Natural History of Oral HPV Infection among Indigenous South Australians.

This study aims to describe the natural history of and identify the risk factors associated with oral human papillomavirus (HPV) infections in an Australian Indigenous cohort. A longitudinal cohort study design, with baseline (2018), 12-month, and 24-month data obtained from Indigenous Australians aged 18+ years in South Australia, was performed. Face-to-face interviews were conducted, and saliva samples for HPV testing were collected at each time point. Basic descriptive analyses were conducted to calculate prevalence, incidence, persistence, clearance, and incidence proportions of any HPV infection. Multivariable logistic regression analyses with adjusted prevalence ratios (PRs) were conducted to identify risk factors associated with oral HPV infection. Among 993 participants with valid saliva samples, 44 HPV types were identified. The prevalence of infection with any oral HPV infection was 51.3%, high-risk HPV was 11%, and types implicated in Heck's disease (HPV 13 or 32) was 37.4%. The incidence, persistence, and clearance of any and high-risk HPV infections were 30.7%, 11.8% and 33.3% vs. 9.3%, 2.8%, and 9%, respectively. Our findings indicate that the prevalence, incidence, and persistence of oral HPV infection in a large sample of Indigenous Australians were high, and clearance was low. Oral sex behaviours and recreational drug use were risk factors associated with incident high-risk HPV infection.

Advanced statistics identification of participant and treatment predictors associated with severe adverse effects induced by fluoropyrimidine-based chemotherapy.

PURPOSE: Adverse effects following fluoropyrimidine-based chemotherapy regimens are common. However, there are no current accepted diagnostic markers for prediction prior to treatment, and the underlying mechanisms remain unclear. This study aimed to determine genetic and non-genetic predictors of adverse effects. METHODS: Genomic DNA was analyzed for 25 single nucleotide polymorphisms (SNPs). Demographics, comorbidities, cancer and fluoropyrimidine-based chemotherapy regimen types, and adverse effect data were obtained from clinical records for 155 Australian White participants. Associations were determined by bivariate analysis, logistic regression modeling and Bayesian network analysis. RESULTS: Twelve different adverse effects were observed in the participants, the most common severe adverse effect was diarrhea (12.9%). Bivariate analysis revealed associations between all adverse effects except neutropenia, between genetic and non-genetic predictors, and between 8 genetic and 12 non-genetic predictors with more than 1 adverse effect. Logistic regression modeling of adverse effects revealed a greater/sole role for six genetic predictors in overall gastrointestinal toxicity, nausea and/or vomiting, constipation, and neutropenia, and for nine non-genetic predictors in diarrhea, mucositis, neuropathy, generalized pain, hand-foot syndrome, skin toxicity, cardiotoxicity and fatigue. The Bayesian network analysis revealed less directly associated predictors (one genetic and six non-genetic) with adverse effects and confirmed associations between six adverse effects, eight genetic predictors and nine non-genetic predictors. CONCLUSION: This study is the first to link both genetic and non-genetic predictors with adverse effects following fluoropyrimidine-based chemotherapy. Collectively, we report a wealth of information that warrants further investigation to elucidate the clinical significance, especially associations with genetic predictors and adverse effects.

Factors Associated With Oral Mucositis Severity in Children Who Have Received Chemotherapy.

Oral mucositis (OM) is a major complication for pediatric oncology patients undergoing cancer therapy. This paper aimed to report on the relationship between OM severity and various patient factors as well as to compare 2 scales used to assess OM severity. The severity of 68 separate episodes of OM in 47 pediatric oncology patients who had received chemotherapy was regularly assessed using the Children's International Mucositis Evaluation Scale (ChIMES) and World Health Organization (WHO) scale. The mean time from the start of the patients' chemotherapy block to the onset of OM was 8.4 days (±4.0), the median duration of OM was 7.0 days (4.0, 10.5) and median admission duration was 7.0 days (4.5, 13.5). There was a significant relationship between the severity of OM and the duration of symptoms ( P <0.001), patient's admission length ( P <0.001) and low neutrophil count. With decreasing neutrophil count, the severity of OM and number of pain medications used increased. Neutrophil count recovery coincided with resolution of OM. No significant relationship was found between OM severity and the child's cancer diagnosis. The 2 scales used to measure OM severity showed substantial agreement.

