Kinetics of response to long-term treatment combining pentoxifylline and tocopherol in patients with superficial radiation-induced fibrosis

Long Noncoding VIM-AS1: Biomarker of Breast Fibrosis Susceptibility After Radiation Therapy and Promoter of Transforming Growth Factor Beta1-Driven Fibrosis

PURPOSE

Fibrosis is a common late complication of radiation therapy. Molecular dysregulations leading to fibrosis have been characterized for the coding part of the genome, notably those involving the TGFB1 gene network. However, because a large part of the human genome encodes RNA transcripts that are not translated into proteins, exploring the involvement of the noncoding part of the genome in fibrosis susceptibility and development was the aim of this work.

METHODS AND MATERIALS

Breast cancer patients having or not having developed severe breast fibrosis after radiation therapy were retrospectively selected from the COPERNIC collection. Exome sequencing and RNA-seq transcriptomic profiling were performed on 19 primary dermal fibroblast strains isolated from the patients' nonirradiated skin. Functional experiments were based on fibrogenic induction by transforming growth factor-Beta1 (TGFB1) and gene knockdown in healthy donor fibroblasts.

RESULTS

Coding and noncoding transcriptomes discriminated fibrosis from nonfibrosis conditions, and a signature of breast fibrosis susceptibility comprising 15 long noncoding RNAs (lncRNAs) was identified. A hazard ratio validation showed that the lncRNA vimentin antisense long noncoding RNA 1 (VIM-AS1) was the best biomarker associated with fibrosis risk. This lncRNA has not been previously associated with any fibrotic disorder, but we found it upregulated in data sets from cardiac fibrosis and scleroderma, suggesting a general role in tissue fibrosis. Functional experiments demonstrated a profibrotic action of VIM-AS1 because its knockdown reduced myofibroblast activation, collagen matrix production, and dermal organoid contraction. RNA-seq data analysis after VIM-AS1 silencing also pointed out the regulation of replication, cell cycle, and DNA repair. Mechanistically, because VIM-AS1 was found coregulated with the vimentin gene, these data support a profibrotic function of the TGFB1/VIM-AS1/vimentin axis, targeting the dynamics of fibroblast-myofibroblast transition.

CONCLUSIONS

Noncoding RNA analysis can provide specific biomarkers relevant to the prediction of normal tissue responses after radiation therapy, which opens perspectives of next-generation approaches for treatment, in the frame of the recent developments of RNA-based technologies.

AI-assisted models to predict chemotherapy drugs modified with C60 fullerene derivatives

Employing quantitative structure-activity relationship (QSAR)/ quantitative structure-property relationship (QSPR) models, this study explores the application of fullerene derivatives as nanocarriers for breast cancer chemotherapy drugs. Isolated drugs and two drug-fullerene complexes (i.e., drug-pristine C60 fullerene and drug-carboxyfullerene C60-COOH) were investigated with the protein CXCR7 as the molecular docking target. The research involved over 30 drugs and employed Pearson's hard-soft acid-base theory and common QSAR/QSPR descriptors to build predictive models for the docking scores. Energetic descriptors were computed using quantum chemistry at the density functional-based tight binding DFTB3 level. The results indicate that drug-fullerene complexes interact more with CXCR7 than isolated drugs. Specific binding sites were identified, with varying locations for each drug complex. Predictive models, developed using multiple linear regression and IBM Watson artificial intelligence (AI), achieved mean absolute percentage errors below 12%, driven by AI-identified key variables. The predictive models included mainly quantitative descriptors collected from datasets as well as computed ones. In addition, a water-soluble fullerene was used to compare results obtained by DFTB3 with a conventional density functional theory approach. These findings promise to enhance breast cancer chemotherapy by leveraging fullerene-based drug nanocarriers.

Cutaneous Radiation Injuries: REAC/TS Clinical Experience

The Radiation Emergency Assistance Center/Training Site (REAC/TS) is one of the US Department of Energy (DOE)/National Nuclear Security Administration (NNSA) Nuclear Emergency Response Team (NEST) assets and has been responding to radiological incidents since 1976. REAC/TS is in the Oak Ridge Institute for Science and Education (ORISE). A critical part of the REAC/TS mission is to provide emergency response, advice, and consultation on injuries and illnesses caused from ionizing radiation. Fortunately, radiation injuries are not frequent, but when they occur, they are more likely to be cutaneous radiation injuries (CRI) or internal contamination. In this paper, we will review selected cases from the REAC/TS experience in order to illustrate cutaneous patterns of injury and treatment options.

Tissue fibrosis induced by radiotherapy: current understanding of the molecular mechanisms, diagnosis and therapeutic advances

Cancer remains the leading cause of death around the world. In cancer treatment, over 50% of cancer patients receive radiotherapy alone or in multimodal combinations with other therapies. One of the adverse consequences after radiation exposure is the occurrence of radiation-induced tissue fibrosis (RIF), which is characterized by the abnormal activation of myofibroblasts and the excessive accumulation of extracellular matrix. This phenotype can manifest in multiple organs, such as lung, skin, liver and kidney. In-depth studies on the mechanisms of radiation-induced fibrosis have shown that a variety of extracellular signals such as immune cells and abnormal release of cytokines, and intracellular signals such as cGAS/STING, oxidative stress response, metabolic reprogramming and proteasome pathway activation are involved in the activation of myofibroblasts. Tissue fibrosis is extremely harmful to patients' health and requires early diagnosis. In addition to traditional serum markers, histologic and imaging tests, the diagnostic potential of nuclear medicine techniques is emerging. Anti-inflammatory and antioxidant therapies are the traditional treatments for radiation-induced fibrosis. Recently, some promising therapeutic strategies have emerged, such as stem cell therapy and targeted therapies. However, incomplete knowledge of the mechanisms hinders the treatment of this disease. Here, we also highlight the potential mechanistic, diagnostic and therapeutic directions of radiation-induced fibrosis.

