Photodynamic therapy using topical 5-aminolaevulinic acid vs. surgery for basal cell carcinoma

Photodynamic therapy combined with surgery versus Mohs micrographic surgery for the treatment of difficult-to-treat basal cell carcinoma: A retrospective clinical study

BACKGROUND

Mohs micrographic surgery (MMS) is the preferable surgery for difficult -to-treat basal cell carcinoma (BCC) but is an expensive, labor-intensive, and time-consuming technique. The aim of this study is to compare the efficacy and safety of photodynamic therapy combined with surgery(S-PDT) versus Mohs micrographic surgery (MMS) for the treatment of difficult-to-treat BCC.

METHODS

This was a retrospective, comparative study. A total of 32 patients, 16 patients with 48 lesions, were treated with S-PDT and the other 16 patients with 17 lesions treated by MMS were enrolled in this study. Follow-up was at least 36 months posttreatment.

RESULTS

The recurrence rate was no statistical difference between the S-PDT and MMS (P = 1.000, Fishers exact test). The median follow-up was 42.5 months (range 36-63 months).Mean healing time in the S-PDT [17.9 days (SD 9.8)] is longer than in MMS [7.5 days (SD 1.5)] during follow-up(P＜0.001,Independent T test) . On the whole, the cosmetic outcome of patients in S-PDT was statistically no significant difference with that in MMS according to a 4-point scale (p = 0.719, chi-squared test).

CONCLUSIONS

S-PDT is a safe, effective, and novel cosmetic treatment, which holds the potential to be an alternative treatment to MMS for some cases.

Surgery combined with photodynamic therapy vs. surgery alone for the treatment of non-melanoma skin cancer and actinic keratosis: a retrospective cohort study

BACKGROUND

Photodynamic therapy (PDT) is an effective treatment for some non-melanoma skin cancers (NMSC) and actinic keratosis.

OBJECTIVES

To compare recurrence-free survival (RFS) rates between surgery alone and surgery with postoperative PDT in patients with NMSC in China.

METHODS & MATERIALS

This retrospective cohort study included patients with pathologically confirmed NMSC or actinic keratosis treated by surgical excision with/without PDT. A total of 125 patients were included, including 72 patients (43 females) aged 57-75 years in the surgery alone group and 53 patients (32 females) aged 61-76 years in the surgery+PDT group.

RESULTS

The most common NMSC types were squamous cell carcinoma and basal cell carcinoma, the most common lesion site was the head and neck, and the vast majority of patients had a primary disease and solitary lesions. There were no significant differences between groups in baseline characteristics. RFS rates in the surgery alone and surgery+PDT groups were, respectively, 100.0% and 98.1% at 1 week, 98.6% and 98.1% at 4 weeks, 97.2% and 98.1% at 8 weeks, 97.2% and 98.1% at 12 weeks, and 90.3% and 90.4% at 24 weeks, with no significant differences between groups.

CONCLUSION

Adjuvant PDT after surgical excision of NMSC or actinic keratosis does not provide short-term improvement in RFS, but the results need to be confirmed by a formal randomized controlled trial.

Basal Cell Carcinoma: an updated review of pathogenesis and treatment options

Basal cell carcinoma (BCC) remains the most common malignancy worldwide. BCC pathogenesis is a result of the interplay between one's environment, genetics, and phenotypic factors. BCC has a low mortality but given its increasing incidence and potential to cause local destruction thus resulting in significant morbidity, it is vital for dermatologists to remain up to date with recent updates in this malignancy's pathogenesis and treatment. This article provides a comprehensive review of the pathogenesis of BCC as well as the current treatments available and clinical trials underway. We also touch upon the updated National Comprehensive Cancer Network Clinical Practice Guidelines in Oncology in respect to BCC's recommended treatment modalities.

