Routine double treatments of superficial basal cell carcinomas using aminolaevulinic acid-based photodynamic therapy

A Clinical Trial to Determine the Impact of Tumor Size, Histological Subtype, and Vitamin D Status on the Therapeutic Response of Basal Cell Carcinoma to Photodynamic Therapy

Photodynamic therapy (PDT) with topical aminolevulinic acid (ALA) can be effective for select basal cell carcinoma (BCC) lesions. However, the histological depth and subtype of tumors that respond to PDT remain uncertain. Here, we report a clinical trial of high-dose oral Vitamin D (VD), used as a PDT neoadjuvant for BCC. In this multi-institutional, intra-patient, randomized trial, 35 patients (9 with Gorlin Syndrome) received three PDT sessions (20% ALA; 417 nm blue light) preceded by oral VD, placebo, or no pretreatment. Tumors (122 BC) were monitored using 3D photography and computer-assisted volumetric analysis. Values for absolute volume (3DAbsVol) and average height (3DAvHt) were calculated and used to quantify tumor response kinetics. From histological sections, 3DAvHt was found to correlate with actual tumor depth, although 3DAvHt is only ~10-20% of the latter. Importantly, 3DAvHt measurements revealed a distinct depth threshold that predicts PDT responsiveness. Of 122 tumors analyzed, 70% cleared after PDT; remaining tumors were micronodular or other aggressive histologic subtypes. To evaluate VD's effects upon treatment response kinetics after PDT, only 40% of original lesions were available for analysis. By stratifying remaining tumors by 3DAvHt, we found 65% of thin tumors to be VD-responsive, whereas only 28% of thick tumors responded to VD. Overall, PDT was effective for the majority of BCC lesions in our study. Tumors most likely to respond can be predicted histologically and by noninvasive 3D morphometry. For PDT-appropriate BCC lesions, neoadjuvant oral Vitamin D represents a safe and beneficial way to accelerate tumor resolution.

New, simplified versus standard photodynamic therapy (PDT) regimen for superficial and nodular basal cell carcinoma (BCC): A single-blind, non-inferiority, randomised controlled multicentre study

BACKGROUND

Topical photodynamic therapy (PDT) is an approved and widely used treatment for low-risk basal cell carcinoma (BCC), comprising two sessions with an interval of 1 week. Simplification of the treatment course can be cost-effective, easier to organize, and cause less discomfort for the patients.

METHODS AND FINDINGS

We performed an investigator-initiated, single-blind, non-inferiority, randomized controlled multicentre study with the objective of investigating whether a simpler and more flexible PDT regimen was not >10% less effective than the standard double PDT in the treatment of primary, superficial, and nodular ≤2 mm-thick BCC and evaluate the cosmetic outcome. With a non-inferiority margin of 0.1 and an expected probability complete response of 0.85, 190 tumours were required in each group. Histologically verified BCCs from seven centres in Norway were randomly assigned (1:1) to either receive a new regimen of single PDT with one possible re-treatment of non-complete responding tumours, or the standard regimen. The primary endpoint was the number of tumours with complete response or treatment failure at 36 months of follow-up, assessed by investigators blinded to the treatment regimen. Intention-to-treat and per-protocol analyses were performed. The cosmetic outcome was recorded. The study was registered with ClinicalTrials.gov, NCT-01482104, and EudraCT, 2011-004797-28. A total of 402 BCCs in 246 patients were included; 209 tumours assigned to the new and 193 to the standard regimen. After 36 months, there were 61 treatment failures with the new and 34 failures with the standard regimen. Complete response rate was 69.5% in the new and 81.1% in the standard treatment group. The difference was 11.6% (upper 97.5% CI 20.3), i.e. > than the non-inferiority margin of 10%. Cosmetic outcomes were excellent or good in 92% and 89% following the new and standard regimens, respectively.

CONCLUSIONS

Single PDT with possible re-treatment of primary, superficial, and nodular ≤ 2-mm-thick BCC was significantly less effective than the approved standard double treatment. The cosmetic outcome was favorable and comparable between the two treatment groups.

Photodynamic Therapy in Treating a Subset of Basal Cell Carcinoma: Strengths, Shortcomings, Comparisons with Surgical Modalities, and Potential Role as Adjunctive Therapy

Basal cell carcinoma (BCC) is the most common skin cancer, for which there are multiple treatment options, including the gold standard Mohs micrographic surgery (MMS), surgical excision, electrodesiccation and curettage, radiation therapy, cryosurgery, and photodynamic therapy (PDT). While PDT is currently approved for treating actinic keratosis, it has been used off-label to treat BCC patients who may not tolerate surgery or other treatment modalities. We present a review of the efficacy of these modalities and describe important considerations that affect the usage of PDT and MMS. ALA-PDT and MAL-PDT are both efficacious treatment options for lower-risk BCC that can serve as non-invasive alternatives to surgical excision with favorable cosmetic outcomes in patients unsuitable to undergo surgery. In particular, PDT may be considered an adjuvant for the prevention and treatment of BCC lesions in patients with some genetic syndromes such as Gorlin syndrome, and in combination with surgical excision in lesions presenting in certain locations. Limitations to PDT include lack of margin control to prevent recurrence, pain, and cost of certain photosensitizers. Future studies should investigate the role of PDT as adjunctive therapy, standardization of protocols, and causes and ways to address recurrence following PDT treatment.