Diagnostic Accuracy of Confocal Laser Endomicroscopy for the Diagnosis of Oral Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis.

BACKGROUND: Advances in treatment approaches for patients with oral squamous cell carcinoma (OSCC) have been unsuccessful in preventing frequent recurrences and distant metastases, leading to a poor prognosis. Early detection and prevention enable an improved 5-year survival and better prognosis. Confocal Laser Endomicroscopy (CLE) is a non-invasive imaging instrument that could enable an earlier diagnosis and possibly help in reducing unnecessary invasive surgical procedures. OBJECTIVE: To present an up to date systematic review and meta-analysis assessing the diagnostic accuracy of CLE in diagnosing OSCC. MATERIALS AND METHODS: PubMed, Scopus, and Web of Science databases were explored up to 30 June 2021, to collect articles concerning the diagnosis of OSCC through CLE. Screening: data extraction and appraisal was done by two reviewers. The quality of the methodology followed by the studies included in this review was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. A random effects model was used for the meta-analysis. RESULTS: Six studies were included, leading to a total number of 361 lesions in 213 patients. The pooled sensitivity and specificity were 95% (95% CI, 92-97%; I2 = 77.5%) and 93% (95% CI, 90-95%; I2 = 68.6%); the pooled positive likelihood ratios and negative likelihood ratios were 10.85 (95% CI, 5.4-21.7; I2 = 55.9%) and 0.08 (95% CI, 0.03-0.2; I2 = 83.5%); and the pooled diagnostic odds ratio was 174.45 (95% CI, 34.51-881.69; I2 = 73.6%). Although risk of bias and heterogeneity is observed, this study validates that CLE may have a noteworthy clinical influence on the diagnosis of OSCC, through its high sensitivity and specificity. CONCLUSIONS: This review indicates an exceptionally high sensitivity and specificity of CLE for diagnosing OSCC. Whilst it is a promising diagnostic instrument, the limited number of existing studies and potential risk of bias of included studies does not allow us to draw firm conclusions. A conclusive inference can be drawn when more studies, possibly with homogeneous methodological approach, are performed.

Cohort profile: indigenous human papillomavirus and oropharyngeal squamous cell carcinoma study - a prospective longitudinal cohort.

PURPOSE: Our aims are to: (1) estimate prevalence, incidence, clearance and persistence of oral human papillomavirus (HPV) infection among Indigenous Australians; (2) identify risk factors associated with oropharyngeal squamous cell carcinoma (OPSCC)-related HPV types (HPV 16 or 18); (3) develop HPV-related health state valuations and; (4) determine the impact on OPSCC and cervical cancers, and the cost-effectiveness of extending publicly-funded HPV vaccination among Indigenous Australians. PARTICIPANTS: Participants were recruited from February 2018 to January 2019. Twelve-month follow-up occurred from March 2019 to March 2020. Participants provided socio-demographic characteristics, health-related behaviours including tobacco and alcohol use and sexual history. Health state preferences in regard to HPV vaccination, knowledge regarding HPV infection, OPSCC and cervical cancer were collected using a two-stage standard gamble approach. Participants provided saliva samples and DNA for microbial genotyping was extracted. FINDINGS TO DATE: Of the 910 participants who were positive for ß-globin at baseline, 35% had any oral HPV infection. The most prevalent HPV types were 13 or 32 (Heck's disease; 23%). The second most prevalent types were associated with OPSCC (HPV 16 or 18; 3.3%). Of the 645 participants who were positive for ß-globin at 12-month follow-up, 43% had any HPV infection. Of these, 33% were HPV types 13 or 32 and 2.5% were HPV 16 or 18. Some 588 participants had ß-globin positive oral samples at baseline and 12-month follow-up. The prevalence of any oral HPV infection increased from 34% at baseline to 44% at 12-month follow-up; due to increases in HPV types 13 or 32 (20% at baseline and 34% at 12-month follow-up). FUTURE PLANS: Further funding will be sought to continue follow-up of this cohort, and to include (after a full medical history) a thorough clinical examination of the external head and neck; a complete oral examination and examination of the oropharynx. Blood tests for early stage OPSCC will also be undertaken.