Implications of photodynamic cancer therapy: an overview of PDT mechanisms basically and practically

BACKGROUND

Tumor eradication is one of the most important challengeable categories in oncological studies. In this account, besides the molecular genetics methods including cell therapy, gene therapy, immunotherapy, and general cancer therapy procedures like surgery, radiotherapy, and chemotherapy, photodynamic adjuvant therapy is of great importance. Photodynamic therapy (PDT) as a relatively noninvasive therapeutic method utilizes the irradiation of an appropriate wavelength which is absorbed by a photosensitizing agent in the presence of oxygen. In this procedure, a series of events lead to the direct death of malignant cells such as damage to the microvasculature and also the induction of a local inflammatory function. PDT has participated with other treatment modalities especially in the early stage of malignant tumors and has resulted in decreasing morbidity besides improving survival rate and quality of life. High spatial resolution of PDT has attracted considerable attention in the field of image-guided photodynamic therapy combined with chemotherapy of multidrug resistance cancers. Although PDT outcomes vary across the different tumor types, minimal natural tissue toxicity, minor systemic effects, significant reduction in long-term disease, lack of innate or acquired resistance mechanisms, and excellent cosmetic effects, as well as limb function, make it a valuable treatment option for combination therapies.

SHORT CONCLUSION

In this review article, we tried to discuss the potential of PDT in the treatment of some dermatologic and solid tumors, particularly all its important mechanisms.

Antibody-Based Targeted Interventions for the Diagnosis and Treatment of Skin Cancers

BACKGROUND

Cutaneous malignancies most commonly arise from skin epidermal cells. These cancers may rapidly progress from benign to a metastatic phase. Surgical resection represents the gold standard therapeutic treatment of non-metastatic skin cancer while chemo- and/or radiotherapy are often used against metastatic tumors. However, these therapeutic treatments are limited by the development of resistance and toxic side effects, resulting from the passive accumulation of cytotoxic drugs within healthy cells.

OBJECTIVE

This review aims to elucidate how the use of monoclonal Antibodies (mAbs) targeting specific Tumor Associated Antigens (TAAs) is paving the way to improved treatment. These mAbs are used as therapeutic or diagnostic carriers that can specifically deliver cytotoxic molecules, fluorophores or radiolabels to cancer cells that overexpress specific target antigens.

RESULTS

mAbs raised against TAAs are widely in use for e.g. differential diagnosis, prognosis and therapy of skin cancers. Antibody-Drug Conjugates (ADCs) particularly show remarkable potential. The safest ADCs reported to date use non-toxic photo-activatable Photosensitizers (PSs), allowing targeted Photodynamic Therapy (PDT) resulting in targeted delivery of PS into cancer cells and selective killing after light activation without harming the normal cell population. The use of near-infrared-emitting PSs enables both diagnostic and therapeutic applications upon light activation at the specific wavelengths.

CONCLUSION

Antibody-based approaches are presenting an array of opportunities to complement and improve current methods employed for skin cancer diagnosis and treatment.

Skin Penetration Enhancement Strategies Used in the Development of Melanoma Topical Treatments

Malignant melanoma is an aggressive form of skin cancer for which there is currently no reliable therapy and is considered one of the leading health issues in the USA. At present, surgery is the most effective and acceptable treatment; however, surgical excision can be impractical in certain circumstances. Topical skin delivery of drugs using topical formulations is a potential alternative approach which can have many advantages aside from being a non-invasive delivery route. Nevertheless, the presence of the stratum corneum (SC) limits the penetration of drugs through the skin, lowering their treatment efficacy and raising concerns among physicians and patients as to their effectiveness. Currently, research groups are trying to circumvent the SC barrier by using skin penetration enhancement (SPE) strategies. The SPE strategies investigated include chemical skin penetration enhancers (CPEs), physical skin penetration enhancers (PPEs), nanocarrier systems, and a combination of SPE strategies (cream). Of these, PPEs and cream are the most advanced approaches in terms of preclinical and clinical studies, respectively.