Overview of radiotherapy-induced chronic pain in childhood cancer survivors: A narrative review

Radiotherapy is an important aspect of oncological treatment in several childhood cancers. However, radiotherapy is known to have numerous side effects, including detrimental effects on growth, neurocognitive impairment, and the development of secondary malignancies. One less studied long-term side effect of pediatric radiotherapy treatment is chronic pain. While the short-term toxicities of radiotherapy resolve over a few weeks to months, the chronic pain caused by radiotherapy-induced tissue damage can significantly affect children's quality of life. As long-term childhood cancer survivors age into adulthood, they are typically followed up by a wide variety of doctors, not all of whom may be familiar with radiotherapy-induced chronic pain and its management. The aim of this review is to discuss the various common manifestations of radiotherapy-related pain in children, as well as ways to identify and manage these. Common radiotherapy-related side effects leading to chronic pain symptoms include radiation fibrosis, enteritis, dermatitis, lymphedema, neuropathic pain, and effects on bone development. The pathophysiology, evaluation and management of these are briefly summarized in this review. This is followed by an overview of radiotherapy techniques that allow greater sparing of normal tissue, minimizing future painful side effects. Finally, the assessment of pain in children is described, as well as strategies for management, and red flag symptoms that should prompt urgent specialist referral. In conclusion, a good understanding of the long-term side effects of radiotherapy treatment in children is essential for the various medical professionals that follow-up the child in the years after treatment. For young children, the evaluation of pain is in itself a challenge, and effects on growth, development, and learning are crucial. For older children, social and psychological factors become increasingly important. As radiation therapy techniques continue to advance, the spectrum and incidence of chronic pain syndromes may change over time.

Evidence-Based Guidance for Breast Cancer Survivorship

Breast cancer survivorship care includes management of lingering physical symptoms, supports to address the emotional toll exacted by a cancer diagnosis and cancer therapies, monitoring and optimization of cardiac and bone health, general wellness promotion, reproductive health care, surveillance for cancer recurrence, care coordination, and efforts to mitigate health disparities.

A raising dawn of pentoxifylline in management of inflammatory disorders in Covid-19

The existing pandemic viral infection caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) leads to coronavirus disease 2019 (Covid-19). SARS-CoV-2 exploits angiotensin-converting enzyme 2 (ACE2) as an entry-point into affected cells and down-regulation of ACE2 by this virus triggers the release of pro-inflammatory cytokines and up-regulation of angiotensin II. These changes may lead to hypercytokinemia and the development of cytokine storm with the development of acute lung injury and acute respiratory distress syndrome. Different repurposed had been in use in the management of Covid-19, one of these agents is pentoxifylline (PTX) which has anti-inflammatory and antioxidant properties. Therefore, the objective of the present mini-review is to highlight the potential role of PTX in Covid-19 regarding its anti-inflammatory and antioxidant effects. PTX is a non-selective phosphodiesterase inhibitor that increases intracellular cyclic adenosine monophosphate which stimulates protein kinase A and inhibits leukotriene and tumor necrosis factor. PTX has antiviral, anti-inflammatory and immunomodulatory effects, thus it may attenuate SARS-CoV-2-induced hyperinflammation and related complications. As well, PTX can reduce hyper-viscosity and coagulopathy in Covid-19 through increasing red blood cell deformability and inhibition of platelet aggregations. In conclusion, PTX is a non-selective phosphodiesterase drug, that has anti-inflammatory and antioxidant effects thereby can reduce SARS-CoV-2 infection-hyperinflammation and oxidative stress. Besides, PTX improves red blood cells (RBCs) deformability and reduces blood viscosity so can mitigate Covid-19-induced hyper-viscosity and RBCs hyper-aggregation which is linked with the development of coagulopathy. Taken together, PTX seems to be an effective agent against Covid-19 severity.

Gastrointestinal Toxicity of Pelvic Radiotherapy: Are We Letting Women Down?

For all cancers there are four areas of importance: prevention, early diagnosis, optimising therapy and living with and beyond. For women diagnosed with gynaecological cancers, progress in these first three areas has been immense. However, living with and beyond has largely been ignored as a significant issue. As a group, patients treated for gynaecological cancer are more often young and more often suffer the most difficult long-term issues. Despite the growing number of long-term survivors, little has been done to ensure appropriate assessment and treatment of side-effects of cancer therapies, especially when radiotherapy has been used. For many affected patients their symptoms become part of everyday life, 'normality' is adjusted and these changes are tolerated even when severely limiting activities. Data show that even expert clinicians frequently do not appreciate the true impact of these problems and the focus of treatment and of follow-up remains fixed on 5-year survival and cancer recurrence, respectively. Many clinicians are unaware of what experts can do for toxicity and do not know where to refer their patients. However, rapid identification of patients with significant symptoms can lead to earlier diagnosis of treatable pathologies and improvement in patients' quality of life. In addition, the underlying pathophysiology of radiation-induced damage is potentially amenable to disease-modifying therapies. This review focuses on the factors that contribute to patients developing pelvic radiation disease, what can be done to mitigate the toxicity of treatment and highlights the challenges that must be addressed to reduce the gastrointestinal toxicity of pelvic radiotherapy.

Radiation-induced lung injury: current evidence

Chemo-radiotherapy and systemic therapies have proven satisfactory outcomes as standard treatments for various thoracic malignancies; however, adverse pulmonary effects, like pneumonitis, can be life-threatening. Pneumonitis is caused by direct cytotoxic effect, oxidative stress, and immune-mediated injury. Radiotherapy Induced Lung Injury (RILI) encompasses two phases: an early phase known as Radiation Pneumonitis (RP), characterized by acute lung tissue inflammation as a result of exposure to radiation; and a late phase called Radiation Fibrosis (RF), a clinical syndrome that results from chronic pulmonary tissue damage. Currently, diagnoses are made by exclusion using clinical assessment and radiological findings. Pulmonary function tests have constituted a significant step in evaluating lung function status during radiotherapy and useful predictive tools to avoid complications or limit toxicity. Systemic corticosteroids are widely used to treat pneumonitis complications, but its use must be standardized, and consider in the prophylaxis setting given the fatal outcome of this adverse event. This review aims to discuss the clinicopathological features of pneumonitis and provide practical clinical recommendations for prevention, diagnosis, and management.

