Photobiomodulation and Cancer: What Is the Truth?

Photobiomodulation is effective in oral lichen planus: A randomized, controlled, double-blind study

OBJECTIVES

To compare the efficacy of photobiomodulation to that of topical clobetasol 0.05% in patients with symptomatic oral lichen planus (OLP).

SUBJECTS

Thirty-four patients with symptomatic OLP were randomly allocated into two groups: (a) the Control group (n = 17), application of topical clobetasol propionate 0.05% three times a day for 30 consecutive days with laser placebo applied twice a week to mask the treatment, and (b) the photobiomodulation group (n = 17), laser application twice a week, totalling 8 sessions, and gel placebo for 30 consecutive days to mask the treatment. Evaluations were performed once a week during treatment and 30, 60 and 90 days after treatment. The following parameters were evaluated: pain, clinical scores, clinical resolution and recurrence rate.

RESULTS

Photobiomodulation and propionate clobetasol 0.05% were able to significantly decrease pain in oral lichen planus patients and improve clinical scores during treatment and follow-up. Both the Control and photobiomodulation groups presented similar clinical resolution and recurrence rates. Most importantly, no difference was observed between treatments during treatment and follow-up.

CONCLUSIONS

These findings indicate that photobiomodulation twice a week is as effective as corticoid therapy in treating oral lichen planus. Moreover, photobiomodulation is a safe and non-invasive therapy with the remarkable advantage of no adverse effects.

Safety and Clinical Impact of a Single Red Light Irradiation on Breast Tumor-Bearing Mice

Low-level light therapy has been used in health care as a therapeutic strategy for different diseases. However, its effects on cancer are controversial. This work evaluated the effects of three energies on breast cancer-bearing mice after a single red light-emitting diode (LED) irradiation. 4T1 cells were inoculated into the mammary fat pad of female BALB/c mice. When tumor volume reached 100 mm³ , animals were irradiated by a LED irradiator (660 ± 11 nm) with energies of 1.2, 3.6, and 6.0 J. Control without irradiation and healthy animals were also evaluated. Mice were monitored regarding tumor volume and total blood count. After euthanasia, their organs were examined. We observed that a single irradiation does not increase tumor volume. All irradiated groups exhibited better clinical conditions than control, which presented a significant decrease in platelet and red blood cell levels compared with healthy mice. The energy of 3.6 J arrested neutrophil-lymphocyte rate besides promoting longer survival and a lower number of metastatic nodules in the lungs. These findings suggest that a single red LED irradiation causes no impact on the course of the disease. Besides, the intermediary dose-effect should be further investigated since it seems to promote better outcomes on breast cancer-bearing mice.

Acute and cumulative benefits of Photobiomodulation for xerostomia: A systematic review and meta-analysis

The objective was to explore the effectiveness of photobiomodulation therapy for treating patients who suffer xerostomia and/or hyposalivation due to the most prevalent clinical diagnoses. We searched PubMed, Scopus, Web of Science, CINAHL and Cochrane Library for randomized or clinical controlled trials published until 31 October 2019. Risk of bias assessment and meta-analysis were conducted using the Cochrane tools. A total of 274 records were retrieved, and 11 met the inclusion criteria. Interventions whose parameters ranged between wavelengths of 790-830 nm (infrared), 30-120 mW of power and an energy density below 30 J/cm-2 were associated with improvements in xerostomia/hyposalivation. As for the assessment of methodological quality, 10 of the 11 articles included had a high risk of overall bias. Only 3 articles provided sufficient information to conduct a meta-analysis for quality of life, compared with placebo in patients with burning mouth syndrome, showing a standardized mean difference between groups from baseline of -0.90 (-1.48; -0.32). The present review and meta-analysis suggest that photobiomodulation therapy is an effective, non-invasive and safe approach in patients with xerostomia. However, despite the potential, it is not possible to reach a reliable consensus on the parameters to be used, and future studies should be conducted by standardizing intervention protocols.