Increased DNA repair capacity augments resistance of glioblastoma cells to photodynamic therapy

Photodynamic therapy (PDT) is a clinically approved cancer therapy of low invasiveness. The therapeutic procedure involves administering a photosensitizing drug (PS), which is then activated with monochromatic light of a specific wavelength. The photochemical reaction produces highly toxic oxygen species. The development of resistance to PDT in some cancer cells is its main limitation. Several mechanisms are known to be involved in the development of cellular defense against cytotoxic effects of PDT, including activation of antioxidant enzymes, drug efflux pumps, degradation of PS, and overexpression of protein chaperons. Another putative factor that plays an important role in the development of resistance of cancer cells to PDT seems to be DNA repair; however, it has not been well studied so far. To explore the role of DNA repair and other potential novel mechanisms associated with the resistance to PDT in the glioblastoma cells, cells stably resistant to PDT were isolated from PDT sensitive cells following repetitive PDT cycles. Duly characterization of isolated PDT-resistant glioblastoma revealed that the resistance to PDT might be a consequence of several mechanisms, including higher repair efficiency of oxidative DNA damage and repair of DNA breaks. Higher activity of APE1 endonuclease and increased expression and activation of DNA damage kinase ATM was demonstrated in the U-87 MGR cell line, suggesting and proving that they are good targets for sensitization of resistant cells to PDT.

Blue light versus red light for photodynamic therapy of basal cell carcinoma in patients with Gorlin syndrome: A bilaterally controlled comparison study

BACKGROUND

Photodynamic therapy (PDT) is a non-scarring alternative for treating basal cell carcinoma (BCC) in patients with Basal Cell Nevus Syndrome (BCNS), also known as Gorlin syndrome. In Europe, red light (635 nm) is the predominant source for PDT, whereas in the United States blue light (400 nm) is more widely available. The objective of this study was to conduct a head-to-head comparison of blue light and red light PDT in the same BCNS patients.

METHODS

In a pilot study of three patients with 141 BCC lesions, 5-aminolevulinate (20% solution) was applied to all tumors. After 4 h, half of the tumors were illuminated with blue light and the remainder with red light. To ensure safety while treating this many tumors simultaneously, light doses were escalated gradually. Six treatments were administered in three biweekly sessions over 4 months, with a final evaluation at 6 months. Tumor status was documented with high-resolution photographs. Persistent lesions were biopsied at 6 months.

RESULTS

Clearance rates after blue light (98%) were slightly better than after red light (93%), with blue light shown to be statistically non-inferior to red light. Eight suspicious lesions were biopsied, 5 after red light (5/5 were BCC) and 3 after blue light (1 was BCC). Blue light PDT was reportedly less painful.

CONCLUSION

Blue light and red light PDT appear to be equally safe and perhaps equally effective for treating BCC tumors in BCNS patients. Further studies to evaluate long-term clearance after blue light PDT are needed.

Fluorouracil Enhances Photodynamic Therapy of Squamous Cell Carcinoma via a p53-Independent Mechanism that Increases Protoporphyrin IX levels and Tumor Cell Death

Photodynamic therapy (PDT), using 5-aminolevulinic acid (ALA) to drive synthesis of protoporphryin IX (PpIX) is a promising, scar-free alternative to surgery for skin cancers, including squamous cell carcinoma (SCC) and SCC precursors called actinic keratoses. In the United States, PDT is only FDA approved for treatment of actinic keratoses; this narrow range of indications could be broadened if PDT efficacy were improved. Toward that goal, we developed a mechanism-based combination approach using 5-fluorouracil (5-FU) as a neoadjuvant for ALA-based PDT. In mouse models of SCC (orthotopic UV-induced lesions, and subcutaneous A431 and 4T1 tumors), pretreatment with 5-FU for 3 days followed by ALA for 4 hours led to large, tumor-selective increases in PpIX levels, and enhanced cell death upon illumination. Several mechanisms were identified that might explain the relatively improved therapeutic response. First, the expression of key enzymes in the heme synthesis pathway was altered, including upregulated coproporphyrinogen oxidase and downregulated ferrochelatase. Second, a 3- to 6-fold induction of p53 in 5-FU-pretreated tumors was noted. The fact that A431 contains a mutant form p53 did not prevent the development of a neoadjuvantal 5-FU effect. Furthermore, 5-FU pretreatment of 4T1 tumors (cells that completely lack p53), still led to significant beneficial inductions, that is, 2.5-fold for both PpIX and PDT-induced cell death. Thus, neoadjuvantal 5-FU combined with PDT represents a new therapeutic approach that appears useful even for p53-mutant and p53-null tumors. Mol Cancer Ther; 16(6); 1092-101. ©2017 AACR.

Optimization and therapeutic effects of PDT mediated by ALA and MAL in the treatment of cutaneous malignant lesions: A comparative study

5-aminolevulinic acid (ALA) and its methylated ester (MAL) are the most common topical agents used in photodynamic therapy (PDT) as precursors of the photosensitizer protoporphyrin IX (PpIX). The induction of newly PpIX depends on incubation time of each photosensitizer in the tissue and the presence of high intralesional porphyrin levels is an important parameter for the PDT effectiveness. This study used laser-induced fluorescence (LIF) spectroscopy to evaluate the optimum time to light exposure of PDT mediated by ALA (20% w/w) and MAL (10% w/w) to treat malignant lesions precursors of cutaneous squamous cell carcinoma induced in mice. The therapeutic effects obtained by optimized ALA- and MAL-PDT were assessed 10 and 20 days after treatments. Higher PpIX levels were evidenced in the lesions photosensitized by ALA than MAL and according to LIF measurements the PDT irradiation was performed, respectively, at 300 and 330 minutes after ALA and MAL incubation. Histopathological analysis evidenced necrosis and epithelial atrophy after 10 days of PDT using both prodrugs, as well as reepitelization and collagen deposition at 20 days. Thus, despite the distinct concentration of ALA and MAL used in the formulation of each photosensitizing cream, PDT mediated by both photosensitizing agents obtained similar therapeutic outcomes.