Protection against chemotherapy- and radiotherapy-induced side effects: A review based on the mechanisms and therapeutic opportunities of phytochemicals

BACKGROUND

Although great achievements have been made in the field of cancer therapy, chemotherapy and radiotherapy remain the mainstay cancer therapeutic modalities. However, they are associated with various side effects, including cardiocytotoxicity, nephrotoxicity, myelosuppression, neurotoxicity, hepatotoxicity, gastrointestinal toxicity, mucositis, and alopecia, which severely affect the quality of life of cancer patients. Plants harbor a great chemical diversity and flexible biological properties that are well-compatible with their use as adjuvant therapy in reducing the side effects of cancer therapy.

PURPOSE

This review aimed to comprehensively summarize the molecular mechanisms by which phytochemicals ameliorate the side effects of cancer therapies and their potential clinical applications.

METHODS

We obtained information from PubMed, Science Direct, Web of Science, and Google scholar, and introduced the molecular mechanisms by which chemotherapeutic drugs and irradiation induce toxic side effects. Accordingly, we summarized the underlying mechanisms of representative phytochemicals in reducing these side effects.

RESULTS

Representative phytochemicals exhibit a great potential in reducing the side effects of chemotherapy and radiotherapy due to their broad range of biological activities, including antioxidation, antimutagenesis, anti-inflammation, myeloprotection, and immunomodulation. However, since a majority of the phytochemicals have only been subjected to preclinical studies, clinical trials are imperative to comprehensively evaluate their therapeutic values.

CONCLUSION

This review highlights that phytochemicals have interesting properties in relieving the side effects of chemotherapy and radiotherapy. Future studies are required to explore the clinical benefits of these phytochemicals for exploitation in chemotherapy and radiotherapy.

Osteonecrosis of the jaw associated with imatinib therapy in myeloproliferative neoplasm: a rare case report

Medication-related osteonecrosis of the jaw (MRONJ) is a relatively infrequent but very well-known adverse effect of bisphosphonates. This rare complication of bisphosphonates is rarest with the use of certain drugs. Tyrosine kinase inhibitors (TKIs), particularly used in renal cell carcinoma or gastrointestinal tumors as a chemotherapeutic agent, can precipitate this particular medical condition of bone when it is associated with either radiation or bisphosphonates, though, monodrug therapy with TKIs rarely causes MRONJ. This article describes a rare case of necrosis of the jawbone in a patient with a myeloproliferative neoplasm who was receiving the TKI imatinib and had no history of bisphosphonate or radiation therapy to head and neck region.

The effect of two phosphodiesterase inhibitors on bone healing in mandibular fractures (animal study in rats)

OBJECTIVES

Despite advances in maxillofacial surgery, impaired bone healing remains a concern for surgical teams. Many studies have evaluated the effects of sildenafil and pentoxifylline on bone healing. However, their effects on healing of bone fractures have not been well investigated. This study aimed to assess the effects of the phosphodiesterase inhibitors sildenafil and pentoxifylline on healing of mandibular fractures in rats.

MATERIALS AND METHODS

A total of 60 rats were randomly divided into six groups of 10. Mandibular fracture was induced in all rats. After the surgical procedure, group C1 received saline, group S1 received 10 mg/kg sildenafil and group P1 received 50 mg/kg pentoxifylline. The rats were sacrificed after 1 week. Groups C4, S4, and P4 received pharmaceutical therapy as in groups C1, S1, and P1 but were sacrificed after 4 weeks. The samples then underwent histological analysis.

RESULTS

The mean rate of bone healing of mandibular fractures in groups S1 and P1 was significantly higher than in group C1 at 1 week (P<0.001). The mean rate of bone healing of mandibular fractures in group P1 was higher than in group S1 at 1 week (P=0.04). The mean rate of bone healing of mandibular fractures in groups S4 (P=0.001) and P4 (P=0.004) was significantly higher than in group C4 at 4 weeks, but no significant difference was noted in the rate of healing between groups P4 and S4 (P=0.53).

CONCLUSION

Sildenafil and pentoxifylline can be used as adjuncts to enhance bone healing in rats.

Bi-directional communication: Conversations between fibroblasts and immune cells in systemic sclerosis

Systemic Sclerosis (SSc) is an autoimmune idiopathic connective tissue disease, characterized by aberrant fibro-proliferative and inflammatory responses, causing fibrosis of multiple organs. In recent years the interactions between innate and adaptive immune cells with resident fibroblasts have been uncovered. Cross-talk between immune and stromal cells mediates activation of stromal cells to myofibroblasts; key cells in the pathophysiology of fibrosis. These cells and their cytokines appear to mediate their effects in both a paracrine and autocrine fashion. This review examines the role of innate and adaptive immune cells in SSc, focusing on recent advances that have illuminated our understanding of ongoing bi-directional communication between immune and stromal cells. Finally, we appraise current and future therapies and how these may be useful in a disease that currently has no specific disease modifying treatment.