Sunlight and health: shifting the focus from vitamin D3 to photobiomodulation by red and near-infrared light

Both sun exposure and serum vitamin D levels have been associated with lower risks of all-cause mortality and chronic age-related diseases, e.g., cancer, diabetes and cardiovascular disease, in epidemiological studies. These associations have mainly been ascribed to beneficial effects of vitamin D. However, a vast body of randomized controlled trials (RCTs) and Mendelian randomization studies have failed to confirm any major health benefits from vitamin D supplementation. In this review, we present tentative evidence showing that red and near-infrared light, both being present in sunlight, could explain the associations between sunlight exposure and better health status. Body irradiation with red and near-infrared light, usually termed as photobiomodulation (PBM), has demonstrated beneficial effects in animal models of chronic diseases. Beyond this, preliminary evidence from RCTs suggest potential clinical benefit from PBM for chronic diseases. PBM is currently being investigated in many pre-registered clinical trials, results of which will eventually clarify the role of red and near-infrared light in the prevention and treatment of common age-related chronic diseases.

Laser-photobiomodulation on experimental cancer pain model in Walker Tumor-256

CONTEXT

Cancer Pain is considered a common and significant clinical problem in malignant neoplasms, comprising 20% to 50% of all patients with tumor progression. Laser photobiomodulation (L-PBM) has been used in a multitude of pain events, ranging from acute trauma to chronic articular. However, L-PBM has never been tested in cancer pain.

OBJECTIVES

Evaluate hyperalgesia, edema, COX-1, COX-2, IL-10, and Bdkrb1 mRNA in low-level laser irradiated Walker-256 tumor-bearing rats.

METHODS

Rat hind paw injected with Walker Tumor-256 (W-256) and divided into six groups of 6 rats: G1 (control) - W-256 injected, G2- W-256 + Nimesulide, G3- W-256 + 1 J, G4- W-256 + 3 Jand G5- W256 + 6 J. Laser parameters: λ = 660 nm, 3.57 W/cm², Ø = 0.028 cm². Mechanical hyperalgesia was evaluated by Randall-Selitto test. Plethysmography measured edema; mRNA levels of COX-1, COX-2, IL-10, and Bdkrb1were analyzed.

RESULTS

It was found that the W-256 + 1 J group showed a decrease in paw edema, a significant reduction in pain threshold. Higher levels of IL-10 and lower levels of COX-2 and Bdkrb1 were observed.

CONCLUSION

Results suggest that 1 J L-PBM reduced the expression of COX-2 and Bdkrb1 and increasing IL-10 gene expression, promoting analgesia to close levels to nimesulide.

Review on the Cellular Mechanisms of Low-Level Laser Therapy Use in Oncology

Photobiomodulation (PBM) using low-level laser therapy (LLLT) is a treatment that is increasingly used in oncology. Studies reported enhancement of wound healing with reduction in pain, tissue swelling and inflammatory conditions such as radiation dermatitis, oral mucositis, and lymphedema. However, factors such as wavelength, energy density and irradiation frequency influence the cellular mechanisms of LLLT. Moreover, the effects of LLLT vary according to cell types. Thus, controversy arose as a result of poor clinical response reported in some studies that may have used inadequately planned treatment protocols. Since LLLT may enhance tumor cell proliferation, these will also need to be considered before clinical use. This review aims to summarize the current knowledge of the cellular mechanisms of LLLT by considering its effects on cell proliferation, metabolism, angiogenesis, apoptosis and inflammation. With a better understanding of the cellular mechanisms, bridging findings from laboratory studies to clinical application can be improved.

Neuroprotective Properties of Photobiomodulation in Retinal Regeneration in Rats: Perspectives From Interaction Levels

Introduction: Photobiomodulation (PBM) is known as low-level laser (or light) therapy and is applied in different fields of medicine. However, it is required that its molecular and cellular mechanism be investigated. This study aims to assess the neuroprotective properties of PBM in the rat retina. Methods: GSE22818 was downloaded from Gene Expression Omnibus (GEO) and the regulation of the significant differentially expressed genes (DEGs) which are produced by light damage in the rat retina by the pretreatment of PBM application was assessed via network analysis and gene ontology enrichment. Results: The 78 produced DEGs by light-damage in the rat retina were protected via PBM pretreatment action. Among these determined DEGs, 53 individuals were included in the main connected component of the constructed protein-protein interaction (PPI) network. Ccl2, Icam1, Cxcl10, Timp1, and Fos were determined as hub nodes. Eight clusters including 26 regulated biochemical pathways by PBM pretreatment were identified. The critical DEGs based on the action maps were introduced. Conclusion: The finding indicates that PBM treatment protects rat retina against light damage via the prevention of Fos, Ccl2, Icam1, Cxcl10, and Myc dysregulation.