Unilateral Basal Cell Carcinomas: An Unusual Entity Treated with Photodynamic Therapy

Background:

Unilateral localized basal cell carcinomas are an uncommon finding that presents both a diagnostic and therapeutic challenge. Exclusion of unilateral nevoid basal cell carcinoma syndrome is indicated. There are few reports in the literature regarding this entity and even less regarding therapeutic strategies.

Objective:

We present a patient with unilateral localized basal cell carcinomas who was successfully treated with photodynamic therapy.

Methods:

Photodynamic therapy was started using Levulan® Kerastick® as previously described. The topical solution was applied to the patient's back and illuminated the following day via the BLU-U Blue Light Illuminator.

Results:

The patient tolerated the procedure well and without complications. The patient had an excellent therapeutic response with no clinically apparent basal cell carcinomas for 18 months.

Conclusions:

We report a patient with unilateral basal cell carcinomas successfully treated with photodynamic therapy. This uncommon entity represents a diagnostic challenge in its inherent absence of the classic clinical and radiographic findings of nevoid basal cell carcinoma syndrome. Like nevoid basal cell carcinoma syndrome, unilateral basal cell carcinomas poses a therapeutic challenge with the sheer number of cutaneous tumors. The use of photodynamic therapy carries a proven therapeutic efficacy, a low rate of adverse events and excellent cosmesis.

Non-melanoma Skin Cancer in Canada Chapter 4: Management of Basal Cell Carcinoma

Background

Basal cell carcinoma (BCC) is the most common malignancy. Growth of BCCs leads to local destruction of neighbouring healthy skin and underlying tissue and can result in significant functional and cosmetic morbidity.

Objective

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

Methods

Literature searches and development of graded recommendations were carried out as discussed in the accompanying Introduction.

Results

Although BCCs rarely metastasize“ they can be aggressive and disfiguring. This chapter describes the natural history and prognosis of BCCs. Risk stratification is based on clinical features” including the site and size of the tumour“ its histologic subtype (nodular vs sclerosing)” and its history of recurrence.

Conclusions

Various options should be considered for BCC treatment” including cryosurgery” curettage” and topical or photodynamic approaches, as well as fixed-margin surgery and Mohs micrographic surgery. Stratification of recurrence risk for individual BCCs determines the most appropriate therapeutic course.

Photodynamic therapy in the treatment of basal cell carcinoma: a systematic review and meta-analysis

BACKGROUND/PURPOSE

This meta-analysis was designed to compare the efficacy, cosmetic outcome and safety of photodynamic therapy (PDT) with other procedures for the treatment of primary basal cell carcinoma (BCC).

METHODS

A computerized search through electronic databases was performed to search for relevant randomized controlled trials (RCTs) published before October 2013. Only RCTs that compared PDT to non-PDT for patients with BCC were selected. The risk ratios (RRs) and 95% confidence intervals (CIs) were calculated.

RESULTS

Eight studies with a total of 1583 patients met the inclusion criteria. PDT was associated with lower complete clearance rate (RR: 0.93, 95% CI: 0.89-0.98), higher 1-year recurrence rate (RR: 12.42, 95% CI: 2.34-66.02) and 5-year recurrence rate (RR: 6.79, 95% CI: 2.43-18.96) when compared with surgical excision. There was no statistically significant difference in complete clearance rate (RR: 0.92, 95% CI: 0.85-1.00), 1-year recurrence rate (RR: 1.04, 95% CI: 0.46 to 2.39) or 5-year recurrence rate (RR: 1.08, 95% CI: 0.62-1.86) when PDT was compared with cryotherapy. PDT had higher complete clearance rate compared with placebo but no statistically significant difference in complete clearance rate and 1-year recurrence rate when compared with pharmacologic treatment (topical imiquimod and 5-fluorouracil). PDT had a significantly better cosmetic outcome than surgery and cryotherapy.

CONCLUSIONS

PDT is a useful method for the treatment of BCC, more efficient than placebo and with a similar efficiency to cryosurgery and pharmacologic treatment. Even though it is less effective than surgical excision, PDT has cosmetic advantages over surgery and cryosurgery.

Non-melanoma skin cancers: photodynamic therapy, cryotherapy, 5-fluorouracil, imiquimod, diclofenac, or what? Facts and controversies

Surgical modalities-excision, Mohs micrographic surgery, and electrodesiccation with curettage-are the preferred treatments for nonmelanoma skin cancer (NMSC). When used within guidelines, they have cure rates greater than 90%. Despite this, many other treatments have been studied and utilized for NMSC. We present a comprehensive review of the literature on these topical treatments. Photodynamic therapy (PDT) is administered under numerous and significantly varied regimens, and there are a wide range of cure rates reported. Even with aggressive regimens, PDT is not as effective as surgery is, and it is not a first-line therapy for NMSC. The cryotherapy regimen aggressive enough to adequately treat NMSC carries adverse effects and cosmetic outcomes poor enough to negate its usefulness. Topical 5-fluorouracil and imiquimod are efficacious and safe for the treatment of superficial basal cell carcinoma (BCC) but not other BCC subtypes or squamous cell carcinoma. They are self-administered twice daily for several weeks; therefore, patient and tumor selection are vital to ensuring adherence. There are currently insufficient data to support the use of topical diclofenac and ingenol mebutate for NMSC.