Prophylactic treatment with transdermal deferoxamine mitigates radiation-induced skin fibrosis

Radiation therapy can result in pathological fibrosis of healthy soft tissue. The iron chelator deferoxamine (DFO) has been shown to improve skin vascularization when injected into radiated tissue prior to fat grafting. Here, we evaluated whether topical DFO administration using a transdermal drug delivery system prior to and immediately following irradiation (IR) can mitigate the chronic effects of radiation damage to the skin. CD-1 nude immunodeficient mice were split into four experimental groups: (1) IR alone (IR only), (2) DFO treatment for two weeks after recovery from IR (DFO post-IR), (3) DFO prophylaxis with treatment through and post-IR (DFO ppx), or (4) no irradiation or DFO (No IR). Immediately following IR, reactive oxygen species and apoptotic markers were significantly decreased and laser doppler analysis revealed significantly improved skin perfusion in mice receiving prophylactic DFO. Six weeks following IR, mice in the DFO post-IR and DFO ppx groups had improved skin perfusion and increased vascularization. DFO-treated groups also had evidence of reduced dermal thickness and collagen fiber network organization akin to non-irradiated skin. Thus, transdermal delivery of DFO improves tissue perfusion and mitigates chronic radiation-induced skin fibrosis, highlighting a potential role for DFO in the treatment of oncological patients.

The effects of pentoxifylline and tocopherol in jaw osteomyelitis

Objectives

Pentoxifylline (PTX) is a methylxanthine derivative that has been implicated in the pathogenesis of peripheral vessel disease and intermittent lameness. The purpose of this study was to investigate the effect of PTX and tocopherol in patients diagnosed with osteoradionecrosis (ORN), bisphosphonate-related osteonecrosis of the jaw (BRONJ), and chronic osteomyelitis using digital panoramic radiographs.

Materials and Methods

This study was performed in 25 patients who were prescribed PTX and tocopherol for treatment of ORN, BRONJ, and chronic osteomyelitis between January 2014 and May 2018 in Seoul National University Dental Hospital. Radiographic densities of the dental panorama were compared prior to starting PTX and tocopherol, at 3 months, and at 6 months after prescription. Radiographic densities were measured using Adobe Photoshop CS6 (Adobe System Inc., USA). Blood sample tests showing the degree of inflammation at the initial visit were considered the baseline and compared with results after 3 to 6 months. Statistical analysis was performed using the Mann-Whitney test and repeated measurement ANOVA using IBM SPSS 23.0 (IBM Corp., USA).

Results

Eight patients were diagnosed with ORN, nine patients with BRONJ, and the other 8 patients with chronic osteomyelitis. Ten of the 25 patients were men, average age was 66.32±14.39 years, and average duration of medication was 151.8±80.65 days (range, 56-315 days). Statistically significant increases were observed in the changes between 3 and 6 months after prescription (P<0.05). There was no significant difference between ORN, BRONJ, and chronic osteomyelitis. Only erythrocyte sedimentation rate (ESR) was statistically significantly lower than before treatment (P<0.05) among the white blood cell (WBC), ESR, and absolute neutrophil count (ANC).

Conclusion

Long-term use of PTX and tocopherol can be an auxiliary method in the treatment of ORN, BRONJ, or chronic osteomyelitis in jaw.

Efficacy of tocopherol and pentoxifylline combined therapy for women undergoing assisted reproductive treatment with poor endometrial development: a retrospective cohort study on 143 patients

Poor endometrial development during in vitro fertilization remains challenging. Indeed, no broadly accepted definition of poor endometrial development exists, and no treatment has shown any improvement in the condition. The aim of this study was to analyze whether treatment with a combination of pentoxifylline and tocopherol increases endometrial volume. This monocentric and retrospective study includes patients with previous miscarriages, in vitro fertilization failure, or poor endometrial development. The patients had an ultrasonography during the mid-luteal phase to assess both endometrial thickness and endometrial volume (EV). If the volume was less than 2 mL, they were given pentoxifylline (PTX) and tocopherol for at least 2 months before a second ultrasound assessment. One hundred and forty-four patients were analyzed. The mean duration of treatment was 132 days. The combination of tocopherol and PTX significantly increased the EV by 0.47 mL (p < 0.0001; 95% CI 0.38-0.57). The mean ± SD EV was 1.34 ± 0.38 mL and 1.82 ± 0.63 mL before and after the treatment respectively. No data concerning pregnancy rates were interpretable. We showed an improvement of poor endometrial proliferation with a treatment including PTX and tocopherol. These promising results should be followed up by a prospective study.

Biomechanical, histological, and radiological effects of different phosphodiesterase inhibitors on femoral fracture healing in rats

PURPOSE

To investigate the biomechanical, histological, and radiological effects of sildenafil and pentoxifylline on femoral fracture healing in rats.

METHODS

Forty-eight Sprague-Dawley rats were divided into three groups equally according to the pharmacological agents to be investigated. Femoral shaft fractures were formed in the left side. Group 1 (control group), group 2, and group 3 were administered with saline, sildenafil, and pentoxifylline during the fracture healing process, respectively. Eight rats from each group were euthanized on days 15 and 30. X-ray images of the rats were taken after euthanasia for radiographical examination. Femur samples were subjected to histopathological and biomechanical (three-point bending) examinations.

RESULTS

Radiologically, no difference between the Goldberg scores of the groups was found for day 15 ( p > 0.05), while higher Goldberg scores were obtained from group 2 than that of group 1 ( p > 0.05) and group 3 ( p < 0.05) for day 30. In the biomechanical analysis, higher mean breaking forces were found both for day 15 and day 30 from group 2 than those obtained from group 1 (for day 15 p > 0.05 and day 30 p > 0.05) and group 3 (for day 15 p < 0.05 and day 30 p < 0.01). Higher mean absorbed energy values were obtained from group 2 than those obtained from group 1 (for day 15 p > 0.05 and day 30 p < 0.05) and group 3 (for day 15 p < 0.01 and day 30 p < 0.01). A significant difference was not found between the histological scores of all groups ( p > 0.05) for day 15, while the histological score of group 1 on day 30 was found to be significantly lower than that of sildenafil and pentoxifylline groups ( p < 0.05).

CONCLUSION

Sildenafil had a positive effect on fracture healing, while pentoxifylline did not provide consistent positive effect.