In vitro study of enhanced photodynamic cancer cell killing effect by nanometer-thick gold nanosheets

Photodynamic therapy (PDT) by near-infrared (NIR) irradiation is a promising technique for treating various cancers. Here, we reported the development of free-standing wafer-scale Au nanosheets (NSs) that exhibited an impressive PDT effect. The Au NSs were synthesized by ionic layer epitaxy at the air-water interface with a uniform thickness in the range from 2 to 8.5 nm. These Au NSs were found very effective in generating singlet oxygen under NIR irradiation. In vitro cellular study showed that the Au NSs had very low cytotoxicity and high PDT efficiency due to their uniform 2D morphology. Au NSs could kill cancer cells after 5 min NIR irradiation with little heat generation. This performance is comparable to using 10 times mass loading of Au nanoparticles (NPs). This work suggests that two-dimensional (2D) Au NSs could be a new type of biocompatible nanomaterial for PDT of cancer with an extraordinary photon conversion and cancer cell killing efficiency.

European Dermatology Forum guidelines on topical photodynamic therapy 2019 Part 1: treatment delivery and established indications - actinic keratoses, Bowen's disease and basal cell carcinomas

Topical photodynamic therapy (PDT) is a widely approved therapy for actinic keratoses, Bowen's disease (squamous cell carcinoma in situ), superficial and certain thin basal cell carcinomas. Recurrence rates when standard treatment protocols are used are typically equivalent to existing therapies, although inferior to surgery for nodular basal cell carcinoma. PDT can be used both as lesional and field therapies and has the potential to delay/reduce the development of new lesions. A protocol using daylight to treat actinic keratoses is widely practised, with conventional PDT using a red light after typically a 3-h period of occlusion employed for other superficial skin cancer indications as well as for actinic keratoses when daylight therapy is not feasible. PDT is a well-tolerated therapy although discomfort associated with conventional protocol may require pain-reduction measures. PDT using daylight is associated with no or minimal pain and preferred by patient. There is an emerging literature on enhancing conventional PDT protocols or combined PDT with another treatment to increase response rates. This guideline, published over two parts, considers all current approved and emerging indications for the use of topical PDT in dermatology, prepared by the PDT subgroup of the European Dermatology Forum guidelines committee. It presents consensual expert recommendations reflecting current published evidence.

Topical treatments for skin cancer

Skin cancer is a broad term used to describe a number of different malignant indications of the skin. Skin cancers mostly comprise of the keratinocyte cancers [Basal Cell Carcinoma (BCC) and cutaneous Squamous Cell Carcinoma (SCC)], and melanoma. Surgical excision of these malignancies has been the preferred treatment of patients for decades. However, the decision to perform surgery can be affected by various considerations, including co-morbidities of the patient, the anatomical site of the lesion and potential intolerance for repeated excisions. Topical treatment of skin cancer may therefore be more appropriate in certain instances. Topical treatment potentially allows for higher drug levels at the tumor site, and may result in less overall toxicity than systemic agents. This review will specifically address the current agents used in topical treatment of skin cancers, and introduce emerging treatments from the natural product field that may also find utility in these indications.

Diagnosis and Management of Basal Cell Carcinoma

OPINION STATEMENT

Basal cell carcinomas (BCCs) are common skin cancers that tend to appear on sun-exposed skin. Pathobiologically, activation of the Hedgehog signaling pathway characterizes the majority of cases. In general, BCCs are slow-growing and rarely metastasize. Nevertheless, they are locally invasive and can be destructive. While typical cases are diagnosed based on clinical findings, the clinicopathological manifestations are varied. Consequently, skin biopsy is essential to confirm the diagnosis and evaluate the risk of recurrence. In the treatment of primary lesions, the initial goal is to complete tumor removal, whether by conventional surgical excision, Mohs micrographic surgery, cryosurgery, electrodesiccation and curettage, topical application of imiquimod or fluorouracil, photodynamic therapy, or radiation therapy. Of these treatments, surgical excision and Mohs surgery are the most commonly used because of their association with a low recurrence rate and the ability to confirm residual tumor pathologically. However, other treatment options may be preferred according to patient condition, tumor location, and risk of recurrence. In the treatment of metastatic or locally advanced lesions, smoothened inhibitors, which inhibit Hedgehog signaling pathway activation, were recently approved and impressive tumor shrinkage effects have been described. Although the exact prognosis of metastatic BCC has not been analyzed, it is probably poor due to the rarity of such condition. However, emerging molecular targeting agents hold therapeutic promise.