Do lasers or topicals really work for nonmelanoma skin cancers?

Novel strategies are urgently needed to address the millions of nonmelanoma skin cancers treated in the United States annually. The need is greatest for those patients who are poor surgical candidates or those prone to numerous nonmelanoma skin cancers and therefore at risk for marked disfigurement. Traditional treatment strategies include electrosurgery with curettage, radiation therapy, cryotherapy, excision, and Mohs micrographic surgery. Alternatives to traditional treatment, including topical medications and light or laser therapies, are becoming popular; however, there are various degrees of efficacy among these alternative tactics. These alternatives include topical retinoids, peels, 5-fluorouracil, imiquimod, photodynamic therapy, and lasers. The purpose of this paper is to review the available data regarding these alternative strategies and permit the reader to have a sense of which therapies are reasonable options for care.

Photodynamic therapy-induced immunosuppression in humans is prevented by reducing the rate of light delivery

Photodynamic therapy (PDT) of non-melanoma skin cancers currently carries failure rates of 10-40%. The optimal irradiation protocol is as yet unclear. Previous studies showed profound immunosuppression after PDT, which may compromise immune-mediated clearance of these antigenic tumors. Slower irradiation prevents immunosuppression in mice, and may be at least as effective as high-fluence-rate PDT in preliminary clinical trials. The photosensitizers 5-aminolaevulinic acid and/or methyl aminolaevulinate were applied to discrete areas on the backs of healthy Mantoux-positive volunteers, followed by narrowband red light irradiation (632 nm) at varied doses and fluence rates. Delayed type hypersensitivity (Mantoux) reactions were elicited at test sites and control sites to determine immunosuppression. Human ex vivo skin received low- and high-fluence-rate PDT and was stained for oxidative DNA photolesions. PDT caused significant, dose-responsive immunosuppression at high (75 mW cm(-2)) but not low (15 or 45 mW cm(-2)) fluence rates. DNA photolesions, which may be a trigger for immunosuppression, were observed after high-fluence-rate PDT but not when light was delivered more slowly. This study demonstrates that the current clinical PDT protocol (75 mW cm(-2)) is highly immunosuppressive. Simply reducing the rate of irradiation, while maintaining the same light dose, prevented immunosuppression and genetic damage and may have the potential to improve skin cancer outcomes.

Guidelines for practical use of MAL-PDT in non-melanoma skin cancer

Methyl aminolaevulinate photodynamic therapy is increasingly practiced in the treatment of actinic keratoses, Bowen's disease and basal cell carcinomas. This method is particularly suitable for treating multiple lesions, field cancerization and lesions in areas where a good cosmetic outcome is of importance. Good treatment routines will contribute to a favourable result. The Norwegian photodynamic therapy (PDT) group consists of medical specialists with long and extensive PDT experience. With support in the literature, this group presents guidelines for the practical use of topical PDT in non-melanoma skin cancer.

Management of superficial basal cell carcinoma: focus on imiquimod

Superficial basal cell carcinoma comprise up to 25% of all histological sub-types. They are more likely to occur on younger persons and females and although generally more common on the trunk, also occur frequently on the exposed areas of the head and neck especially in areas of high sun exposure. In the last decade, new treatment options such as topical applications that modify the immune response have been trialed for effectiveness in treating these lesions. Imiquimod 5% cream has been shown to stimulate the innate and cell mediated immune system. The short-term success of imiquimod 5% cream in randomized controlled trials comparing different treatment regimes and dosing as a treatment for small superficial basal cell carcinoma (BCC) not on the face or neck is in the range of 82% for 5 times per week application. A high proportion of participants with good response rates to topical treatment (58%–92%) experience local side effects such as itching and burning, less commonly erosion and ulceration, but the proportion of participants ceasing treatment has not been high. To date one long-term study indicates a treatment success rate of 78%–81% and that initial response is a predictor of long-term outcome. Recurrences tend to occur within the first year after treatment. Future research will compare this preparation to the gold standard treatment for superficial BCC – surgical excision.

Photodynamic therapy with 5-aminolaevulinic acid, dimethylsulfoxide and curettage in basal cell carcinoma: a 6-year clinical and histological follow-up

BACKGROUND

Long-term follow-up data are needed to evaluate treatment effect after photodynamic therapy (PDT).

OBJECTIVE

To investigate long-term clinical, histological and cosmetic follow-up results in basal cell carcinoma (BCC) after PDT, including treatment response related to patients and lesion characteristics.

MATERIALS AND METHODS

A longitudinal study of 44 patients with 60 histologically verified BCC tumours, treated with one or two sessions of dimethylsulfoxide (DMSO)-supported 5-aminolaevulinic acid--PDT following curettage, was performed. Lesions in complete remission after 3 months were followed with clinical inspection, histological investigation and evaluation of cosmetic outcome at regular intervals; long-term efficacy assessed as verified recurrence within 72 months after PDT.