New therapeutic insights into radiation-induced myocardial fibrosis

Radiation therapy (RT) for the treatment of thoracic tumors causes radiation-induced heart disease (RIHD). Radiation-induced myocardial fibrosis (RIMF) is both an acute and chronic stage of RIHD, depending on the specific pathology, and is thought to be a major risk factor for adverse myocardial remodeling and vascular changes. With the use of more three-dimensional conformal radiation regimens and early screenings and diagnoses for RIMF, the incidence of RIHD is declining, but it still must be carefully investigated to minimize the mortality and morbidity of patients with thoracic malignancies after RT treatment. Effective methods for preventing RIMF involve a decrease in the direct radiation dose in the heart, and early screening and diagnosis. Medications remain as a useful adjunct for preventing or treating RIMF. This review mainly discusses the cellular and molecular mechanisms underlying RIMF, and new therapeutic drugs that can potentially be developed from this knowledge.

Utilization of Vitamin E Analogs to Protect Normal Tissues While Enhancing Antitumor Effects

Despite advances in radiation delivery techniques, side effects of radiation therapy due to radiation exposure of normal tissues are common and can limit the deliverable dose to tumors. Significant interests lie in pharmacologic modifiers that may protect against normal tissue toxicity from cancer treatment while simultaneously enhancing the tumor response to therapy. While no such treatments are available in the clinic, this is an area of active preclinical and clinical research. This review summarizes research studies that provide evidence to indicate that tocotrienols, natural forms of vitamin E, are potent radiation protectors and may also have antitumor effects. Hence, several current clinical trials test tocotrienols as concomitant treatment in cancer therapies.

Pravastatin Reverses Established Radiation-Induced Cutaneous and Subcutaneous Fibrosis in Patients With Head and Neck Cancer: Results of the Biology-Driven Phase 2 Clinical Trial Pravacur

PURPOSE

The "PRAVACUR" phase 2 trial (NCT01268202) assessed the efficacy of pravastatin as an antifibrotic agent in patients with established cutaneous and subcutaneous radiation-induced fibrosis (RIF) after head and neck squamous cell carcinoma (HNSCC) radiation therapy and/or radiochemotherapy.

METHODS AND MATERIALS

The main inclusion criteria were: NSCC in remission, grade ≥2 cutaneous and subcutaneous neck RIF (National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.0), and no current treatment with statins or fibrates. Patients received pravastatin 40 mg/d for 12 months. The primary endpoint was reduction of RIF thickness by more than 30% at 12 months, as measured by cutaneous high-frequency ultrasonography. Secondary endpoints included RIF severity reduction, pravastatin tolerance, and quality of life.

RESULTS

Sixty patients with grade 2 (n = 37), grade 3 (n = 22), or grade 4 (n = 1) RIF were enrolled from February 2011 to April 2016. The mean interval between RIF diagnosis and pravastatin initiation was 17.1 months. Pravastatin was stopped before 11 months of treatment in 18 patients (because of grade ≥2 adverse events related to pravastatin in 8 patients [13%]). In the 40 patients in whom pravastatin efficacy was assessed by high-frequency ultrasonography at baseline and at 12 months of treatment, a reduction of RIF thickness ≥30% was observed in 15 of 42 patients (35.7%; 95% confidence interval, 21.6%-52.0%). At the 12-month clinical evaluation, RIF severity was decreased in 50% of patients (n = 21; 95% confidence interval, 34.2%-65.8%), and the patients' self-perception, mood state, and social functioning were significantly improved. Pravastatin was well tolerated, with a very low occurrence of grade 3 toxicities (myalgia, n = 1) and grade 2 toxicities (myalgia/arthralgia or esophagitis, n = 3).

CONCLUSIONS

This phase 2 prospective study supports the notion of radioinduced fibrosis reversibility. It showed that pravastatin (40 mg/d for 12 months) is an efficient antifibrotic agent in patients with grade ≥2 cutaneous and subcutaneous fibrosis after HNSCC radiation therapy.

Radiation Fibrosis Syndrome: the Evergreen Menace of Radiation Therapy

Fibrosis is a descriptive appellation referring to the obliteration of normal tissue components replaced by matrix and disorganized and varied collagen fibrils that result in the loss of organ function and frequent tissue contraction leading to death or significant deterioration in the quality of life. Radiation fibrosis syndrome (RFS) is a progressive fibrotic tissue sclerosis with various clinical symptoms in the irradiation field. It is usually a late complication of radiation therapy and may occur weeks or even years after treatment. It may affect the musculoskeletal, soft tissue, neural tissue, and cardiopulmonary systems. RFS is a serious and lifelong disorder that, nevertheless, may often be prevented when identified and rehabilitated early. Genetic factors likely play a significant role in the development of chronic fibrotic response to radiation injury that persists even after the initial insult is no longer present. Management of this syndrome is a complex process comprising medication, education, rehabilitation, and physical and occupational therapy. A bibliographical search was carried out in PubMed using the following keywords: "radiation fibrosis," "radiation fibrosis syndrome," and "radiation-induced fibrosis." We also reviewed the most relevant and recent series on the current management of RFS, and the reviewed data are discussed in this article. This review discusses the pathophysiology, evaluation, and treatment of neuromuscular, musculoskeletal, and functional disorders as late effects of radiation treatment.

Successful treatment of grade III osteoradionecrosis with mandibular fracture with pentoxifylline, tocopherol and clodronate

Osteoradionecrosis (ORN) is one of the most severe complications after head and neck radiotherapy. Once established, ORN is difficult to manage and is traditionally considered to be irreversible. Since the recent understanding of the pathophysiology of ORN is based on the concept of radiation-induced fibrosis, a new therapeutic medical regimen has been proposed comprising the combination of pentoxifylline, tocopherol and clodronate (PENTOCLO). A 55-year-old woman presented with grade III ORN with large intraoral bone exposure, a fracture of the left posterior horizontal branch and an orocutaneous fistula. Because she refused surgery, medical treatment with PENTOCLO was proposed. After 55months of treatment, there was complete mucosal coverage and complete consolidation of the fracture site around the orocutaneous fistula. PENTOCLO treatment can help some patients with grade III disease, as in this case. Further prospective randomized controlled trials are needed to confirm this result.