Current Basal and Squamous Cell Skin Cancer Management

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Characterize basal and squamous cell carcinomas as low or high risk based on size, location, histology, and clinical features. 2. Understand appropriate surgical margins in low- and high-risk lesions, and other management options, including Mohs micrographic surgery, electrodissection and curettage, topical agents, cryotherapy, photodynamic therapy, and radiation therapy. 3. Discuss adjuvant therapies for locally advanced and metastatic disease, including radiation therapy, chemotherapy, and targeted therapies such as hedgehog pathway inhibitors. 4. Educate patients on preventive measures such as skin examinations, sun protection, oral retinoids, and oral nicotinamide (vitamin B3). 5. Devise a reconstructive plan once clear oncologic margins are obtained.

SUMMARY

With the growing incidence of basal and squamous cell carcinoma, there is an increasing demand for appropriate oncologic management and aesthetic reconstruction. The goal of this CME article is to provide a foundation of knowledge to accurately diagnose, stage, and treat nonmelanoma skin cancers. In addition, it provides the practicing plastic surgeon alternate tools for managing these skin lesions, including topical agents, destructive therapies, and radiation therapy. Lastly, reconstructive plans for selected soft-tissue defects are discussed.

Prise en charge chirurgicale du carcinome basocellulaire

The incidence of basal cell carcinoma (BCC) is increasing as the population is aging and doubles every ten years. Surgery is the first-line treatment of BCC. Dermatological surgery is an oncological skin surgery whose first objective is to obtain a complete resection of the tumor. Its aim is also to reconstruct the defect using the optimal repair technique for the best cosmetic and scarring outcome and without functional impairment. The dermatological approach with the "oncological reading" of cutaneous tumors constitutes the essential preliminary time to the diagnosis of BCC and the identification of its limits. The perfect knowledge of the security margins in accordance with the guidelines allows a complete excision and a reconstruction in one stage under local anesthesia in the majority of cases. The surgical treatment must use 3D histology techniques or micrographic surgery to manage difficult cases of aggressive BCC in high risk zone or recurrence. Management of very aggressive BCC or locally advanced BCC is discussed in a multidisciplinary consultation by assessing the benefit/risk ratio of the surgical treatment and by identifying the appropriate surgeon after documenting the tumor, its operability and patient's adherence to the surgical treatment. © 2018. Published by Elsevier Masson SAS. All rights reserved. Cet article fait partie du numéro supplément Prise en charge des carcinomes basocellulaires difficiles à traiter réalisé avec le soutien institutionnel de Sun Pharma.

Treatments of Primary Basal Cell Carcinoma of the Skin: A Systematic Review and Network Meta-analysis

BACKGROUND

Most interventions for basal cell carcinoma (BCC) have not been compared in head-to-head randomized trials.

PURPOSE

To evaluate the comparative effectiveness and safety of treatments of primary BCC in adults.

DATA SOURCES

English-language searches of MEDLINE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Embase from inception to May 2018; reference lists of guidelines and systematic reviews; and a search of ClinicalTrials.gov in August 2016.

STUDY SELECTION

Comparative studies of treatments currently used in adults with primary BCC.

DATA EXTRACTION

One investigator extracted data on recurrence, histologic clearance, clinical clearance, cosmetic outcomes, quality of life, and mortality, and a second reviewer verified extractions. Several investigators evaluated risk of bias for each study.

DATA SYNTHESIS

Forty randomized trials and 5 nonrandomized studies compared 18 interventions in 9 categories. Relative intervention effects and mean outcome frequencies were estimated using frequentist network meta-analyses. Estimated recurrence rates were similar for excision (3.8% [95% CI, 1.5% to 9.5%]), Mohs surgery (3.8% [CI, 0.7% to 18.2%]), curettage and diathermy (6.9% [CI, 0.9% to 36.6%]), and external-beam radiation (3.5% [CI, 0.7% to 16.8%]). Recurrence rates were higher for cryotherapy (22.3% [CI, 10.2% to 42.0%]), curettage and cryotherapy (19.9% [CI, 4.6% to 56.1%]), 5-fluorouracil (18.8% [CI, 10.1% to 32.5%]), imiquimod (14.1% [CI, 5.4% to 32.4%]), and photodynamic therapy using methyl-aminolevulinic acid (18.8% [CI, 10.1% to 32.5%]) or aminolevulinic acid (16.6% [CI, 7.5% to 32.8%]). The proportion of patients reporting good or better cosmetic outcomes was better for photodynamic therapy using methyl-aminolevulinic acid (93.8% [CI, 79.2% to 98.3%]) or aminolevulinic acid (95.8% [CI, 84.2% to 99.0%]) than for excision (77.8% [CI, 44.8% to 93.8%]) or cryotherapy (51.1% [CI, 15.8% to 85.4%]). Data on quality of life and mortality were too sparse for quantitative synthesis.

LIMITATION

Data are sparse, and effect estimates are imprecise and informed by indirect comparisons.

CONCLUSION

Surgical treatments and external-beam radiation have low recurrence rates for the treatment of low-risk BCC, but substantial uncertainty exists about their comparative effectiveness versus other treatments. Gaps remain regarding high-risk BCC subtypes and important outcomes, including costs.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality. (PROSPERO: CRD42016043353).

A new optical intra-tissue fiber irradiation ALA-PDT in the treatment of acne vulgaris in rabbit model: improved safety and tolerability

Background

Photodynamic therapy with topical aminolevulinic acid (ALA-PDT) has been suggested to be effective in treatment of acne vulgaris. However, adverse events occur during and after treatment.

Objectives

To compare the efficacy and tolerability of optical intra-tissue fiber irradiation (OFI) ALA-PDT versus traditional ALA-PDT in treatment of acne vulgaris in rabbit models.

Methods

Twenty-five rabbits of clean grade were used. Twenty rabbits were randomly selected to establish acne model and the other five were used as control. Rabbits in model group (40 ears) were further divided into four groups (10 ears/group): I, OFI-ALA-PDT with the head of optical fiber inserted into the target lesion (intra-tissue); II, traditional ALA-PDT group; III, OFI group; IV, blank control group without any treatment. Uncomfortable symptoms, adverse events, and effectiveness rates were recorded on post-treatment day 14, 30, and 45.

Results

On post-treatment day 14, the effectiveness rate in OFI-ALA-PDT group was obviously higher than that of the other three groups (P<0.05). However, no improved effects were observed in OFI-ALA-PDT group on day 30 and 45. During the period of treatment, the frequencies of uncomfortable symptoms in ALA-PDT group were obviously higher than those in the other three groups (P<0.05). The adverse event rate in OFI-ALA-PDT group was obviously lower than that of the ALA-PDT group (P<0.05).

Study limitations

The unblindness of the study and temporary animal models of acne induced may hamper the assessment and monitoring of the results, and future studies are still needed to clarify it further.

Conclusion

The OFI-ALA-PDT group (intra-tissue irradiation) showed no improved efficacy on treating rabbit ear acne but had higher safety and better tolerability.

Five-Year Results of a Randomized Controlled Trial Comparing Effectiveness of Photodynamic Therapy, Topical Imiquimod, and Topical 5-Fluorouracil in Patients with Superficial Basal Cell Carcinoma

For the treatment of superficial basal cell carcinoma, a prospective, noninferiority, randomized controlled multicenter trial with 601 patients showed that 5% imiquimod cream was superior and 5-fluorouracil cream not inferior to methyl aminolevulinate photodynamic therapy (MAL-PDT) at 1 and 3 years after treatment. No definite conclusion could be drawn regarding the superiority of imiquimod over 5-fluorouracil. We now present the 5-year follow-up results according to the intention-to-treat analysis. Five years after treatment, the probability of tumor-free survival was 62.7% for methyl aminolevulinate photodynamic therapy (95% confidence interval [CI] = 55.3-69.2), 80.5% for imiquimod (95% CI = 74.0-85.6), and 70.0% for 5-fluorouracil (95% CI = 62.9-76.0). The hazard ratio for treatment failure of imiquimod and 5-fluorouracil were 0.48 (95% CI = 0.32-0.71, P < 0.001) and 0.74 (95% CI = 0.53-1.05, P = 0.09), respectively, when compared with methyl aminolevulinate photodynamic therapy. Compared with 5-fluorouracil, imiquimod showed a hazard ratio of 0.65 (95% CI 0.43-0.98, P = 0.04). In conclusion, 5 years after treatment, the results of this trial show that 5% imiquimod cream is superior to both methyl aminolevulinate photodynamic therapy and 5-fluorouracil cream in terms of efficacy for superficial basal cell carcinoma. We therefore consider 5% imiquimod cream as the first choice for noninvasive treatment in most primary superficial basal cell carcinomas.

