MAL-PDT for difficult to treat nonmelanoma skin cancer

5-Aminolevulinic Acid-Mediated Photodynamic Therapy Improves Vocal Fold Wound Healing in Rats

OBJECTIVE

Studies showed that photodynamic therapy (PDT) might be able to prevent vocal fold scar formation when treating laryngeal lesions. We aim to investigate if PDT improves vocal wound healing and reduces scar formation in both prophylactic and remodeling procedures performed in vivo.

STUDY DESIGN

In vivo.

METHODS

Vocal fold stripping was performed in Sprague-Dawley rats. PDT was performed with intraperitoneal injection of 100 mg/kg 5-Aminolevulinic Acid (5-ALA) and 635 nm laser irradiation of 20, 40, and 60 J/cm² . PDT was performed immediately after surgery to study the prophylactic effect and 4 weeks after surgery to study the remodeling effect. Gene expression was evaluated with real-time PCR at 1 week after PDT. Histologic evaluations were performed 12 weeks after PDT, including hematoxylin-eosin, Masson, Alcian blue staining, and immunohistochemical staining of collagen I and III.

RESULTS

PDT induced similar effects on the vocal fold wound healing outcomes in both prophylactic and remodeling procedures. Expression of MMP8, MMP13, HAS2, and TGFβ1 was significantly elevated. Histologic evaluation revealed significantly increased thickness, decreased density of collagen, and increased deposition of hyaluronic acid in the lamina propria. Immunohistochemistry also revealed better distribution and reduced density of collagen I and III. The most obvious changes were seen in the 60 J/cm² PDT group.

CONCLUSION

PDT could significantly improve vocal wound healing by providing both prophylactic effects and remodeling effects. It may be a minimally invasive treatment for vocal fold lesions with slight vocal scarring, and may be used to treat acute or chronic vocal injury to reduce vocal scarring.

LEVEL OF EVIDENCE

N/A Laryngoscope, 133:1943-1951, 2023.

Precision Killing of Sinoporphyrin Sodium-Mediated Photodynamic Therapy against Malignant Tumor Cells

Photodynamic therapy (PDT) has significant advantages in the treatment of malignant tumors, such as high efficiency, minimal invasion and less side effects, and it can preserve the integrity and quality of the organs. The power density, irradiation time and photosensitizer (PS) concentration are three main parameters that play important roles in killing tumor cells. However, until now, the underlying relationships among them for PDT outcomes have been unclear. In this study, human malignant glioblastoma U-118MG and melanoma A375 cells were selected, and the product of the power density, irradiation time and PS concentration was defined as the total photodynamic parameter (TPP), in order to investigate the mechanisms of PS sinoporphyrin sodium (DVDMS)-mediated PDT (DVDMS-PDT). The results showed that the survival rates of the U-118MG and A375 cells were negatively correlated with the TPP value in the curve, and the correlation exactly filed an e-exponential function. Moreover, according to the formula, we realized controllable killing effects of the tumor cells by randomly adjusting the three parameters, and we finally verified the accuracy and repeatability of the formula. In conclusion, the establishment and implementation of a newly functional relationship among the PDT parameters are essential for predicting PDT outcomes and providing personalized precise treatment, and they are contributive to the development of PDT dosimetry.

TGFβ1 Secreted by Cancer-Associated Fibroblasts as an Inductor of Resistance to Photodynamic Therapy in Squamous Cell Carcinoma Cells

Simple Summary

Photodynamic therapy (PDT) is used for the treatment of in situ cutaneous squamous cell carcinoma (cSCC), the second most common form of skin cancer, as well as for its precancerous form, actinic keratosis. However, relapses after the treatment can occur. Transforming growth factor β1 (TGFβ1) produced by cancer-associated fibroblasts (CAFs) in the tumor microenvironment has been pointed as a key player in the development of cSCC resistance to other therapies, such as chemotherapy. Here, we demonstrate that TGFβ1 produced by CAFs isolated from patients with cSCC can drive resistance to PDT in SCC cells. This finding opens up novel possibilities for strategy optimization in the field of cSCC resistance to PDT and highlights CAF-derived TGFβ1 as a potential target to improve the efficacy of PDT.

Abstract

As an important component of tumor microenvironment, cancer-associated fibroblasts (CAFs) have lately gained prominence owing to their crucial role in the resistance to therapies. Photodynamic therapy (PDT) stands out as a successful therapeutic strategy to treat cutaneous squamous cell carcinoma. In this study, we demonstrate that the transforming growth factor β1 (TGFβ1) cytokine secreted by CAFs isolated from patients with SCC can drive resistance to PDT in epithelial SCC cells. To this end, CAFs obtained from patients with in situ cSCC were firstly characterized based on the expression levels of paramount markers as well as the levels of TGFβ1 secreted to the extracellular environment. On a step forward, two established human cSCC cell lines (A431 and SCC13) were pre-treated with conditioned medium obtained from the selected CAF cultures. The CAF-derived conditioned medium effectively induced resistance to PDT in A431 cells through a reduction in the cell proliferation rate. This resistance effect was recapitulated by treating with recombinant TGFβ1 and abolished by using the SB525334 TGFβ1 receptor inhibitor, providing robust evidence of the role of TGFβ1 secreted by CAFs in the development of resistance to PDT in this cell line. Conversely, higher levels of recombinant TGFβ1 were needed to reduce cell proliferation in SCC13 cells, and no induction of resistance to PDT was observed in this cell line in response to CAF-derived conditioned medium. Interestingly, we probed that the comparatively higher intrinsic resistance to PDT of SCC13 cells was mediated by the elevated levels of TGFβ1 secreted by this cell line. Our results point at this feature as a promising biomarker to predict both the suitability of PDT and the chances to optimize the treatment by targeting CAF-derived TGFβ1 in the road to a more personalized treatment of particular cSCC tumors.

Reducing non-melanoma skin cancer risk in renal transplant recipients

With an increasing number of renal transplant recipients (RTRs) and improving patient survival, a higher incidence of non-melanoma skin cancer (NMSC) has been observed. NMSC in RTRs are often more numerous and biologically more aggressive than the general population, thus contributing towards an increase in morbidity and to a lesser degree, mortality. The resultant cumulative health and financial burden is a recognized concern. Proposed strategies in mitigating risks of developing NMSC and early therapeutic options thereof include tailored modification of immunosuppressants in conjunction with sun protection in all transplant patients. This review highlights the clinical and financial burden of transplant-associated skin cancers, carcinogenic mechanisms in association with immunosuppression, importance of skin cancer awareness campaign and integrated transplant skin clinic, and the potential role of chemoprotective agents. A scheme is proposed for primary and secondary prevention of NMSC based on the available evidence.

Basal Cell Carcinoma Review

Basal cell carcinoma (BCC) is the most common malignancy and the incidence is rising. BCCs have low mortality but can cause significant morbidity primarily through local destruction. The pathogenesis is linked to the interplay between environmental and patient-derived characteristics. There are multiple therapeutic modalities, and appropriate selection requires knowledge of complications, cosmetic outcomes, and recurrence rates. This article reviews the epidemiology, staging, treatment, and prevention of BCC.

A prospective study of pain control by a 2-step irradiance schedule during topical photodynamic therapy of nonmelanoma skin cancer

BACKGROUND

Topical photodynamic therapy (PDT) for selected nonmelanoma skin cancer using 5-aminolevulinic acid (ALA) or methyl aminolevulinate (MAL) has yielded high long-term complete response rates with very good cosmesis. Pain during light activation of the photosensitizer can be a serious adverse event. A 2-step irradiance protocol has previously been shown to minimize ALA-PDT pain.

OBJECTIVE

To determine the irradiance-dependent pain threshold for MAL-PDT, to adapt the 2-step protocol to a light-emitting diode (LED) light source, and assess clinical response.

METHODS

In this prospective study, 25 superficial basal cell carcinoma (sBCC) received an initial irradiance by laser at 40 or 50 mW/cm², or LED at 35 mW/cm² followed by an irradiance at 70 mW/cm² for a total of 75 J/cm². Pain levels were recorded for both irradiance steps. Efficacy was assessed at 6, 12, or 24 months.

RESULTS

Pain was mild in the 40/70 mW/cm² laser cohort. Three instances of irradiance-limiting pain occurred at 50/70 mW/cm². Pain was minimal in the 35/70 mW/cm² LED cohort. Clinical response rates were 80% in the 50/70 mW/cm² laser cohort and 90% in the 35/70 mW/cm² LED cohort.

CONCLUSION

Topical PDT can be effectively delivered to sBCC with minimal treatment-related pain by a 2-step irradiance protocol.

Squamous cell carcinoma of the skin: epidemiology, classification, management, and novel trends

Squamous cell carcinoma (SCC) is the second most common non-melanoma skin cancer. It originates from epidermal keratinocytes or adnexal structures (such as eccrine glands or pilosebaceous units). We describe the salient features of cutaneous SCC. We also review novel classification schemes proposed during the last decade which attempt to stratify SCC lesions based on prognosis. Biopsy leads to definitive diagnosis. Treatment includes surgical excision; Mohs micrographic surgery produces excellent cure rates and spares the maximal amount of tissue. Other modalities include electrodessication and curettage, cryosurgery, radiotherapy, topical medications, photodynamic therapy, and systemic therapy. Management and follow-up depend on the risk stratification of individual lesions.

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.