In vitro anti-tumor effect of high-fluence low-power laser light on apoptosis of human colorectal cancer cells

Colorectal cancer is the third most common malignancy all over the world, along with high morbidity and mortality. As a treatment, high-fluence low-power laser irradiation (HF-LPLI) has reported that its biostimulatory activity can suppress or even destruct tumor growth in neoplastic diseases. The aim of the present study is to examine a therapeutic capacity of HF-LPLI for colorectal cancer treatment by using human colon cancer cell (HT29) model. The in vitro cancer cell model was used to analyze the underlying mechanism of laser-induced apoptosis. Laser irradiation was performed five times (once a day for five consecutive days) with 635 nm laser light for 8 and 16 min (fluence = 128 and 256 J/cm²), respectively. The efficiency of the HF-LPLI treatment was evaluated by MTT, fluorescence staining, cell wound healing, and western blot test during the 5-day period. Experiment data showed that HF-LPLI had a dose-dependent stimulating effect on cell viability, migration, and apoptosis of HT29 cells. The inhibition effect of laser treatment at 256 J/cm² on cell viability was statistically significant. Meanwhile, the wound healing and western blot tests also confirmed that HF-LPLI could inhibit cell migration and induce cell apoptosis. The current research results demonstrate that 635 nm HF-LPLI can be an alternative treatment option for colorectal cancer by increasing the expression of caspase-3 and inducing HT29 tumor cell apoptosis through activation of the mitochondrial pathway.

Photobiomodulation Therapy for the Management of Chemotherapy-Induced Peripheral Neuropathy: An Overview

Background: Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of chemotherapy (CT), affecting 68% of patients. Current treatment strategies are based on pharmacological symptom management, but have limited results. Photobiomodulation therapy (PBMT) is a new and emerging therapeutic tool in the supportive care of cancer patients. In this overview, we explore the usability of PBMT for management of CIPN. Objective: To provide a comprehensive overview of management of CIPN with PBMT. Methods: Specific terms, including "Photobiomodulation Therapy," "Drug Therapy," and "Peripheral Nervous System Diseases," were identified for the literature research in PubMed. Results: Three articles were considered eligible for this review. Primary outcome measures were highly variable across the included studies. Conclusions: PBMT might be an effective treatment strategy to manage CIPN, with very encouraging reports from renowned teams, but evidence is limited. More methodologically uniform research (mainly regarding the parameters of PBMT) is needed to support the use of PBMT for this indication.

Anti-cancer effect of gallic acid in presence of low level laser irradiation: ROS production and induction of apoptosis and ferroptosis

BACKGROUND

There are different treatments for breast cancer and melanoma that mostly have some side effects. One of the therapeutic strategies is the use of natural components. Phenol components are a class of antioxidants in plants that have many biological functions like anticancer effects. Gallic acid (GA) is a natural polyhydroxy phenolic compound and commonly found in various foods. In the present study, GA effects alone and in combination with low-level laser irradiation on human dermal fibroblast cell line (HDF), human non-tumorigenic breast epithelial cell line (MCF10A), breast cancer cell line (MDA-MB-231) and melanoma cancer cell line (A375) was under the investigation.

METHODS

The normal and cancerous cell lines were exposed to 660 nm low-level laser with 3 J/cm2 for 90 s. Then, the cells were treated with different concentrations of GA for 24 h. In another study, the cell lines firstly were treated with GA and then exposed to low-level laser irradiation. The effects of GA and low-level laser on cell survival and apoptosis were examined using MTT assay, light microscopy, ROS production assay, fluorescence microscopy (AO/EB double staining) and flow cytometry.

RESULTS

The results showed that pre-treatment with low-level laser and then GA reduced the survival of breast cancer cells and melanoma more than the first treatment with GA and then low-level laser irradiation. Our findings showed that ROS production in cells treated with both low-level laser and GA was more than the cells treated with GA alone. The apoptosis and ferroptosis assays confirmed the MTT results which combination treatment with low-level laser and then GA increase the cell death probably via apoptosis and ferroptosis cell death mechanisms compared to GA alone.