High-Risk Human Papillomavirus-Related Oropharyngeal Squamous Cell Carcinoma Among Non-Indigenous and Indigenous Populations: A Systematic Review.

OBJECTIVE: To estimate the prevalence of oral high-risk human papillomavirus (hr-HPV) infection and the proportion of hr-HPV-related oropharyngeal squamous cell carcinoma (OPSCC) among Indigenous and non-Indigenous populations. DATA SOURCE: Electronic database searches of PubMed, PubMed Central, Embase, MEDLINE, Scope, and Google Scholar were conducted for articles published from January 2000 until November 2019. REVIEW METHODS: Studies were included with a minimum of 100 cases assessing hr-HPV infection in either population samples or oropharyngeal cancer tumor series. The objective was to conduct meta-analyses to calculate the pooled prevalence of oral hr-HPV infection by adjusting for age group or sex in primary studies, the incidence of OPSCC, and the proportion of hr-HPV-related OPSCC in Indigenous people and non-Indigenous/general populations. RESULTS: We identified 47 eligible studies from 157 articles for meta-analyses. The pooled prevalence of oral hr-HPV infection was 7.494% (95% CI, 5.699%-9.289%) in a general population, with a higher prevalence among men (10.651%) than women (5.176%). The pooled incidence rate was 13.395 (95% CI, 9.315-17.475) and 7.206 (95% CI, 4.961-9.450) per 100,000 person-years in Indigenous and non-Indigenous populations, respectively. The overall pooled proportion of hr-HPV-related OPSCC was 50.812% (95 CI, 41.656%-59.969%). The highest proportion was in North America (60.221%), while the lowest proportion was in the Asia-Pacific (34.246%). CONCLUSION: Our findings suggest that in the general population, the prevalence of oral hr-HPV infection is lower among females and those in younger age groups. The incidence of OPSCC was higher among Indigenous than non-Indigenous populations, with the proportion being highest in North America.

MASCC/ISOO clinical practice guidelines for the management of mucositis secondary to cancer therapy.

BACKGROUND: Mucositis is a significant toxicity of cancer therapy with numerous systemic sequelae. The goal of this systematic review was to update the Multinational Association of Supportive Care in Cancer and International Society of Oral Oncology (MASCC/ISOO) Clinical Practice Guidelines for the management of mucositis. METHODS: The literature was reviewed systematically to identify interventions for mucositis. Studies were rated according to the presence of major and minor flaws according to previously published criteria. The body of evidence for each intervention and in each treatment setting was assigned a level of evidence based on previously published criteria. Guidelines were developed based on the level of evidence, with 3 possible guideline determinations: recommendation, suggestion, or no guideline possible. RESULTS: The guideline covers evidence from 1197 publications related to oral or gastrointestinal mucositis. Thirteen new guidelines were developed for or against the use of various interventions in specific treatment settings, and 11 previous guidelines were confirmed after aa review of new evidence. Thirteen previously established guidelines were carried over because there was no new evidence for these interventions. CONCLUSIONS: The updated MASCC/ISOO Clinical Practice Guidelines for mucositis provide professional health caregivers with a clinical setting-specific, evidence-based tool to help with the management of mucositis in patients who have cancer.

Prevalence of Oral Human Papillomavirus Infection Among Australian Indigenous Adults.

Importance: Human papillomavirus (HPV) infection is associated with oropharyngeal squamous cell carcinoma. International estimates suggest overall oral HPV prevalence is 7.5%, with prevalence of oral HPV types 16 and 18 being 1.6%; prior Australian estimates suggest oral HPV prevalence is 2.3%, with HPV-16 and HPV-18 being 1.3%. Objectives: To estimate the prevalence of oral HPV infection among Indigenous Australians and to report the prevalence of factors associated with high-risk HPV types (ie, HPV-16 and HPV-18) and HPV types linked with Heck disease (ie, HPV-13 and HPV-32). Design, Setting, and Participants: This cross-sectional study analyzed HPV screening results from saliva samples collected from 1011 Indigenous Australians between February 2018 and January 2019. