The efficacy of photodynamic therapy in the treatment of oral squamous cell carcinoma: a meta-analysis

Effectiveness of photodynamic therapy on treatment response and survival in patients with recurrent oral squamous cell carcinoma: A systematic review

BACKGROUND

This systematic review assessed the effectiveness of photodynamic therapy (PDT) in patients with recurrent oral squamous cell carcinoma (OSCC).

METHODS

Clinical studies on recurrent OSCC treated with PDT alone were included. Combined treatment strategies were excluded. The search was performed on Medline/Pubmed, Cochrane Library, Embase, Web of Science and ClinicalTrials.gov, manual search, and grey literature.

RESULTS

The eleven included studies were observational. The risk of bias and methodological quality were evaluated using the Newcastle-Ottawa Quality Assessment Scale. The studies reported the use of hematoporphyrin derivative, PhotofrinⓇ, FoscanⓇ and 5-aminolevulinic acid. Data on treatment response and survival was collected. Secondarily, postoperative courses and patient's quality of life/acceptance were reported whenever available. PhotofrinⓇ and FoscanⓇ were the most used photosensitisers, with more complete responses. Lesions responding less favourably were on posterior regions or deep-seated in the tissue.

CONCLUSIONS

Although treatment response differs between treatment protocols, PDT stands as a viable treatment option to be considered, as it can achieve therapeutic results and disease-free, long-lasting periods. Partial treatment responses may be of interest when achieving eligibility for other treatment strategies. Despite this study's limitations, which considered four photosensitisers, PhotofrinⓇ was the most used but more recent photosensitisers like FoscanⓇ have greater chemical stability, tissue penetration, and may be more efficacious on recurrent OSCC.

Differences in the response of normal oral mucosa, oral leukoplakia, oral squamous cell carcinoma-derived mesenchymal stem cells, and epithelial cells to photodynamic therapy

OBJECTIVE

The objective of this study is to investigate the variances in transcriptome gene expression of normal oral mucosa-derived mesenchymal stem cell (OM-MSC), oral leukoplakia-derived MSC (OLK-MSC) and oral squamous cell carcinoma-derived MSC(OSCC-MSC). as Additionally, the study aims to compare the in vitro proliferation, migration, invasion ability, and response to photodynamic therapy (PDT) of these three MSC, HOK, DOK, leuk1, and Cal27 cell lines.

METHODS

HOK, DOK, leuk1, Cal27 cells were cultured in vitro. 3 MSC cells were obtained from OM, OLK, OSCC tissue (n = 3) and identified through flow cytometry. They were also cultured in vitro for osteogenic and lipogenic-induced differentiation. Based on the Illumina HiSeq high-throughput sequencing platform, OM-MSC, OLK-MSC, OSCC-MSC (n = 3) were subjected to transcriptome sequencing, functional annotation, and enrichment analysis of differentially expressed genes and related genes. CCK8 assay, wound healing assay, and transwell assay were performed to compare the proliferation, migration, and invasion of the seven types of cells. The 7 cells were incubated with 0, 0.125 mM, 0.25 mM, 0.5 mM, 1 mM, and 2 mM of the photosensitizer (5-aminolevulinic acid, 5-ALA) in vitro. Subsequently, they were irradiated with a 150 mM, 635 nm laser for 1 min, and the cell activity was detected using the CCK8 assay after 24 h. The mitochondrial changes in the 7 cells before and after the treatment of PDT were detected using the JC-10 probe, and the changes in ATP content were measured before and after the PDT treatment.

RESULTS

OM-MSC, OLK-MSC, and OSCC-MSC expressed positive MSC surface markers. After osteogenic and lipogenic-induced differentiation culture, stained calcium nodules and lipid droplets were visible, meeting the identification criteria of MSC. Pathway enrichment analysis revealed that the differentially expressed genes (DEGs) of OSCC-MSC compared to OLK-MSC were primarily associated with the PI3K-Akt signaling pathway and tumor-related pathways. OSCC-MSC exhibited stronger migratory and invasive abilities compared to Cal27. The IC50 values required for OM, OLK, and OSCC-derived MSC were lower than those required for epithelial cells treated with PDT, which were 1.396 mM, 0.9063 mM, and 2.924 mM, respectively. Cell membrane and mitochondrial disruption were observed in seven types of cells after 24 h of PDT treatment. However, HOK, DOK, leuk1, and Cal27 cells had an ATP content increased.

CONCLUSIONS

OLK, OSCC epithelial cells require higher concentrations of 5-ALA for PDT treatment than MSC of the same tissue origin. The concentration of 5-ALA required increases with increasing cell malignancy. Differences in the response of epithelial cells and MSC to PDT treatment may have varying impacts on OLK recurrence and malignancy.

Photodynamic Therapy for Eye, Ear, Laryngeal Area, and Nasal and Oral Cavity Diseases: A Review

Photodynamic therapy (PDT) has emerged as a promising modality for the treatment of various diseases. This non-invasive approach utilizes photosensitizing agents and light to selectively target and destroy abnormal cells, providing a valuable alternative to traditional treatments. Research studies have explored the application of PDT in different areas of the head. Research is focusing on a growing number of new developments and treatments for cancer. One of these methods is PDT. Photodynamic therapy is now a revolutionary, progressive method of cancer therapy. A very important feature of PDT is that cells cannot become immune to singlet oxygen. With this therapy, patients can avoid lengthy and costly surgeries. PDT therapy is referred to as a safe and highly selective therapy. These studies collectively highlight the potential of PDT as a valuable therapeutic option in treating the head area. As research in this field progresses, PDT may become increasingly integrated into the clinical management of these conditions, offering a balance between effectiveness and minimal invasiveness.

Meta analysis of the second course of radiotherapy for recurrent esophageal cancer1

BACKGROUND

How to improve efficacy and reduce side effects in treating recurrent esophageal cancer by applying the second course of radiotherapy alone and its combination with chemotherapy has been attracting broad research interest.

OBJECTIVE

This review paper aims to systematically evaluate efficacy and side effects of applying the second course of anterograde radiotherapy alone and its combination with chemotherapy in treating recurrent esophageal cancer.

METHODS

First, the relevant research papers are retrieved from PubMed, CNKI and Wanfang databases. Next, Redman 5.3 software is used to calculate the relative risk and 95% confidence interval to evaluate the efficacy and adverse reactions of applying the single-stage radiotherapy with and without combining single/multi dose chemotherapy to treat recurrent esophageal cancer. Then, a meta data analysis is applied to examine the effectiveness and side effects of radiation alone and re-course radiotherapy plus chemotherapy in treating esophageal cancer recurrence after the first radiotherapy.

RESULTS

Fifteen papers are retrieved, which included 956 patients. Among them, 476 patients received radiotherapy combined with single drug/multi drug chemotherapy (observation) and others received only radiotherapy (control). Data analysis results show that the incidence of radiation induced lung injury and bone marrow suppression is high in the observation group. Subgroup analysis also shows the higher effective rate or one-year overall survival rate of patients treated with the second course radiotherapy combined with single drug chemotherapy.

CONCLUSION

The meta-analysis result demonstrates that combining the second course of radiotherapy with single-drug chemotherapy has advantages in treating recurrent esophageal cancer with the manageable side effects. However, due to insufficient data, it is not possible to conduct the further subgroup analysis comparing the side effects of restorative radiation with the combined chemotherapy using between a single drug and multiple drugs.

Recent Studies in Photodynamic Therapy for Cancer Treatment: From Basic Research to Clinical Trials

Photodynamic therapy (PDT) is an emerging and less invasive treatment modality for various types of cancer. This review provides an overview of recent trends in PDT research, ranging from basic research to ongoing clinical trials, focusing on different cancer types. Lung cancer, head and neck cancer, non-melanoma skin cancer, prostate cancer, and breast cancer are discussed in this context. In lung cancer, porfimer sodium, chlorin e6, and verteporfin have shown promising results in preclinical studies and clinical trials. For head and neck cancer, PDT has demonstrated effectiveness as an adjuvant treatment after surgery. PDT with temoporfin, redaporfin, photochlor, and IR700 shows potential in early stage larynx cancer and recurrent head and neck carcinoma. Non-melanoma skin cancer has been effectively treated with PDT using methyl aminolevulinate and 5-aminolevulinic acid. In prostate cancer and breast cancer, PDT research is focused on developing targeted photosensitizers to improve tumor-specific uptake and treatment response. In conclusion, PDT continues to evolve as a promising cancer treatment strategy, with ongoing research spanning from fundamental investigations to clinical trials, exploring various photosensitizers and treatment combinations. This review sheds light on the recent advancements in PDT for cancer therapy and highlights its potential for personalized and targeted treatments.

Revisiting the evidence of photodynamic therapy for oral potentially malignant disorders and oral squamous cell carcinoma: an overview of systematic reviews

BACKGROUND

This study summarized the available evidence about the use of photodynamic therapy (PDT) for the management of oral potentially malignant disorders (OPMD) and oral squamous cell carcinoma (OSCC).

METHODS

An overview of systematic reviews was undertaken based on the 2020 PRISMA statement. Electronic searches were performed in five databases. Studies published up to November 2022 were included. Risk of bias was assessed with the AMSTAR 2 tool.

RESULTS

A total of 30 studies enrolling 9,245 individuals with OPMD (n=7,487) or OSCC (n=1,758) met the selection criteria. All studies examined the efficacy and/or safety of PDT. OPMD were investigated individually in 82.8% of the studies, the most common being oral lichen planus and actinic cheilitis. OSCC was addressed separately in 10.3% of the studies, while only 6.9% evaluated both OPMD and OSCC. Fourteen different types of photosensitizers were described. PDT was used according to the following setting parameters: 417-670 nm, 10-500 mW/cm², 1.5-200 J/cm², and 0.5-143 minutes. Regarding OPMD, leukoerythroplakia showed the best response rates, while oral lichen planus presented a partial or no response in nearly 75% of documented cases. A complete response was observed in 85.9% of OSCC cases, while 14.1% had no resolution.

CONCLUSION

Overall, the response to PDT depended on the type of OPMD/OSCC and the parameters used. Although PDT is an emerging candidate for the treatment of OPMD and OSCC, there is heterogeneity of the methodologies used and the clinical data obtained, particularly regarding the follow-up period.

Photodynamic therapy in oral cancer: a review of clinical studies

A significant mortality rate is associated with oral cancer, particularly in cases of late-stage diagnosis. Since the last decades, oral cancer survival rates have only gradually improved despite advances in treatment. This poor success rate is mainly due to the development of secondary tumors, local recurrence, and regional failure. Invasive treatments frequently have a negative impact on the aesthetic and functional outcomes of survivors. Novel approaches are thus needed to manage this deadly disease in light of these statistics. In photodynamic therapy (PDT), a light-sensitive medication called a photosensitizer is given first, followed by exposure to light of the proper wavelength that matches the absorbance band of the photosensitizer. The tissue oxygen-induced cytotoxic free radicals kill tumor cells directly, harm the microvascular structure, and cause inflammatory reactions at the targeted sites. In the case of early lesions, PDT can be used as a stand-alone therapy, and in the case of advanced lesions, it can be used as adjuvant therapy. The current review article discussed the uses of PDT in oral cancer therapy based on recent advances in this field.

Assessment of the methylene blue mediated photodynamic therapy on BCL2 and BAX genes expression at mRNA level and apoptosis of head and neck squamous cell carcinoma cell line

Aim: This study aimed to assess the effect of photodynamic therapy (PDT) on apoptosis of head and neck squamous cell carcinoma (HNSCC) cells by flow cytometry and evaluating BAX and BCL2 genes expression.

Materials and methods: In this in vitro study, human HNSCC cell line (HN5; NCBI. C196) was used and after cell culture, they were divided into four groups: controls (group C), cells irradiated by a diode laser with a wavelength of 660 nm, 150 mW power, and 45 J/cm2 energy density (group L), cells treated by methylene blue (group MB), and cells treated using PDT (group MB plus L). The RNA was then extracted and subjected to quantitative reverse transcription polymerase chain reaction (qRT-PCR) to assess BCL2 and BAX genes expression. Flow cytometry analysis was performed to assess apoptosis. Data were analysed using ANOVA.

Results: PDT caused significant down-regulation of BCL2 (p<0.001) and significant overexpression of BAX (p<0.05) and PDT induced apoptosis HNSCC cell line. Changes in expression of these genes were not significant in other groups (p>0.05).

Conclusions: Considering the down-regulation of BCL2 and overexpression of BAX after PDT using a 660-nm diode laser and MB with 3.2 µg/mL concentration and flow cytometry results, it is suggested that this modality can be introduced for induction of apoptosis in the HNSCC cell line.

Lasers in Live Cell Microscopy

Due to their unique properties—coherent radiation, diffraction limited focusing, low spectral bandwidth and in many cases short light pulses—lasers play an increasing role in live cell microscopy. Lasers are indispensable tools in 3D microscopy, e.g., confocal, light sheet or total internal reflection microscopy, as well as in super-resolution microscopy using wide-field or confocal methods. Further techniques, e.g., spectral imaging or fluorescence lifetime imaging (FLIM) often depend on the well-defined spectral or temporal properties of lasers. Furthermore, laser microbeams are used increasingly for optical tweezers or micromanipulation of cells. Three exemplary laser applications in live cell biology are outlined. They include fluorescence diagnosis, in particular in combination with Förster Resonance Energy Transfer (FRET), photodynamic therapy as well as laser-assisted optoporation, and demonstrate the potential of lasers in cell biology and—more generally—in biomedicine.

Photodynamic therapy for squamous cell carcinoma of the head and neck: narrative review focusing on photosensitizers

This narrative review aimed to evaluate the effectiveness of PDT in early or advanced squamous cell carcinoma of the head and neck (SCCHN). Scopus, MEDLINE/PubMed, and Embase were searched electronically following the PRISMA protocol. Quality assessment was performed according to JBI, NIH, and AMSTAR protocols. The main outcomes evaluated were treatment response, recurrence, survival, and adverse effects. A total of 49 articles met the search criteria: 43 case series, two cohort studies, two prospective before-after clinical trials, one systematic review, and one meta-analysis. Data from 2121 SCCHN patients were included. The response to PDT was variable according to the type of photosensitizer, tumor location, and tumor stage. In general, higher complete responses rated were observed in T1/T2 SCCHN, mainly with mTHPC-mediated PDT. With regard to T3/T4 or advanced SCCHN tumors, there is no compelling evidence suggesting the effectiveness of PDT. Any adverse effects reported were well tolerated by patients. The present review suggests that PDT is a promising treatment modality for early-stage SCCHN. Although there are limitations due to the low level of evidence of the included studies, we believe that the present review could help to design robust clinical trials to determine the efficacy of PDT in SCCHN.

The use of topical ALA-photodynamic therapy combined with induction chemotherapy for locally advanced oral squamous cell carcinoma

BACKGROUNDS

Platinum-based induction chemotherapy (ICT) confers benefits in suitable patients with locally advanced head and neck squamous cell carcinoma (HNSCC). Additionally, the application of a proper local approach can not only promote the survival quality and alleviate the suffering, but also improve the resectability in patients with advanced malignant tumor. 5-aminolevulinic acid photodynamic therapy (ALA-PDT) is a promising minimally invasive therapy and has shown good efficacy in the treatment of patients bearing precancerous lesions and oral squamous cell carcinoma (OSCC). The aim of the study was to evaluate the application of topical ALA-PDT synchronized with ICT in locally advanced OSCC.

PATIENTS AND METHODS

This study described the application of topical ALA-PDT combined with TPF (docetaxel, cisplatin, and 5-fluorouracil) ICT in eleven patients treated due to locally advanced in the oral cavity. Patients qualified for this type of local treatment had cancerous lesions located on the surface of the gum or oral mucosa. The efficacy was evaluated based on the clinical response and complications of the patients.

RESULTS

All patients were treated with four courses (bi-weekly) of ALA-PDT with three courses of TPF containing ICT. After treatment, the overall response rate was 90.9%. Then ten patients with surgery experienced radical surgery alone or combined with radiotherapy except a patient with serious heart condition. In the follow-up period of 26-43 months (median duration of 34.1 months), no local recurrence was observed in cases. Only one patient (9.1%) died of unrelated myocardial infarction.

CONCLUSION

Topical ALA-PDT proved to be a safe treatment in OSCC patients with locally advanced sites, which could be an appropriate addition to ICT. Despite the short observation period and small sample size, it seems justified to conduct prospective studies for the evaluation of the efficacy and safety of topical ALA-PDT synchronized with ICT followed by surgery.

Possibilities of photodynamic therapy in the treatment of malignant tumors of the oral cavity

Oral mucosa cancer is a common disease with relatively low survival rates. The standard for the treatment of malignant neoplasms (MNO) of the oral mucosa is the surgical method, chemotherapy and / or radiation therapy. With the introduction of modern protocols and the improvement of current treatment methods, the increase in survival is insignificant due to the development of local and distant relapses, the appearance of simultaneous tumors of the oral cavity. Cosmetic and functional results in patients who have undergone complex treatment for oral cancer are often unsatisfactory. There is an obvious need to develop new approaches to treating patients with cancer of the oral mucosa. Photodynamic therapy (PDT) has similar properties. With the development of endoscopic and fiber-optic equipment, the fields of PDT application have significantly expanded. Foci in the oral cavity and oropharynx became available for PDT. The early stages of oral mucosal cancer are optimal for PDT because large surface defects can be treated with minimal complications. Preservation of subepithelial and collagen structures, which is typical for PDT, promotes healing without the formation of scar processes, thereby achieving an ideal cosmetic and functional effect. The use of PDT in the treatment of oral cavity cancer is not limited only to the initial stages in an independent version. It is possible to use PDT in combination with surgical and radiation treatment. In case of massive tumor processes, PDT is used for palliative purposes. The influence of the adaptive immune response under the influence of PDT is being studied.

Perspectives on interstitial photodynamic therapy for malignant tumors

SIGNIFICANCE

Despite remarkable advances in the core modalities used in combating cancer, malignant diseases remain the second largest cause of death globally. Interstitial photodynamic therapy (IPDT) has emerged as an alternative approach for the treatment of solid tumors.

AIM

The aim of our study is to outline the advancements in IPDT in recent years and provide our vision for the inclusion of IPDT in standard-of-care (SoC) treatment guidelines of specific malignant diseases.

APPROACH

First, the SoC treatment for solid tumors is described, and the attractive properties of IPDT are presented. Second, the application of IPDT for selected types of tumors is discussed. Finally, future opportunities are considered.

RESULTS

Strong research efforts in academic, clinical, and industrial settings have led to significant improvements in the current implementation of IPDT, and these studies have demonstrated the unique advantages of this modality for the treatment of solid tumors. It is envisioned that further randomized prospective clinical trials and treatment optimization will enable a wide acceptance of IPDT in the clinical community and inclusion in SoC guidelines for well-defined clinical indications.

CONCLUSIONS

The minimally invasive nature of this treatment modality combined with the relatively mild side effects makes IPDT a compelling alternative option for treatment in a number of clinical applications. The adaptability of this technique provides many opportunities to both optimize and personalize the treatment.

Insight into theranostic nanovesicles prepared by thin lipid hydration and microfluidic method

Liposomes are phospholipid-based self-assembled nanoparticles. Various components can be solubilized in the lipid bilayer, encapsulated in the aqueous core or attached to the surface, making liposomes attractive platforms for multimodality functionalization. Here we describe theranostic liposomes delivering a magnetic resonance contrast agent (lipid derivative of gadopentetic acid) and a hydrophobic photosensitizer (zinc phthalocyanine, ZnPc) for photodynamic therapy of cancer. For the first time, this theranostic system was prepared by the microfluidic method. Analogous formulations were produced by thin lipid film hydration (TLH) with down-sizing performed by extrusion for comparison purposes. We demonstrated double the loading capacity of ZnPc into liposomes made by microfluidics compared to TLH/extrusion. Microfluidics resulted in the theranostic nanoliposomes characterized by sizes =2.5x smaller than vesicles prepared by TLH/extrusion. Increased relaxivity was observed for liposomes manufactured by microfluidics compared to TLH, despite a slightly lower Gd chelate recovery. We attributed the improved relaxation to the increased surface area/volume ratio of vesicles and decreased phosphatidylcholine/ZnPc molar ratio, which affected water molecules' diffusion through the liposomal membrane. Finally, we showed photodynamic efficacy of ZnPc loaded into theranostic liposomes in head and neck cancer model, resulting in IC₅₀ of 0.22 - 0.61 μM, depending on the formulation and cell line used. We demonstrate microfluidics' feasibility to be used for theranostic liposome manufacturing and co-entrapment of therapeutic and imaging components in a single-step process with a high yield.

5-Aminolevulinic acid photodynamic therapy for early-stage lip squamous cell carcinoma

BACKGROUND

Squamous cell carcinoma (SCC) of the lip removed by surgery may cause lip dysfunction and scar. ALA-PDT (5-Aminolevulinic acid photodynamic therapy) is a minimally invasive treatment for superficial SCC in situ. However, few studies reported the use of topical ALA-PDT to manage lip SCC.

METHODS

Between 2015 and 2017, 6 patients with Tis to T2 lip squamous cell carcinoma without evidence of lymph node spread, were treated with topical ALA-PDT at Shanghai Skin Disease Hospital. Clinical responses and side effect were evaluated according to the Response Evaluation Criteria in Solid Tumors (RECIST) at 1 month, 6 months, 12 months and 24 months after ALA-PDT.