Osteoradionecrosis of the jaws: case series treated with adjuvant low-level laser therapy and antimicrobial photodynamic therapy

Background:

Osteoradionecrosis of the jaw (ORNJ) is the most severe and complex sequel of head and neck radiotherapy (RT) because of the bone involved, it may cause pain, paresthesia, foul odor, fistulae with suppuration, need for extra oral communication and pathological fracture. We treated twenty lesions of ORNJ using low-level laser therapy (LLLT) and antimicrobial photodynamic therapy (aPDT). The objective of this study was to stimulate the affected area to homeostasis and to promote the healing of the oral mucosa.

Methods:

We performed aPDT on the exposed bone, while LLLT was performed around the bone exposure (red spectrum) and on the affected jaw (infrared spectrum). Monitoring and clinical intervention occurred weekly or biweekly for 2 years.

Results:

100% of the sample presented clinical improvement, and 80% presented complete covering of the bone exposure by intact oral mucosa.

Conclusion:

LLLT and aPDT showed positive results as an adjuvant therapy to treat ORNJ.

Personalizing Breast Cancer Irradiation Using Biology: From Bench to the Accelerator

While adjuvant treatments of early breast cancers (BCs) had significantly improved patients’ overall survival, some of them will still develop locoregional relapses and/or severe late radio-induced toxicities. Here, we propose to review how to personalize locoregional treatment by identifying patients at high and low risk of locoregional relapse, patients at risk of late radio-induced side effects. We will, therefore, discuss how to enhance BC radiosensitivity. Finally, we will address how personalized radiotherapy could be implemented in prospective clinical trials.

The Role of the Mammalian Target of Rapamycin (mTOR) in Pulmonary Fibrosis

The phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR)-dependent pathway is one of the most integral pathways linked to cell metabolism, proliferation, differentiation, and survival. This pathway is dysregulated in a variety of diseases, including neoplasia, immune-mediated diseases, and fibroproliferative diseases such as pulmonary fibrosis. The mTOR kinase is frequently referred to as the master regulator of this pathway. Alterations in mTOR signaling are closely associated with dysregulation of autophagy, inflammation, and cell growth and survival, leading to the development of lung fibrosis. Inhibitors of mTOR have been widely studied in cancer therapy, as they may sensitize cancer cells to radiation therapy. Studies also suggest that mTOR inhibitors are promising modulators of fibroproliferative diseases such as idiopathic pulmonary fibrosis (IPF) and radiation-induced pulmonary fibrosis (RIPF). Therefore, mTOR represents an attractive and unique therapeutic target in pulmonary fibrosis. In this review, we discuss the pathological role of mTOR kinase in pulmonary fibrosis and examine how mTOR inhibitors may mitigate fibrotic progression.

Development and Characterization of an In Vitro Model for Radiation-Induced Fibrosis

Radiation-induced fibrosis (RIF) is a major side effect of radiotherapy in cancer patients with no effective therapeutic options. RIF involves excess deposition and aberrant remodeling of the extracellular matrix (ECM) leading to stiffness in tissues and organ failure. Development of preclinical models of RIF is crucial to elucidate the molecular mechanisms regulating fibrosis and to develop therapeutic approaches. In addition to radiation, the main molecular perpetrators of fibrotic reactions are cytokines, including transforming growth factor-β (TGF-β). We hypothesized that human oral fibroblasts would develop an in vitro fibrotic reaction in response to radiation and TGF-β. We demonstrate here that fibroblasts exposed to radiation followed by TGF-β exhibit a fibrotic phenotype with increased collagen deposition, cell proliferation, migration and invasion. In this in vitro model of RIF (RIF_iv), the early biological processes involved in fibrosis are demonstrated, along with increased levels of several molecules including collagen 1α1, collagen XIα1, integrin-α2 and cyclin D1 mRNA in irradiated cells. A clinically relevant antifibrotic agent, pentoxifylline, and a curcumin analogue both mitigated collagen deposition in irradiated fibroblast cultures. In summary, we have established an in vitro model for RIF that facilitates the elucidation of molecular mechanisms in radiation-induced fibrosis and the development of effective therapeutic approaches.

Protective effect of α-lipoic acid against radiation-induced fibrosis in mice

Radiation-induced fibrosis (RIF) is one of the most common late complications of radiation therapy. We found that α-lipoic acid (α-LA) effectively prevents RIF. In RIF a mouse model, leg contracture assay was used to test the in vivo efficacy of α-LA. α-LA suppressed the expression of pro-fibrotic genes after irradiation, both in vivo and in vitro, and inhibited the up-regulation of TGF-β1-mediated p300/CBP activity. Thus, α-LA prevents radiation-induced fibrosis (RIF) by inhibiting the transcriptional activity of NF-κB through inhibition of histone acetyltransferase activity. α-LA is a new therapeutic methods that can be used in the prevention-treatment of RIF.

Acute and Late Toxicities of Concurrent Chemoradiotherapy for Locally-Advanced Non-Small Cell Lung Cancer

For patients with unresectable locally-advanced non-small cell lung cancer (LA-NSCLC), concurrent chemoradiotherapy improves overall survival as compared to sequential chemotherapy and radiation therapy, but is associated with higher rates of toxicities. Acute, clinically significant esophagitis or pneumonitis can occur in one in five patients. The risks of esophagitis and pneumonitis can impact the decision to deliver concurrent therapy and limit the total dose of radiation therapy that is delivered. Hematologic toxicities and emesis are common toxicities from systemic therapies for LA-NSCLC and can result in delaying chemotherapy dosing or chemotherapy dose reductions. Late treatment morbidities, including pulmonary fibrosis and cardiac toxicities, can also significantly impact quality of life and potentially even survival. Recent advances in radiation therapy treatment delivery, better knowledge of normal tissue radiotherapy tolerances and more widespread and improved uses of supportive care and medical management of systemic therapy toxicities have improved the therapeutic ratio and reduced the rates of chemoradiotherapy-induced toxicities. This review details the acute and late toxicities associated with definitive chemoradiotherapy for LA-NSCLC and discusses toxicity management and strategies to mitigate the risks of treatment-related toxicities.

Radiation-Induced Fibrosis: Mechanisms and Opportunities to Mitigate. Report of an NCI Workshop, September 19, 2016

A workshop entitled "Radiation-Induced Fibrosis: Mechanisms and Opportunities to Mitigate" (held in Rockville, MD, September 19, 2016) was organized by the Radiation Research Program and Radiation Oncology Branch of the Center for Cancer Research (CCR) of the National Cancer Institute (NCI), to identify critical research areas and directions that will advance the understanding of radiation-induced fibrosis (RIF) and accelerate the development of strategies to mitigate or treat it. Experts in radiation biology, radiation oncology and related fields met to identify and prioritize the key areas for future research and clinical translation. The consensus was that several known and newly identified targets can prevent or mitigate RIF in pre-clinical models. Further, basic and translational research and focused clinical trials are needed to identify optimal agents and strategies for therapeutic use. It was felt that optimally designed preclinical models are needed to better study biomarkers that predict for development of RIF, as well as to understand when effective therapies need to be initiated in relationship to manifestation of injury. Integrating appropriate endpoints and defining efficacy in clinical trials testing treatment of RIF were felt to be critical to demonstrating efficacy. The objective of this meeting report is to (a) highlight the significance of RIF in a global context, (b) summarize recent advances in our understanding of mechanisms of RIF,

Repurposing Pentoxifylline for the Treatment of Fibrosis: An Overview

Fibrosis is a potentially debilitating disease with high morbidity rates. It is estimated that half of all deaths that occur in the USA are attributed to fibrotic disorders. Fibrotic disorders are characterized primarily by disruption in the extracellular matrix deposition and breakdown equilibrium, leading to the accumulation of excessive amounts of extracellular matrix. Given the potentially high prevalence of fibrosis and the paucity of agents currently available for the treatment of this disease, there is an urgent need for the identification of drugs that can be utilized to treat the disease. Pentoxifylline is a methylxanthine derivative that is currently approved for the treatment of vascular diseases, in particular, claudication. Pentoxifylline has three main properties: improving the rheological properties of blood, anti-inflammatory, and antioxidative. Recently, the effectiveness of pentoxifylline in the treatment of fibrosis via attenuating and reversing fibrotic lesions has been demonstrated in several clinical trials and animal studies. As a result of the limited availability of antifibrotic agents in the long-term treatment of fibrosis that can attenuate and even reverse fibrotic lesions effectively, it would be of particular importance to consider the potential clinical utility of pentoxifylline in the treatment of fibrosis. Thus, this paper discusses the evolving roles of pentoxifylline in the treatment of different types of fibrosis.

IPW-5371 Proves Effective as a Radiation Countermeasure by Mitigating Radiation-Induced Late Effects

There is an ongoing and significant need for radiation countermeasures to reduce morbidities and mortalities associated with exposure of the heart and lungs from a radiological or nuclear incidents. Radiation-induced late effects occur months to years after exposure, stemming from significant tissue damage and remodeling, resulting in fibrosis and loss of function. TGF-β is reported to play a role in both pulmonary and cardiac fibrosis. We investigated the ability of a small molecule TGF-β receptor 1 inhibitor, IPW-5371, to mitigate the effects of thoracic irradiation in C57L/J mice, a murine model that most closely resembles that observed in humans in the induction of fibrosis and dose response. To simulate a radiological event, radiation was administered in two doses: 5 Gy total-body irradiation (eliciting a whole-body response) and immediately after that, a thoracic "top-up" of 6.5 Gy irradiation, for a total dose of 11.5 Gy to the thorax. IPW-5371 was administered once daily, orally, starting 24 h postirradiation for 6 or 20 weeks at a dose of 10 mg/kg or 30 mg/kg. Animals were monitored for a period of 180 days for survival, and cardiopulmonary injury was assessed by echocardiography, breathing rate and arterial oxygen saturation. Exposure of the thorax (11.5 Gy) induced both pulmonary and cardiac injury, resulting in a reduced life span with median survival of 135 days. IPW-5371 treatment for 6 weeks, at both 10 mg/kg and 30 mg/kg, delayed disease onset and mortality, with median survival of 165 days. Twenty weeks of IPW-5371 treatment at 30 mg/kg preserved arterial O₂ saturation and cardiac contractile reserve and resulted in significant decreases in breathing frequency and cardiac and pulmonary fibrosis. This led to dramatic improvement in survival compared to the irradiated, vehicle-treated group (P < 0.001), and was statistically insignificant from the nonirradiated group. We observed that IPW-5371 treatment resulted in decreased pSmad3 tissue levels, confirming the effect of IPW-5371 on TGF-β signaling. These results demonstrate that IPW-5371 represents a potentially promising radiation countermeasure for the treatment of radiation-induced late effects.

Bisphosphonate-related osteonecrosis of jaws in advanced stage breast cancer was detected from bone scan: a case report

Bisphosphonates (BPs) are indicated to treat skeletal-related events (SREs) for cancer patients with bone metastasis. We report a 79-year-old woman with advanced stage breast cancer with bone metastasis who was prescribed BPs (zoledronate), then developed osteonecrosis of jaw. We provide a brief review of the pathogenesis, diagnosis and treatment of this complication.