RESULTS

Complete remission at 3 months was achieved in 55 lesions from 39 patients. Two patients with one lesion each died. At 72 months, 43 of 53 lesions remained disease-free (81%); 68% remained after one treatment session, and 91% remained after two treatment sessions. Recurrence of tumour occurred at 6, 12, 24 and 36 months in 2, 4, 2 and 2 lesions, respectively; clinical investigation identified 97% of them. Male sex and H-mid-face zone were significantly associated with recurrence. The cosmetic outcome at 72 months was rated as good or excellent by patients and investigators in more than 90% of evaluated cases.

CONCLUSION

DMSO-PDT following curettage is an effective treatment for BCC, with favourable long-term clinical, histopathological and cosmetic results. Clinical examination of treated lesions appears to be sufficient for long term follow up.

Bioavailability of aminolaevulinic acid and methylaminolaevulinate in basal cell carcinomas: a perfusion study using microdialysis in vivo

BACKGROUND

Photodynamic therapy is becoming a popular treatment for superficial nonmelanoma precancerous and cancerous lesions, showing excellent cosmetic results. Nevertheless, the reported cure rates vary and the transdermal penetration of drugs has been discussed as a limiting factor, particularly for treatment of nodular basal cell carcinoma (BCC).

OBJECTIVES

To investigate the transdermal penetration of aminolaevulinic acid (ALA) and methylaminolaevulinate (MAL) in BCC in vivo using a microdialysis technique. The different prodrugs were compared and the effect of curettage was studied.

METHODS

Twenty patients with 27 histologically verified BCCs (13 superficial, 14 nodular) were included. All lesions were located at the front of the body (head and face excluded). The first 10 patients included were treated with MAL (13 BCCs), and the following 10 patients with ALA (14 BCCs). A light curettage was performed on every second lesion (curettage, n = 13; noncurettage, n = 14). Microdialysis catheters were inserted into the tumours at tissue depths varying from 0.4 to 1.9 mm. Dialysates were collected at 15-30-min intervals for 4 h and the interstitial concentrations of MAL and ALA were determined using high-performance liquid chromatography.

RESULTS

No significant difference in interstitial drug concentration was observed between lesions treated with ALA or MAL during the 4-h measurement period. However, for the lesions with deeper catheter locations, i.e. at or below 1 mm (n = 11), drug concentrations above the detection limit were obtained in only six lesions. All but one BCC with superficial catheter location, i.e. < 1 mm (n = 16), exhibited detectable drug concentration (P = 0.026). The interstitial peak concentrations were reached within 90 min in 23 of the 27 BCCs, but were not found to be correlated with the depth of the catheters. No difference was found when comparing superficial and nodular BCCs, and the effect of curettage was found to be negligible.

CONCLUSIONS

The results imply that there is no significant difference in transdermal penetration of ALA and MAL in tumour tissue. Detectable levels of drug were not obtained in almost 50% of the lesions where catheters were situated 1-1.9 mm in the lesion. Curettage was not found to affect the interstitial concentration, indicating that penetration of drug indeed might be a problem when treating BCCs thicker than 1 mm.

A terapia fotodinâmica com ácido 5-aminolevulínico como modalidade de tratamento para neoplasias cutâneas não-melanoma

FUNDAMENTOS: A terapia fotodinâmica baseia-se na associação de fonte de luz e fotossensibilizador para destruir seletivamente as células. OBJETIVO: Avaliar os efeitos imediatos e tardios, a resposta clínica e os resultados estéticos da terapia fotodinâmica com ácido 5-aminolevulínico em neoplasias cutâneas não-melanoma. MÉTODOS: Trinta e quatro lesões, sendo 19 disceratoses de Bowen e 15 carcinomas basocelulares, foram submetidas à aplicação tópica e oclusiva do ácido 5-aminolevulínico a 20%, por seis horas, e posteriormente a sessão única de laser de diodo (630nm). RESULTADOS: Foram registrados: sensação de queimação durante as sessões; eritema, edema e erosões, nas primeiras 72 horas; cicatrização em média de quatro semanas; resultados estéticos variáveis de excelentes a bons. Aos três meses, a resposta clínica foi de 91,2%, sendo reduzida, aos 18 meses, para 73,3%, de modo similar tanto para disceratose de Bowen (72,2%) quanto para carcinoma basocelular (75%). Foi evidenciada relação de tendência linear entre a redução da freqüência da resposta clínica e o aumento da dimensão das neoplasias cutâneas não-melanoma (p<0,001). CONCLUSÃO: A terapia fotodinâmica com ácido 5-aminolevulínico tópico mostrou destacadas vantagens: minimamente invasiva no tratamento de lesões múltiplas em sessão única ou em sítios de pobre cicatrização com superioridade dos resultados estéticos. O tipo/subtipo(clínico e histopatológico), a dimensão e o adequado seguimento devem ser considerados para a sua indicação no tratamento de neoplasias cutâneas não-melanoma.

Photodynamische Therapie bei epithelialen Hauttumoren

During the last years photodynamic therapy (PDT) has progressively established itself as a standard treatment for non-melanoma skin cancer. A number of clinical studies have demonstrated its efficacy--also compared to other treatment modalities--as well as good acceptance by patients and outstanding cosmetic results. For Bowen disease and superficial basal cell carcinoma, PDT can be regarded as the first-line non-invasive treatment. In the treatment of actinic keratoses PDT should be considered when cosmesis is crucial or in cases of field cancerization. In nodular basal cell carcinoma, effectiveness for lesions up to a thickness of 2 mm is well documented. In summary the evidence level seems sufficient to regard PDT as valuable treatment modality of which patients should not be deprived.