Photodynamic Therapy and Non-Melanoma Skin Cancer

Non-melanoma skin cancer (NMSC) is the most common malignancy among the Caucasian population. Photodynamic therapy (PDT) is gaining popularity for the treatment of basal cell carcinoma (BCC), Bowen's disease (BD) and actinic keratosis (AK). A topical or systemic exogenous photosensitiser, results in selective uptake by malignant cells. Protoporphyrin IX (PpIX) is produced then activated by the introduction of a light source. Daylight-mediated MAL (methyl aminolaevulinate) PDT for AKs has the advantage of decreased pain and better patient tolerance. PDT is an effective treatment for superficial BCC, BD and both individual and field treatment of AKs. Excellent cosmesis can be achieved with high patient satisfaction. Variable results have been reported for nodular BCC, with improved outcomes following pretreatment and repeated PDT cycles. The more aggressive basisquamous, morphoeic infiltrating subtypes of BCC and invasive squamous cell carcinoma (SCC) are not suitable for PDT. Prevention of "field cancerization" in organ transplant recipients on long-term immunosuppression and patients with Gorlin syndrome (naevoid basal cell carcinoma syndrome) is a promising development. The optimisation of PDT techniques with improved photosensitiser delivery to target tissues, new generation photosensitisers and novel light sources may expand the future role of PDT in NMSC management.

Photodynamic Therapy for Non-Melanoma Skin Cancers

Non-melanoma skin cancer (NMSC) is traditionally treated with surgical excision. Nonsurgical methods such as cryotherapy and topical chemotherapeutics, amongst other treatments, are other options. Actinic keratosis (AKs) are considered precancerous lesions that eventually may progress to squamous cell carcinoma (SCC). Photodynamic therapy (PDT) offers an effective treatment for AKs, and is also effective for superficial basal cell carcinoma (BCC). Nodular BCC and Bowen's disease (SCC in situ) have shown acceptable response rates with PDT, although recurrence rates are higher for these two NMSC subtypes. Methylaminolevulinate (MAL) PDT is a more effective treatment option than 5-aminolevulinic acid (ALA) PDT for nodular BCC. Several studies have shown that PDT results in superior cosmetic outcomes compared to surgical treatment. PDT is overall well-tolerated, with pain being the most common side effect.

Therapeutic effects of topical 5-aminolevulinic acid photodynamic therapy

Objective:

To evaluate the therapeutic effects of combined 5-aminolevulinic acid (ALA) and photodynamic therapy (PDT) on genital warts and the safety.

Methods:

One hundred ten patients with genital warts who were treated in our hospital from June 2013 to October 2014 were selected. The warts and affected parts were disinfected with benzalkonium bromide solution, and the warts were covered with absorbent cotton that had already been added freshly prepared 20% ALA solution, packaged and fixed. Then they were wet-dressed in dark, into which ALA solution was added according to the proportion of 5:3:2 every 30 minutes for three consecutive hours. Afterwards, the warts were illuminated by using photodynamic laser apparatus. The clinical outcomes, adverse reactions and recurrence rates were observed.

Results:

Genital warts were relieved in 107 out of the 110 cases (cure rate: 97.3%). Male patients had significantly better treatment outcomes at the urethral orifice than those in other affected parts. In the 107 patients, the cure rate of male patients was 98.8%, and they were cured after being treated four times. In contrast, female patients, who were cured after 5 times of treatment, had the cure rate of 91.7%. Their cure rates were similar (χ²=0, P>0.05), but the males were cured after significantly fewer times of treatment than the females (t=-7.432, P<0.05). Five patients suffered from mild tingling or burning sensation upon dressing at the urethral orifice, and the others were all free from systemic adverse reactions. After illumination, a small portion of the patients had mildly red, swelling, painful affected parts, with mild edema that almost disappeared within three days. Three patients relapsed at the urethral orifice and were then cured after further treatment.

Conclusion:

ALA-PDT can treat genital warts safely with high cure rate and low recurrence rate, particularly working for those of males at the urethral orifice.

Photodynamic therapy for basal cell carcinoma

Topical photodynamic therapy is an effective and safe noninvasive treatment for low-risk basal cell carcinoma, with the advantage of an excellent cosmetic outcome. Efficacy of photodynamic therapy in basal cell carcinoma is supported by substantial research and clinical trials. In this article, we review the procedure, indications and clinical evidences for the use of photodynamic therapy in the treatment of basal cell carcinoma.

Basal cell carcinoma of the skin (part 2): diagnosis, prognosis and management

Basal cell carcinoma (BCC) is a heterogeneous malignant neoplasm with different biological and clinical behaviors, often slow growing and rarely metastatic and conveying an excellent prognosis. However, BCC is the most frequent skin cancer worldwide and can cause great morbidity, as most occur in high visible areas of the body, often relapse and may invade and destroy local tissues. This review aims to present a concise and updated overview of BCC histopathology and clinical presentation and progression. We also present a summary of currently available treatment options and some of the new promising agents.

Usefulness of Photodynamic Therapy as a Possible Therapeutic Alternative in the Treatment of Basal Cell Carcinoma

Basal cell carcinoma (BCC) is the most common cancer in individuals with fair skin type (I–II) and steadily increasing in incidence (70% of skin malignancy). It is locally invasive but metastasis is usually very rare, with an estimated incidence of 0.0028%–0.55%. Conventional therapy is surgery, especially for the H region of the face and infiltrative lesions; in case of inoperable tumors, radiotherapy is a valid option. Recently, topical photodynamic therapy (PDT) has become an effective treatment in the management of superficial and small nodular BCC. PDT is a minimally invasive procedure that involves the administration of a photo-sensibilizing agent followed by irradiation at a pre-defined wavelength; this determines the creation of reactive oxygen species that specifically destroy target cells. The only major side effect is pain, reported by some patients during the irradiation. The high cure rate and excellent cosmetic outcome requires considering this possibility for the management of patients with both sporadic and hereditary BCC. In this article, an extensive review of the recent literature was made, in order to clarify the role of PDT as a possible alternative therapeutic option in the treatment of BCC.

Effect of methylene blue-mediated photodynamic therapy for treatment of basal cell carcinoma

Photodynamic therapy (PDT) is regarded as a treatment option for basal cell carcinoma (BCC). The aim of this study is to investigate the efficacy of methylene blue (MB)-based PDT in patients suffering from nodular or ulcerative BCCs. This study is a prospective clinical trial with a 6-months follow-up. The study setting is at the Dermatology Clinic at NILES, Cairo University, Egypt. Seventeen patients complaining of nodular BCC (nBCC) and three patients complaining of ulcerative BCC (uBCC) were taken as samples. Methylene blue, the photosensitizer, was prepared in two different formulas: liposomal-loaded MB (LMB) was prepared and formulated in hydrogel (MB 0.2%) to be used topically alone for treating BCCs <2 cm in diameter or to be combined with intralesional injection (ILI) of free MB 2% aqueous solution for treating BCCs ≥2 cm in diameter. A session was performed every 2 weeks until complete response (CR) of the lesion or for a maximum of six sessions. Clinical assessments of clinical improvement, dermatological photography, monthly follow-up visits for 6 months, and skin biopsy after 3 months of follow-up to confirm the response, recurrence, or both in cases in which the clinical evaluation was ambiguous. Seventeen patients of the 20 completed the study, 11 patients achieved CR with very good cosmetic outcome, photosensitizer tolerance, and minimal reported side effects. MB is a cheap promising alternative photosensitizer for PDT of nBCC.