RESULTS

All of the 6 patients achieved complete response (CR) by 2-7 sessions of ALA-PDT. There was no relapse during 24 months follow up for 4 patients. Two out of 6 patients relapsed at 10 months and 20 months post PDT but achieved CR again by 1-3 more sessions of PDT. There was no functional or aesthetic problem.

CONCLUSION

Topical 5-Aminolevulinic acid photodynamic could be considered a potential alternative therapeutic option for early-stage lip squamous cell carcinoma without lymph node spread.

Photodynamic Therapy in Orthodontics: A Literature Review

Treatment of malocclusions using fixed orthodontic appliances makes it difficult for patients to perform hygiene procedures. Insufficient removal of bacterial biofilm can cause enamel demineralization, manifesting by visible white spot lesions or periodontal diseases, such as gingivitis periodontitis or gingival hyperplasia. The classic methods of preventing the above problems include, in addition to proper hygiene, ultrasonic scaling, periodontal debridement, and oral rinses based on chlorhexidine. New alternative methods of reducing plaque around brackets are being developed. There is a growing interest among researchers in the possibility of using photodynamic therapy in orthodontics. A literature search for articles corresponding to the topic of this review was performed using the PubMed and Scopus databases and the following keywords: ‘photodynamic therapy’, ‘orthodontics’, and ‘photosensitizer(s)’. Based on the literature review, two main directions of research can be distinguished: clinical research on the use of photodynamic therapy in the prevention of white spot lesions and periodontal diseases, and ex vivo research using a modified orthodontic adhesive by adding photosensitizers to them. Methylene blue is the most frequently used photosensitizer in clinical trials. The effectiveness of antimicrobial photodynamic therapy is mainly compared to the ultrasonic scaler as a single therapy or as an adjunct to the ultrasonic scaler. In their conclusions, the researchers most often emphasize the effectiveness of antimicrobial photodynamic therapy in reducing microbial levels in patients treated with fixed appliances and the possibility of using it as an alternative to routine procedures aimed at maintaining a healthy periodontium. The authors suggest further research on the use of photodynamic therapy to prove the validity of this method in orthodontics. It should also not be forgotten that proper hygiene is the basis for maintaining oral cavity health, and its neglect is a contraindication to orthodontic treatment.

[Progress on photodynamic therapy in oral diseases]

Photodynamic therapy (PDT) has developed rapidly in basic and clinical research, and its therapeutic prospects have received increasing attention. PDT has the advantages of minimally invasive, low toxicity, high selectivity, good reproducibility, protection of appearance and vital organ function, and has become a treatment. With the development of medicine, the field of application of PDT becomes more wildly, and brings a new direction for the treatment of oral diseases. This article reviews the basic principles, treatment elements and research results of PDT in the treatment of oral diseases.

Photodynamic Therapy for Oral Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

To assess the efficacy of photodynamic therapy (PDT) for oral squamous cell carcinoma (OSCC), literature on this topic from Embase, PubMed, and Web of Science were obtained and analyzed. The response and recurrence rates with 95% confidence intervals (CI) were calculated using the DerSimonia–Laird method. The pooled complete response (CR) rate from the included studies was 0.799 (95% CI: 0.708–0.867), while the overall response (OR) rate was 0.967 (95% CI: 0.902–0.989). The recurrence rate (RR) was 0.158 (95% CI: 0.090–0.264). A subgroup analysis of lesion site, photosensitizer, laser type, radiant exposure, and power density revealed no statistically significant differences. In general, PDT is effective for the treatment of early OSCC. Investigations on the influence of PDT on the survival of OSCC patients, optimization of the treatment regimen, and evaluation of response after treatment are still needed.

Traditional Chinese medicine for oral squamous cell carcinoma: A Bayesian network meta-analysis protocol

BACKGROUND

Traditional Chinese medicine is frequently used for malignant tumors in China, but in clinical practice, most practitioners choose appropriate Chinese medicines based on personal experience. In our study, Bayesian network meta-analysis will be used to identify differences in efficacy and safety between diverse traditional Chinese drugs for oral squamous cell carcinoma (OSCC).

METHODS

Relevant randomized controlled trials and prospective controlled clinical trials were searched from Medline, PubMed, Cochrane Library, Google Scholar, Excerpt Medica Database, Web of Science, China National Knowledge Infrastructure, China Scientific Journal Database, Chinese Biomedical Literature Database, and Wanfang Database from their establishment to September 2020. Study selection and data extraction will be performed independently by 2 researchers. Aggregate Data Drug Information System and R software were used for data synthesis. The evidentiary grade of the results will be also evaluated.