Aminolevulinic Acid Photodynamic Therapy for Skin Cancers

Aminolevulinic acid photodynamic therapy (ALA-PDT) is an effective and noninvasive therapy for superficial basal cell carcinoma (BCC) and Bowen's disease. It also may have a role in the treatment of nodular BCC and other cutaneous malignancies, including localized cutaneous lymphomas. ALA-PDT offers multiple advantages over traditional treatments, including little to no scarring, excellent cosmetic results, and the ability to treat multiple lesions simultaneously. It is not an effective therapy for aggressive subtypes of BCC or for invasive squamous cell carcinoma. Finally, ALA-PDT may be a useful way to prevent new skin cancers in certain high-risk patients.

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.

Fractionated Illumination Significantly Improves the Response of Superficial Basal Cell Carcinoma to Aminolevulinic Acid Photodynamic Therapy

Photodynamic therapy (PDT) of superficial basal cell carcinoma (sBCC) using topical 5-aminolevulinic acid (ALA) and a light fluence of 75-100 J cm(-2) yields unsatisfactory long-term results. In several animal models, illumination with two light fractions 2 hours apart was considerably more effective than single illumination. Response is further enhanced if the fluence of the first light fraction is reduced, although the cumulative fluence is maintained. We compared the response of sBCC to a single illumination and 2-fold illumination scheme in which two light fractions of 20 and 80 J cm(-2) are performed 4 and 6 hours after the application of a single dose of 20% ALA. We randomly assigned 154 patients with a total of 505 primary sBCC into two treatment groups. Two hundred and forty-three lesions were treated using a single illumination of 75 J cm(-2) at a fluence rate of 50 mW cm(-2). Fractionated PDT, at the same fluence rate, was performed on 262 lesions. The complete response (CR) following a 2-fold illumination scheme is significantly greater than that following a single light fraction (P=0.002, log-rank test). Twelve months after therapy, CR rate to a 2-fold illumination is 97%, whereas the CR to a single illumination is 89%.

A clinical review of PDT for cutaneous malignancies

More critical than for most other anatomy, intervention to cutaneous malignancy must not only be therapeutically successful but also achieve excellent cosmetic and functional outcome. As it can achieve those ends, PDT has moved to the forefront in the management of skin cancer. A number of well designed clinical trials and large patient series have reported outstanding outcomes for many histologies. This paper will review the rationale and outcomes of cutaneous PDT to malignancy using both topical and systemic photosensitizers. The benefits and drawbacks of cutaneous PDT are also examined.

Unilateral Basal Cell Carcinomas: An Unusual Entity Treated with Photodynamic Therapy

BACKGROUND

Unilateral localized basal cell carcinomas are an uncommon finding that presents both a diagnostic and therapeutic challenge. Exclusion of unilateral nevoid basal cell carcinoma syndrome is indicated. There are few reports in the literature regarding this entity and even less regarding therapeutic strategies.

OBJECTIVE

We present a patient with unilateral localized basal cell carcinomas who was successfully treated with photodynamic therapy.

METHODS

Photodynamic therapy was started using Levulan) Kerastick) as previously described. The topical solution was applied to the patient's back and illuminated the following day via the BLU-U Blue Light Illuminator.

RESULTS

The patient tolerated the procedure well and without complications. The patient had an excellent therapeutic response with no clinically apparent basal cell carcinomas for 18 months.

CONCLUSIONS

We report a patient with unilateral basal cell carcinomas successfully treated with photodynamic therapy. This uncommon entity represents a diagnostic challenge in its inherent absence of the classic clinical and radiographic findings of nevoid basal cell carcinoma syndrome. Like nevoid basal cell carcinoma syndrome, unilateral basal cell carcinomas poses a therapeutic challenge with the sheer number of cutaneous tumors. The use of photodynamic therapy carries a proven therapeutic efficacy, a low rate of adverse events and excellent cosmesis.

Current modalities and new advances in the treatment of basal cell carcinoma

Basal cell carcinoma (BCC) is one of the most common cancers. Surgical extirpation is currently the standard of care for BCC, which is associated with several advantages and disadvantages. Procedures such as surgical excision used to treat superficial BCC (sBCC) and nodular BCC (nBCC) may have high 5-year recurrence rates if tumors are not completely excised. Curettage with electrodesiccation is a common method for treating primary BCC. However, multiple cycles are recommended and the procedure can have unsatisfactory cosmetic results (e.g. scarring and hypopigmentation). Mohs micrographic surgery has a low rate of disease recurrence but is a specialized procedure usually limited to specific indications (e.g. high-risk tumors). Cryosurgery and photodynamic therapy require multiple cycles and are associated with variable cosmetic outcomes and recurrence rates. As with any procedure, potential risks and patient quality-of-life issues need to be considered. In addition, substantial patient and healthcare provider inconvenience limit the practical utility of some modalities. Pharmacologic interventions provide another treatment option as adjunctive or monotherapy. Investigations of imiquimod, a novel immune response modifier, have indicated that this topical, noninvasive agent is safe and well tolerated and may be efficacious in the treatment of BCC. This review will highlight the role of standard treatment modalities and introduce new advances in the treatment of BCC.

Oleic acid as optimizer of the skin delivery of 5-aminolevulinic acid in photodynamic therapy

PURPOSE

In photodynamic therapy (PDT), topically applied aminolevulinic acid (5-ALA) is converted to protoporphyrin IX (PpIX), which upon light excitation induces tumor destruction. To optimize 5-ALA-PDT via improving the highly hydrophilic 5-ALA limited penetration into the skin, we propose the use of the known skin penetration enhancer, oleic acid (OA).

