, the most common cancer in the USA, with superior cosmetic outcomes compared with conventional therapies. The topical 'photosensitizers' commonly used are 5-aminolevulinic acid (ALA) and its esterified derivative methyl 5-aminolevulinate, which are precursors of the endogenous photosensitizer protoporphyrin IX. After treatment with ALA or methyl 5-aminolevulinate, protoporphyrin IX preferentially accumulates in the lesion area of various skin diseases, which allows not only PDT treatment but also fluorescence diagnosis with ALA-induced porphyrins. Susceptible lesions include various forms of non-melanoma skin cancer such as actinic keratosis, basal cell carcinoma and squamous cell carcinoma. The most recent and promising developments in PDT include the discovery of new photosensitizers, the exploitation of new drug delivery systems and the combination of other modalities, which will all contribute to increasing PDT therapeutic efficacy and improving outcome. This article summarizes the main principles of PDT and its current clinical use in the management of non-melanoma skin cancers, as well as recent developments and possible future research directions.

Guidelines for topical photodynamic therapy: update

Multicentre randomized controlled studies now demonstrate high efficacy of topical photodynamic therapy (PDT) for actinic keratoses, Bowen's disease (BD) and superficial basal cell carcinoma (BCC), and efficacy in thin nodular BCC, while confirming the superiority of cosmetic outcome over standard therapies. Long-term follow-up studies are also now available, indicating that PDT has recurrence rates equivalent to other standard therapies in BD and superficial BCC, but with lower sustained efficacy than surgery in nodular BCC. In contrast, current evidence does not support the use of topical PDT for squamous cell carcinoma. PDT can reduce the number of new lesions developing in patients at high risk of skin cancer and may have a role as a preventive therapy. Case reports and small series attest to the potential of PDT in a wide range of inflammatory/infective dermatoses, although recent studies indicate insufficient evidence to support its use in psoriasis. There is an accumulating evidence base for the use of PDT in acne, while detailed study of an optimized protocol is still required. In addition to high-quality treatment site cosmesis, several studies observe improvements in aspects of photoageing. Management of treatment-related pain/discomfort is a challenge in a minority of patients, and the modality is otherwise well tolerated. Long-term studies provide reassurance over the safety of repeated use of PDT.

Methyl aminolevulinate: actinic keratoses and Bowen's disease

Topical photodynamic therapy (PDT) using the methyl ester of 5-aminolaevulinic acid (MAL) is an effective therapy for actinic keratoses and Bowen's disease. Thin and moderate thickness facial actinic keratoses respond best, with clearance rates equivalent or superior (depending on protocol) to current therapy, and with notably superior cosmetic outcome. Patients with areas of field cancerization and organ transplant recipients may particularly benefit from topical MA-PDT. The response rate of Bowen's disease to MAL-PDT is also at least equivalent to cryotherapy and 5-fluorouracil, again with superior cosmesis. Patients with large or multiple lesions of Bowen's disease or those in whom standard therapy, including surgery, is relatively contraindicated may particularly benefit from PDT.

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.

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 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.

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.

Radiation therapy for Bowen's disease: lessons for lesions of the lower extremity

OBJECTIVE

A retrospective outcomes review of radiotherapy for Bowen's disease was performed to analyze all patients treated with radiation therapy between 1993 and 1997 at the Naval Medical Center, San Diego.

METHODS

Eleven patients with 16 lesions were treated with a median time-dose-fractionation value of 105 (range, 93-108).

RESULTS

All 11 patients were without evidence of disease within 1 to 2 months of completing treatment. Four of the 16 lesions (25%) were unhealed at time of last follow-up; the remainder healed with good cosmetic result. All unhealed lesions were on the lower extremity. Median follow-up was 27.5 months (range, 9-57 months).

CONCLUSION

Radiation remains a good therapeutic option in selected patients with Bowen's disease, but caution should be exercised before selection of patients with lesions in potentially poor healing areas, such as the lower extremity.

Comparison of cryotherapy with curettage in the treatment of Bowen's disease: a prospective study

BACKGROUND

In our departments, curettage and cautery (C&C) and liquid nitrogen cryotherapy are the preferred methods of treatment for Bowen's disease (BD).

OBJECTIVES

We aimed to compare these two treatments with regard to efficacy, time to heal, morbidity and recurrence rate.

METHODS

Cryotherapy was performed using a liquid nitrogen spray giving two freeze-thaw cycles, each freeze cycle being maintained for 5-10 s after the formation of an ice ball to the intended margin. Curettage was performed with a conventional disposable curette under local anaesthesia, and electrocautery was then used for haemostasis.

RESULTS

Eighty lesions in 67 patients (55 female) were analysed. The mean age of the patients was 74 years (range 46-89). The most frequent site was the lower leg, below the knee (n = 59, 74%). The average time taken for complete healing after the procedure was 60 days. The mean size of the lesions was 336 mm(2) (range 30-1890). The patients were followed up for a mean of 22 months (range 6-24, median 2 years). In the cryotherapy group (n = 36 lesions), the median time to complete healing was 46 days (range 14-210; mean 69). Twelve lesions took more than 90 days to heal. Infection requiring antibiotics developed in four patients. Thirteen of the treated lesions had recurred by 24 months. In the C&C group (n = 44 lesions), the median time to healing was 35 days (range 14-330; mean 53). Six of the lesions took more than 90 days to heal. Infection developed in two patients. Recurrence occurred in four lesions over the follow-up period. Considering BD on the lower legs separately, lesions took on average 90 days to heal in the cryotherapy group (n = 23), whereas in the C&C group (n = 36) they took 39 days to heal (P < 0.001). During the procedure and the subsequent 24 h, patients were 10.4 times more likely to report pain of any degree for lesions treated by cryotherapy than by C&C (P < 0.001).

CONCLUSIONS

This study suggests a superiority of C&C over cryotherapy in the treatment of BD, especially for lesions on the lower leg. Curettage of lesions of BD is associated with a significantly shorter healing time, less pain, fewer complications and a lower recurrence rate when compared with cryotherapy.