RESULTS

The results of this study will be published in a peer-reviewed journal, and provide reliable evidence for different traditional Chinese drugs on OSCC.

CONCLUSIONS

The findings will provide reference for evaluating the efficacy and safety of different traditional Chinese medicine for OSCC, and provide a helpful evidence for clinicians to formulate the best adjuvant treatment strategy for OSCC patients.

TRIAL REGISTRATION NUMBER

INPLASY202090082.

Differential in vitro sensitivity of oral precancerous and squamous cell carcinoma cell lines to 5-aminolevulinic acid-mediated photodynamic therapy

OBJECTIVES

The clinical effect of 5-aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) may be correlated with the degree of dysplasia of cancer tissues, but much is still unknown regarding the differences in its effectiveness, especially in oral cancer and precancerous lesions. The aim of this study is to compare the effects of ALA-PDT on a human oral precancerous cell line (DOK) and an oral squamous cell carcinoma cell line (CAL-27).

METHODS

First, we explored the dose- and time-dependent responses of DOK and CAL-27 cells to ALA-PDT. DOK and CAL-27 cells were incubated with various concentrations of ALA (from 0.25 to 2 mM), followed by PDT using laser irradiation at 635 nm. The resulting photocytotoxicity was assessed in both cell lines using MTT assays. Further, apoptosis was assessed using flow cytometry, reactive oxygen species (ROS) generation was evaluated with 2,7-dichlorofluorescein diacetate (DCFH2-DA), and the response to treatment was examined via RT-qPCR and Western blotting to measure the mRNA and protein expression levels of matrix metallopeptidase 2 (MMP-2) and MMP-9.

RESULTS

ALA-PDT inhibited the proliferation of DOK and CAL-27 cells in a dose- and time-dependent manner. Dose-effect and inhibition-time relationships were also found. The rates of DOK and CAL-27 cell apoptosis when the ALA dose was 1 mM were 30.66 ± 3.10% and 75.40 ± 1.29%, respectively (P < 0.01). Following PDT, compared with DOK cells, the ROS level in CAL-27 cells was significantly increased and was correlated with an increase in the ALA concentration. Mechanistically, both the mRNA and protein expression levels of MMP-2 and MMP-9 were found to be regulated in both cell types after ALA-PDT.

CONCLUSION

ALA-PDT effectively killed DOK and CAL-27 cells in a dose- and time-dependent manner in vitro. However, under the same conditions, the susceptibilities of these cell lines to ALA-PDT were different. Further studies are necessary to confirm whether this difference is present in clinical oral cancer and precancerous lesions.

Treatment of Head and Neck Cancer with Photodynamic Therapy with Redaporfin: A Clinical Case Report

Advanced head and neck squamous cell carcinoma, after locoregional treatment and multiple lines of systemic therapies, represents a great challenge to overcome acquired resistance. The present clinical case illustrates a successful treatment option and is the first to describe the use of photodynamic therapy (PDT) with Redaporfin, followed by immune checkpoint inhibition with an anti-PD1 antibody. This patient presented an extensive tumor in the mouth pavement progressing after surgery, radiotherapy, and multiple lines of systemic treatment. PDT with Redaporfin achieved the destruction of all visible tumor, and the sequential use of an immune checkpoint inhibitor allowed a sustained complete response. This case is an example of the effect of this therapeutic combination and may provide the basis for a new treatment modality.

Photodynamic Therapy Mediated by 5-aminolevulinic Acid Promotes the Upregulation and Modifies the Intracellular Expression of Surveillance Proteins in Oral Squamous Cell Carcinoma

Expression of proteins related to cell surveillance has been described in tumors presenting resistance to photodynamic therapy (PDT). The aim of this study was to verify whether there was upregulation of proteins related to resistance in oral squamous cell carcinoma (OSCC) after PDT. OSCC was chemically induced in rats and treated after one cycle of PDT mediated by 5-aminolevulinic acid (5-ALA-PDT). Immunolabeling of p-NFκB, Bcl-2, survivin, iNOS, p-Akt, p-mTOR and cyclin D1 was performed after the treatment. There was increased expression of Bcl-2 (P = 0.008), iNOS (P = 0.020), p-Akt (P = 0.020) and p-mTOR (P = 0.010) by surviving neoplastic cells after PDT when compared to the control. In conclusion, after one cycle of 5-ALA-mediated PDT, Bcl-2, p-Akt, p-mTOR and iNOS were upregulated in neoplastic cells of OSCC, suggesting an activation of antiapoptosis and cell proliferation pathways. This fact must be considered in the establishment of PDT protocols for OSCC treatment, mainly those in which PDT will be combined with chemotherapy drugs targeted at the studied proteins.

Immune consequences induced by photodynamic therapy in non-melanoma skin cancers: a review

Photodynamic therapy (PDT) is widely used in dermatology to treat precancerous skin lesions and superficial non-melanoma skin cancers (NMSCs), including premalignant actinic keratosis, cutaneous squamous cell carcinoma in situ, and superficial basal cell carcinoma. The long-term cure rates of PDT range from 70 to 90% in NMSC patients, with excellent cosmetic results and good tolerance. However, the mechanism of action of PDT on tumors is complex. PDT not only kills tumor cells directly but also rapidly recruits immune cells to release inflammatory mediators to activate antitumor immunity. PDT-induced tumor death, also called immunogenic cell death, can trigger both innate and adaptive immune response, further enhancing the antitumor effect. For instance, inoculation of tumor cells killed via PDT to animals triggered a stronger antitumor immunity in vivo than tumor cell lysates produced by other treatments. More importantly, many immunotherapy regimens based on the immune effect of PDT have been developed and demonstrated to be a promising therapeutic method for cancer in pre-clinical trials. Therefore, increasing efforts have been undertaken to investigate the immune responses associated with PDT. In the present review, we first introduce the antitumor effect and the associated mechanisms of PDT in cancers. Then, we summarize studies on the immune responses induced by PDT in NMSCs. We also discuss the potential mechanisms underlying the process.

A Review of Photodynamic Therapy for Neoplasms of the Head and Neck

Photodynamic therapy (PDT) involves the use of a phototoxic drug which is activated by low powered laser light to destroy neoplastic cells. Multiple photosensitizers have been studied and tumors have been treated in a variety of head and neck sites over the last 30 years. PDT can effectively treat head and neck tumors, particularly those of the superficial spreading type, and the classic application of this technology has been in the patient with a wide field of dysplastic change and superficial carcinomatosis. Interstitial treatment has been used to treat more invasive cancer. Data is available from case series and institutional experiences, but very little randomized data is available. We review the mechanisms of action, historical development, available data, and current knowledge regarding PDT for the various head and neck subsites, and discuss possible future directions, with an emphasis on clinical application.

Prospects in the Application of Photodynamic Therapy in Oral Cancer and Premalignant Lesions

Oral cancer is a global health burden with significantly poor survival, especially when the diagnosis is at its late stage. Despite advances in current treatment modalities, there has been minimal improvement in survival rates over the last five decades. The development of local recurrence, regional failure, and the formation of second primary tumors accounts for this poor outcome. For survivors, cosmetic and functional compromises resulting from treatment are often devastating. These statistics underscore the need for novel approaches in the management of this deadly disease. Photodynamic therapy (PDT) is a treatment modality that involves administration of a light-sensitive drug, known as a photosensitizer, followed by light irradiation of an appropriate wavelength that corresponds to an absorbance band of the sensitizer. In the presence of tissue oxygen, cytotoxic free radicals that are produced cause direct tumor cell death, damage to the microvasculature, and induction of inflammatory reactions at the target sites. PDT offers a prospective new approach in controlling this disease at its various stages either as a stand-alone therapy for early lesions or as an adjuvant therapy for advanced cases. In this review, we aim to explore the applications of PDT in oral cancer therapy and to present an overview of the recent advances in PDT that can potentially reposition its utility for oral cancer treatment.

Current state and future of photodynamic therapy for the treatment of head and neck squamous cell carcinoma

Photodynamic therapy has shown promise in the treatment of early head and neck squamous cell carcinoma (SCC). In photodynamic therapy (PDT), a light sensitive drug (photosensitizer) and visible light cause cancer cell death by the creation of singlet oxygen and free radicals, inciting an immune response, and vascular collapse. In this paper, we review several studies that demonstrate the effectiveness of PDT in the treatment of early stage SCC of the head and neck, with some showing a similar response rate to surgery. Two cases are presented to illustrate the effectiveness of PDT. Then, new advances are discussed including the discovery of STAT3 crosslinking as a potential biomarker for PDT response and interstitial PDT for locally advanced cancers.

DNA photo-cleaving agents in the far-red to near-infrared range – a review

Ideal photonucleases for clinical applications cleave DNA upon activation with deeply penetrating far-red to near-infrared light.