METHODS

In vitro skin penetration and retention of 5-ALA (1% w/w) were measured in the presence or absence of OA (2.5, 5.0, and 10.0% w/w) in propylene glycol (PG) using porcine ear skin as the membrane. In vivo accumulation of PpIX, 4 h after application, was determined fluorometrically in healthy mice skin by chemical extraction of skin samples. In vivo PpIX fluorescence kinetics was also investigated by noninvasive techniques using an optical fiber probe, for 30 min up to 24 h after topical application of 1.0% 5-ALA + 10.0% OA in PG on hairless mice skins.

RESULTS

The flux and in vitro retention of 5-ALA in viable epidermis increased in the presence of 10.0% (w/w) OA. The amounts of PpIX, evaluated both by chemical tissue extractions and in vivo measurements by an optical fiber probe, increased after applying 5-ALA formulations containing 5.0 or 10.0% OA. Moreover, in vivo kinetic studies showed an increase in skin PpIX accumulation when formulations containing 10% OA were used; PpIX accumulation was also maintained longer compared to controls.

CONCLUSIONS

Both in vitro and in vivo results show the OA potential as an optimizer of 5-ALA skin delivery.

A dose ranging study of photodynamic therapy with porfimer sodium (Photofrin®) for treatment of basal cell carcinoma

BACKGROUND AND OBJECTIVES

While basal cell carcinoma (BCC) is effectively treated by several methods, many patients with numerous or frequently occurring lesions seek alternatives that can treat multiple cancers, with improved cosmetic outcome. PDT for esophageal and lung carcinomas is approved at a porfimer sodium (Photofrin) dose of 2 mg/kg, but lower doses increase selectivity and decrease both cutaneous phototoxicity and cost. We evaluated low doses of porfimer sodium PDT for treatment of multiple BCC.

MATERIALS AND METHODS

Seventy-seven patients with 2,041 BCC were injected with 0.75, 0.875, or 1.0 mg/kg porfimer sodium and treated 2 days later with 630-nm light. Clinical responses were determined at 6 months, then periodically to 5 years.

RESULTS

Increasing porfimer sodium dose increased complete responses (CR), with initial CR rates of 72.7% (66-78%, 95% CI), 79.9% (73-86%, 95% CI), and 92.2% (91-93%, 95% CI), albeit with some lower selectivity at the highest dose. At 1 mg/kg, 5-year recurrence rates were 28% (21-35%, 95% CI) and 15% (11-18%, 95% CI) for sporadic and nevoid basal cell carcinoma syndrome (NBCCS) lesions, respectively.

CONCLUSIONS

This is the largest dose-ranging study of porfimer sodium, and the largest number of lesions treated in a single study. We found that with 1 mg/kg porfimer sodium, PDT can be a selective and durable treatment for sporadic and NBCCS-associated BCC.

Photodynamic therapy in dermatology - an update

Topical photodynamic therapy (PDT) is a well-established treatment modality which has mainly shown to be effective for dermatooncologic conditions like actinic keratoses (AK), Bowen's disease, in situ squamous cell carcinoma and superficial basal cell carcinoma (BCC). However, a therapeutical benefit of PDT is also evident for inflammatory dermatoses like localized scleroderma, acne vulgaris and granuloma annulare. Recent work has been focused on the development and evaluation of topical photosensitizers like the heme precursor 5-aminolevulinic acid (5-ALA) or its methyl ester (methyl aminolevulinate) inducing photosensitizing porphyrins. These drugs do not induce strong generalized cutaneous photosensitization like the systemically applied porphyrins or their derivatives. For dermatological purposes, incoherent lamps or light-emitting diode arrays can be used for light activation. Depending on the applied light dose and the concentration of the photosensitizer either cytotoxic effects resulting in tumor destruction or immunomodulatory effects improving the inflammatory conditions occur. Treating superficial oncologic lesions (tumor thickness <2-3 mm) cure rates achieved by PDT are equal to the cure rates of the respective standard therapeutic procedure. The benefits of PDT are the low level of invasiveness and the excellent cosmetic results after treatment.

New proposal for the treatment of nodular basal cell carcinoma with intralesional 5-aminolevulinic acid

Photodynamic therapy (PDT) is a treatment modality using a photosensitizer, light and oxygen to cause photochemically-induced selective cell death. Topical PDT is most suitable for thin lesions such as superficial basal cell carcinoma and actinic keratoses in dermatology. Results with PDT as treatment of thicker lesions such as nodular basal cell carcinoma appear to have a limited role because the photosensitizer or the light cannot penetrate deeply enough into the thicker tumor volume. In this preliminary study we use intralesional administration of 5-aminolevulinic acid to enhance the efficacy of the photosensitivity of nodular basal cell carcinomas, thus improving clinical cure.

Cyclooxygenase-2 is a possible target of treatment approach in conjunction with photodynamic therapy for various disorders in skin and oral cavity

BACKGROUND

Anti-cancer effects of cyclooxygenase (COX)-2 inhibitors have been reported, but not fully investigated in skin and oral diseases. 5-aminolaevulinic acid (ALA)-based photodynamic therapy (PDT) for treating those patients with skin and oral lesions is a highly sophisticated procedure, but the incidence of disease recurrence after treatment is rather significant.