Radiation Fibrosis Syndrome Imitating Breast Cancer Recurrence; A Case Report

Nowadays, surgery, radiotherapy and chemotherapy are the most frequently used modalities in the treatment of breast cancer. It is very well-known that some severe complications may result from after these treatments. Early and late complications of radiotherapy are well known. The complications of radiation therapy may be seen in (early) or after three months (late-delayed) of periods. These complications may be related with direct or indirect effect of radiation. The radiation fibrosis syndrome is a progressive fibrotic tissue sclerosis together with various clinical symptoms in the irradiation field. It is usually a late finding of radiation therapy and may be seen weeks or even years after the treatment. Many systems such as musculo-skeletal, soft tissue, neural tissue and cardiopulmonary system may be affected. In this report, we present a case of a breast cancer treated with breast conserving surgery and radiation therapy twelve years ago. The patient had ipsilateral lymphedema, right axillary mass, and pain during arm and shoulder mobilization. Her physical examination and radiologic findings revealed a big mass invading right thoracic wall, thoracic cavity and the axilla. Histopathological evaluation performed after tru-cut and open biopsy from the mass showed fibrosis resulting from radiation therapy.

Use of pentoxifylline and tocopherol in radiation-induced fibrosis and fibroatrophy

Radiation-induced fibrosis in the head and neck is a well-established pathophysiological process after radiotherapy. Recently pentoxifylline and tocopherol have been proposed as treatments to combat the late complications of radiation-induced fibrosis and a way of dealing with osteoradionecrosis. They both have a long history in the management of radiation-induced fibrosis at other anatomical sites. In this paper we review their use in sites other than the head and neck to illustrate the potential benefit that they offer to our patients.

IL-13 is a therapeutic target in radiation lung injury

Pulmonary fibrosis is a potentially lethal late adverse event of thoracic irradiation. Prior research indicates that unrestrained TGF-β1 and/or type 2 cytokine-driven immune responses promote fibrosis following radiation injury, but the full spectrum of factors governing this pathology remains unclear. Interleukin 13 (IL-13) is a key factor in fibrotic disease associated with helminth infection, but it is unclear whether it plays a similar role in radiation-induced lung fibrosis. Using a mouse model, we tested the hypothesis that IL-13 drives the progression of radiation-induced pulmonary fibrosis. Irradiated lungs from wild-type c57BL/6NcR mice accumulated alternatively-activated macrophages, displayed elevated levels of IL-13, and extensive fibrosis, whereas IL-13 deficient mice were resistant to these changes. Furthermore, plasma from irradiated wild-type mice showed a transient increase in the IL-13 saturated fraction of the circulating decoy receptor IL-13Rα2. Finally, we determined that therapeutic neutralization of IL-13, during the period of IL-13Rα2 saturation was sufficient to protect mice from lung fibrosis. Taken together, our results demonstrate that IL-13 is a major regulator of radiation-induced lung injury and demonstrates that strategies focusing on IL-13 may be useful in screening for timely delivery of anti-IL-13 therapeutics.

Chronic radiation-induced dermatitis: challenges and solutions

Chronic radiation dermatitis is a late side effect of skin irradiation, which may deteriorate patients’ quality of life. There is a lack of precise data about its incidence; however, several risk factors may predispose to the development of this condition. It includes radiotherapy dose, fractionation, technique, concurrent systemic therapy, comorbidities, and personal and genetic factors. Chronic radiation dermatitis is mostly caused by the imbalance of proinflammatory and profibrotic cytokines. Clinical manifestation includes changes in skin appearance, wounds, ulcerations, necrosis, fibrosis, and secondary cancers. The most severe complication of irradiation is extensive radiation-induced fibrosis (RIF). RIF can manifest in many ways, such as skin induration and retraction, lymphedema or restriction of joint motion. Diagnosis of chronic radiation dermatitis is usually made by clinical examination. In case of unclear clinical manifestation, a biopsy and histopathological examination are recommended to exclude secondary malignancy. The most effective prophylaxis of chronic radiation dermatitis is the use of proper radiation therapy techniques to avoid unnecessary irradiation of healthy skin. Treatment of chronic radiation dermatitis is demanding. The majority of the interventions are based only on clinical practice. Telangiectasia may be treated with pulse dye laser therapy. Chronic postirradiation wounds need special dressings. In case of necrosis or severe ulceration, surgical intervention may be considered. Management of RIF should be complex. Available methods are rehabilitative care, pharmacotherapy, hyperbaric oxygen therapy, and laser therapy. Future challenges include the assessment of late skin toxicity in modern irradiation techniques. Special attention should be paid on genomics and radiomics that allow scientists and clinicians to select patients who are at risk of the development of chronic radiation dermatitis. Novel treatment methods and clinical trials are strongly needed to provide more efficacious therapies.

Human epidermal stem cells: Role in adverse skin reactions and carcinogenesis from radiation

In human skin, keratinopoiesis is based on a functional hierarchy among keratinocytes, with rare slow-cycling stem cells responsible for the long-term maintenance of the tissue through their self-renewal potential, and more differentiated daughter progenitor cells actively cycling to permit epidermal renewal and turn-over every month. Skin is a radio-responsive tissue, developing all types of radiation damage and pathologies, including early tissue reactions such as dysplasia and denudation in epidermis, and later fibrosis in the dermis and acanthosis in epidermis, with the TGF-beta 1 pathway as a known master switch. Also there is a risk of basal cell carcinoma, which arises from epidermal keratinocytes, notably after oncogenic events in PTCH1 or TP53 genes. This review will cover the mechanisms of adverse human skin reactions and carcinogenesis after various types of exposures to ionizing radiation, with comparison with animal data when necessary, and will discuss the possible role of stem cells and their progeny in the development of these disorders. The main endpoints presented are basal cell intrinsic radiosensitivity, genomic stability, individual factors of risk, dose specific responses, major molecular pathways involved and the cellular origin of skin reactions and cancer. Although major advances have been obtained in recent years, the precise implications of epidermal stem cells and their progeny in these processes are not yet fully characterized.