Topical photodynamic therapy following excisional wounding of human skin increases production of transforming growth factor-β3 and matrix metalloproteinases 1 and 9, with associated improvement in dermal matrix organization

BACKGROUND

Animal studies report photodynamic therapy (PDT) to improve healing of excisional wounds; the mechanism is uncertain and equivalent human studies are lacking.

OBJECTIVES

To explore the impact of methyl aminolaevulinate (MAL)-PDT on clinical and microscopic parameters of human cutaneous excisional wound healing, examining potential modulation through production of transforming growth factor (TGF)-β isoforms.

METHODS

In 27 healthy older men (60-77 years), a 4-mm punch biopsy wound was created in skin of the upper inner arm and treated with MAL-PDT three times over 5 days. An identical control wound to the contralateral arm was untreated and both wounds left to heal by secondary intention. Wounds were re-excised during the inflammatory phase (7 days, n = 10), matrix remodelling (3 weeks, n = 8) and cosmetic outcome/dermal structure (9 months, n = 9). Production of TGF-β1, TGF-β3 and matrix metalloproteinases (MMPs) was assessed by immunohistochemistry alongside microscopic measurement of wound size/area and clinical assessment of wound appearance.

RESULTS

MAL-PDT delayed re-epithelialization at 7 days, associated with increased inflammation. However, 3 weeks postwounding, treated wounds were smaller with higher production of MMP-1 (P = 0·01), MMP-9 (P = 0·04) and TGF-β3 (P = 0·03). TGF-β1 was lower than control at 7 days and higher at 3 weeks (both P = 0·03). At 9 months, MAL-PDT-treated wounds showed greater, more ordered deposition of collagen I, collagen III and elastin (all P < 0·05).

CONCLUSIONS

MAL-PDT increases MMP-1, MMP-9 and TGF-β3 production during matrix remodelling, ultimately producing scars with improved dermal matrix architecture.

Cellular intrinsic factors involved in the resistance of squamous cell carcinoma to photodynamic therapy

Photodynamic therapy (PDT) is widely used to treat non-melanoma skin cancer. However, some patients affected with squamous cell carcinoma (SCC) do not respond adequately to PDT with methyl-δ-aminolevulinic acid (MAL-PDT) and the tumors acquire an infiltrative phenotype and became histologically more aggressive, less differentiated, and more fibroblastic. To search for potential factors implicated in SCC resistance to PDT, we have used the SCC-13 cell line (parental) and resistant SCC-13 cells obtained by repeated MAL-PDT treatments (5th and 10th PDT-resistant generations). Xenografts assays in immunodeficient mice showed that the tumors generated by resistant cells were bigger than those induced by parental cells. Comparative genomic hybridization array (aCGH) showed that the three cell types presented amplicons in 3p12.1 CADM2, 7p11.2 EFGR, and 11q13.3 CCND1 genes. The 5th and 10th PDT-resistant cells showed an amplicon in 5q11.2 MAP3K1, which was not present in parental cells. The changes detected by aCGH on CCND1, EFGR, and MAP3K1 were confirmed in extracts of SCC-13 cells by reverse-transcriptase PCR and by western blot, and by immunohistochemistry in human biopsies from persistent tumors after MAL-PDT. Our data suggest that genomic imbalances related to CCND1, EFGR, and particularly MAP3K1 seem to be involved in the development of the resistance of SCC to PDT.

Nonmelanoma skin cancer

Nonmelanoma skin cancer (NMSC) represents the most common form of cancer in Caucasians, with continuing increase in incidence worldwide. Basal cell carcinoma (BCC) accounts for 75% of cases of NMSC, and squamous cell carcinoma (SCC) accounts for the remaining majority of NMSC cases. Whilst metastasis from BCC is extremely rare, metastasis from high-risk SCC may be fatal. In this article, we review the aetiology, diagnosis and management of NMSC.

Methyl-aminolevulinate photodynamic therapy for the treatment of erythroplasia of Queyrat in 23 patients

Erythroplasia of Queyrat (EQ) is an intraepithelial squamous cell carcinoma localized on the mucosal or transitional surfaces. Standard therapy usually consists of the surgical removal of the cancer. The use of non-invasive alternative procedures, such as photodynamic therapy (PDT), has been considered for the treatment of EQ, although only a few reports regarding isolated cases or small series exist. We describe our cumulative experience with PDT, using topical methyl-aminolevulinate (MAL), for the management of 23 male patients with EQ of the glans penis and/or prepuce. Patients underwent two consecutive weekly MAL-PDT sessions, with the second session postponed in seven patients because of an excessive local reaction. Nineteen patients obtained a complete clinical remission without any sign of recurrence over an average post-treatment period of 18 months (range, 8-30 months). Cosmetic outcome was excellent in most patients, while dyschromic changes occurred in four cases. All patients experienced transient local adverse reactions and 22 of them reported severe or very severe symptoms during the session.