OBJECTIVE

To confirm that COX-2 could be a molecular target in adjunctive therapy to ALA-based PDT, we investigated (i) COX-2 expression in various skin and oral diseases, and (ii) the inhibitory effects on cellular growth of COX-2 selective inhibitor (nimesulide), ALA-based PDT and their combination on human oral squamous cell carcinoma (SCC) cell lines.

METHODS

A total of 129 biopsy samples from the skin and oral mucosal lesions were tested immunohistochemically for COX-2 expression. Then the in vitro effects of nimesulide, ALA-based PDT, and their combination were determined on two SCC cell lines, HSC-2 and HSC-4. Three different methods (MTT assay, double-staining for annexin V and propidium iodide, caspase-3/CPP32 fluorometric protease assay) were applied for evaluation of their inhibitory effects on these two cell lines.

RESULTS

Among the skin diseases, a considerable number of COX-2 high expressers were found in actinic keratosis (15 of 25, 60%), Bowen's disease (13 of 17, 76%) and extramammary Paget's disease (15 of 15, 100%). In contrast, only one of 33 (3%) basal cell carcinoma tumours was a COX-2 high expresser. Among the oral mucosal biopsies, the proportion of COX-2 high expressers increased gradually from hyperplasia (one of six, 17%) through mild dysplasia (five of eight, 63%) and moderate dysplasia (20 of 23, 87%) to severe dysplasia (two of two, 100%). Nimesulide had an inhibitory effect in vitro on HSC-2 (proven to be a COX-2 high expresser), but not on HSC-4 (a COX-2 non-expresser). While ALA-based PDT showed an inhibitory effect on both HSC-2 and HSC-4, most importantly the combination of nimesulide and ALA-based PDT demonstrated a significant synergistic effect on the cellular growth inhibition of only HSC-2, but not of HSC-4.

CONCLUSIONS

Our study strongly suggests that COX-2 can be one of the molecular targets in treating various skin and oral diseases. The results from our in vitro experiments also prompt us to develop a new protocol with a combination of COX-2 selective inhibitor and ALA-based PDT for more effective treatment of those diseases.

delta-Aminolevulinic Acid and Blue Light Photodynamic Therapy for Treatment of Multiple Basal Cell Carcinomas in Two Patients with Nevoid Basal Cell Carcinoma Syndrome

BACKGROUND

Patients with nevoid basal cell carcinoma syndrome suffer from multiple basal cell carcinomas, requiring numerous surgical procedures that over time leave them with multiple disfiguring scars. Photodynamic therapy with delta-aminolevulinic acid using red light (approximately 630 nm) sources has been reported as effective in treatment of superficial and small nodular basal cell carcinomas. To our knowledge, the blue light source (417 nm peak irradiance) approved by the FDA for treatment of actinic keratoses has not been used for photodynamic therapy with delta-aminolevulinic acid of basal cell carcinoma.

OBJECTIVE

We report treatment of two nevoid basal cell carcinoma syndrome patients, women aged 21 and 47, with 20%delta-aminolevulinic acid solution and 417-nm blue light source (irradiance 10 mW/cm(2)).

METHODS

delta-Aminolevulinic acid was applied topically on lesions 1 to 5 hr before light treatment. Lesions were illuminated with 417+/-5-nm blue light for 1000 sec (10 J/cm(2)). Two consecutive treatments 1 week apart were administered as a therapeutic course. Each patient underwent two courses of photodynamic therapy with delta-aminolevulinic acid 2 to 4 months apart. The reported assessment was made 8 months after initial treatment. In most sessions the entire face, rather than visible basal cell carcinomas only, was treated. The treated basal cell carcinomas were clinically subdivided to superficial or nodular type guided by their morphologic features. A total of 9 superficial and 16 nodular basal cell carcinomas on the face and 27 superficial basal cell carcinomas on the lower extremities were treated.

RESULTS

Complete clinical response was observed in 8 of 9 (89%) superficial basal cell carcinomas and 5 of 16 (31%) nodular basal cell carcinomas on the face and in 18 of 27 (67%) of superficial basal cell carcinomas on the lower extremities. The remaining 21 lesions showed partial clinical resolution. No new basal cell carcinomas were observed during the 8-month follow-up period in areas treated with a broad application technique. Resolution of the lesions was accompanied by an excellent cosmetic outcome and decreased prominence of old surgical scars in the more severely affected patient. Treatments were well tolerated, but associated with moderate to severe stinging during illumination.

CONCLUSION

To our knowledge this is the first use of photodynamic therapy with delta-aminolevulinic acid with 417-nm blue light for treatment of multiple basal cell carcinomas in patients with nevoid basal cell carcinoma syndrome. Our clinical results demonstrate that the blue light reduces cutaneous tumor burden in such patients. Further studies are needed to confirm that broad-area photodynamic therapy with delta-aminolevulinic acid may eradicate subclinical tumors in nevoid basal cell carcinoma syndrome sufferers, as suggested by a strikingly decreased incidence of new basal cell carcinomas in our patients.

Topical photodynamic therapy in clinical dermatology

The growing incidence of cutaneous malignancies each year necessitates the development of new and more effective methods for both the diagnosis and the treatment of cancerous lesions, while assuring better cosmetic results and improving patient satisfaction. With that in mind, the use of topical photodynamic therapy (PDT) has been explored in the treatment as well as the diagnosis of various cutaneous malignancies. Using the intrinsic cellular haem biosynthetic pathway and principles of photoillumination, topical PDT carries the goal of selectively targeting abnormal cells, while preserving the normal surrounding structures. This paper will discuss the various applications and data on the use of topical PDT in dermatology.