CONCLUSIONS

This study suggests that low-level laser irradiation alone is not able to cause death in human normal and cancerous cells. Preirradiation followed by GA treatment did not change the cell viability in human normal significantly but reduces the cell survival of cancer cells more than GA alone.

Photobiomodulation and photodynamic therapy for the treatment of oral mucositis in patients with cancer

BACKGROUND

Photobiomodulation therapy (PBM-T) can penetrate soft tissues and exert analgesic and healing effects, and is thus a promising alternative for prevention and treatment of oral mucositis (OM). The aim of this study was to evaluate the efficacy of PBM-T, alone or combined with photodynamic therapy (PDT), for treatment of OM in cancer patients.

METHODS

Fifty-six patients were recruited from the Oncology Department of a teaching hospital. Patients underwent grading of OM and were divided into two groups (n = 28 each): PBM-T and PBM-T + PDT. In the PBM-T group, low-level laser was applied to 61 points in the oral cavity, once weekly for 4 weeks (wavelength 660 nm, power 100 mW, energy density 142 J/cm², spot energy 4 J, irradiation time 40 s). In the PBM-T + PDT group, in addition to PBM-T as described above, patients rinsed with 20 ml of photosensitizing mouthwash (curcumin 1.5 g/L) and the oral cavity was irradiated with a blue (468 nm) LED for 5 min.

RESULTS

Significant reductions in OM grade were observed after application of PBM-T or PBM-T + PDT (p < 0.0001). PBM-T + PDT resulted in a shorter time to resolution of lesions compared to PBM-T alone (p = 0.0005).

CONCLUSIONS

PBM-T, alone or combined with PDT, can be used for the treatment of OM. PDT + PBM-T in particular accelerated the OM healing process, reducing time to lesion remission from 15 to 11 days.

Cellular transformations in near-infrared light-induced apoptosis in cancer cells revealed by label-free CARS imaging

Photobiomodulation (PBM) involves light to activate cellular signaling pathways leading to cell proliferation or death. In this work, fluorescence and Coherent anti-Stokes Raman Scattering (CARS) imaging techniques were applied to assess apoptosis in human cervical cancer cells (HeLa) induced by near infrared (NIR) laser light (808 nm). Using the Caspase 3/7 fluorescent probe to identify apoptotic cells, we found that the pro-apoptotic effect is significantly dependent of irradiation dose. The highest apoptosis rate was noted for the lower irradiation doses, that is, 0.3 J/cm² (~58%) and 3 J/cm² (~28%). The impact of light doses on proteins/lipids intracellular metabolism and distribution was evaluated using CARS imaging, which revealed apoptosis-associated reorganization of nuclear proteins and cytoplasmic lipids after irradiation with 0.3 J/cm² . Doses of NIR light causing apoptosis (0.3, 3 and 30 J/cm² ) induced a gradual increase in the nuclear protein level over time, in contrast to proteins in cells non-irradiated and irradiated with 10 J/cm² . Furthermore, irradiation of the cells with the 0.3 J/cm² dose resulted in lipid droplets (LDs) accumulation, which was apparently caused by an increase in reactive oxygen species (ROS) generation. We suggest that PBM induced apoptosis could be caused by the ability of NIR light to trigger excessive LDs formation which, in turn, induces cellular cytotoxicity.

Photobiomodulation Therapy in the Treatment of Oral Mucositis, Dysphagia, Oral Dryness, Taste Alteration, and Burning Mouth Sensation Due to Cancer Therapy: A Case Series

Oral complications of cancer therapy, such as oral dryness, dysphagia, and taste alteration, are associated with a negative impact in the quality of life of the patients. Few supportive care measures are available for such complications. This case series reveals the effectiveness of the photobiomodulation (PBM) therapy when used in a specific protocol and parameters, in the management of oral complications related to cancer therapy. Dysphagia was measured using the functional outcome swallowing scale for staging oropharyngeal dysphagia (FOSS). Oral mucositis was measured according to the National Cancer Institute scale. The quantity of the whole resting and stimulated saliva was measured in order to assess the oral dryness. In addition, the taste alteration was measured according to a protocol suggested by the International Standards organization (ISO). Sensation of burning mouth was measured using a visual analogue scale. These measurements were made before treatment, during, and at the end of the treatment. Diode laser 635 nm was used in 3 J/cm2. Five sessions interleaved with 24 h breaks were conducted for the dysphagia and oral dryness, and 10 sessions were conducted for the taste alteration and burning mouth sensation. Regardless of the limitations of this case series, PBM can be considered safe, time saving, and a promising approach for the management of the oral complications due to cancer therapy and the quality of life of cancer patients.