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.

Current evidence and applications of photodynamic therapy in dermatology

In photodynamic therapy (PDT) a photosensitizer – a molecule that is activated by light – is administered and exposed to a light source. This leads both to destruction of cells targeted by the particular type of photosensitizer, and immunomodulation. Given the ease with which photosensitizers and light can be delivered to the skin, it should come as no surprise that PDT is an increasingly utilized therapeutic in dermatology. PDT is used commonly to treat precancerous cells, sun-damaged skin, and acne. It has reportedly also been used to treat other conditions including inflammatory disorders and cutaneous infections. This review discusses the principles behind how PDT is used in dermatology, as well as evidence for current applications of PDT.

Spotlighting the role of photodynamic therapy in cutaneous malignancy: an update and expansion

BACKGROUND

Topical photodynamic therapy (PDT) is an option for the treatment of cutaneous malignancy.

OBJECTIVE

To present an update and expansion on a previous review of the use of PDT in the current literature in the treatment of actinic keratoses (AK), superficial and nodular basal cell carcinoma (sBCC, nBCC), squamous cell carcinoma (SCC), Bowen's disease, cutaneous T cell lymphoma (CTCL), malignant melanoma, and its use in chemoprevention.

METHODS

Extensive PubMed search January 2013.

RESULTS AND CONCLUSIONS

We find sufficient evidence to recommend the use of PDT in certain patients in the treatment of AK, Bowen's disease, sBCC, and nBCC. It is especially useful in those with contraindications to surgery, widespread areas of involvement, and large lesions. Not only can it be considered superior to other therapies as far as recovery time, tolerance, and cosmetic outcomes, but it also should be considered, when indicated, as first-line treatment in the above conditions. Investigations continue for the use of PDT in the treatment of melanoma, SCC, chemoprevention, and CTCL.

A light emitting diode (LED) based spatial frequency domain imaging system for optimization of photodynamic therapy of nonmelanoma skin cancer: quantitative reflectance imaging

BACKGROUND

Photodynamic therapy (PDT) offers the potential for enhanced treatment of nonmelanoma skin cancer (NMSC) with minimal scarring. Yet, PDT has not achieved consistent long term effectiveness to gain widespread clinical acceptance for treatment of skin cancer. Therapeutic response varies between practitioners, patients and lesions. One important contributing factor is the absence of quantitative tools to perform in vivo dosimetry. To this end, we have developed a new quantitative imaging device that can be used to investigate parameters related to optimizing dosimetry.

METHODS

We present a spatial frequency domain imaging (SFDI) based device designed to: (1) determine the optical properties at the therapeutic wavelength, which can inform variations in light penetration depth and (2) measure the spatially resolved oxygen saturation of the skin cancer lesions and surrounding tissue. We have applied this system to a preliminary clinical study of nine skin cancer lesions.

RESULTS

Optical properties vary greatly both spatially [101%, 48% for absorption and reduced scattering, respectively] and across patients [102%, 57%]. Blood volume maps determined using visible wavelengths (460, 525, and 630 nm) represent tissue volumes within ∼1 mm in tissue (1.17 ± 0.3 mm). Here the average total hemoglobin concentration is approximately three times greater in the lesion than that detected in normal tissue, reflecting increased vasculature typically associated with tumors. Data acquired at near infrared wavelengths (730 and 850 nm) reports tissue blood concentrations and oxygenations from the underlying dermal microvasculature (volumes reaching 4.36 ± 1.32 mm into tissue).

CONCLUSIONS

SFDI can be used to quantitatively characterize in vivo tissue optical properties that could be useful for better informing PDT treatment parameters. Specifically, this information provides spatially resolved insight into light delivery into tissue and local tissue oxygenation, thereby providing more quantitative and controlled dosimetry specific to the lesion. Ultimately, by optimizing the execution of PDT, this instrument has the potential to positively improve treatment outcomes.