The Rationale for Photobiomodulation Therapy of Vaginal Tissue for Treatment of Genitourinary Syndrome of Menopause: An Analysis of Its Mechanism of Action, and Current Clinical Outcomes

Objective: Light, particularly in the visible to far-infrared spectrum, has been applied to the female genital tract with lasers and other devices for nearly 50 years. These have included procedures on both normal and neoplastic tissues, management of condylomata, endometriosis, and menometrorrhagia, and, more recently, a number of fractional laser devices have been applied for the management of genitourinary syndrome of menopause (GSM) and stress urinary incontinence (SUI), and to achieve so-called vaginal rejuvenation. Photobiomodulation therapy (PBMT) has been proposed as an alternative for use in managing GSM and SUI.

Methods: This article reviews the biological basis, symptoms, and management of GSM, and investigates the current status and rationale for the use of PBMT.

Results and conclusions: Based on the preliminary evidence available, PBMT is safe and appears to be efficacious in treating GSM.

Low-level laser therapy in treatment of chemoradiotherapy-induced mucositis in head and neck cancer: results of a randomised, triple blind, multicentre phase III trial

Background

Low-level laser therapy (LLLT) also called Photobiomodulation therapy (PBMT) could reduce oral mucositis (OM) incidence and severity in head and neck cancer patients treated by chemoradiotherapy, however randomised data about efficacy and safety are missing with curative dose 4 J/cm².

Methods

This phase III trial was conducted in patients with oral cavity, or oro/hypopharyngeal cancers (stage III or IV). Patients were treated by lasertherapy on OM lesions grade ≥ 2 (4 J/cm² or placebo), during chemoradiotherapy and until recovery. Severity of OM (incidence and duration of grades ≥3) was used as primary endpoint and blindly assessed.

Results

Among 97 randomised patients, 83 patients (85.6%) could be assessed finally (erroneous inclusions, chemoradiotherapy interruptions) and 32 patients had no lasertherapy because of unreachable OM lesions. Randomisation and population characteristics (sex ratio, age, chemoradiotherapy procedures, toxicities incidence) were still comparable between the two LLLT/PBMT groups. An acute OM (grade ≥ 3) was observed in 41 patients (49.4%): 23 patients (54.8%) of the active laser group versus 18 (43.9%) in the control group (modified intend to treat, p = 0.32). Median time before occurrence of OM ≥ grade 3 in half of the patients was 8 weeks in active laser group (vs. 9 weeks in control group). However, 95% of patients exhibited a very good tolerance of LLLT/PBMT.

Conclusions

This study assessed LLLT/PBMT according to the Multinational Association of Supportive care in Cancer recommendations but lacked power. LLLT/PBMT was well tolerated with a good safety profile, which promotes its use in clinical routine for severe OM treatment.

Trial registration

ClinicalTrials.gov Identifier: NCT01772706.

Title: Laser Mucite ORL: Effectiveness of Laser Therapy for Mucositis Induced by a Radio-chemotherapy in Head and Neck Cancer (LaserMucite).

Study Start Date: October 2008.

Primary Completion Date: October 2016.

Responsible Party: Institut de Cancérologie de l’Ouest – Paul Papin.

Principal Investigator: Eric Jadaud, M.D., Institut de Cancérologie de l’Ouest – Paul Papin.

Funding: French Ministry of Health, French national funding scheme (PHRC 2008).

Examining tumor modulating effects of photobiomodulation therapy on head and neck squamous cell carcinomas

The aim of the present systematic review was to analyze studies that investigated the effects of photobiomodulation therapy on head and neck squamous cell carcinoma cells.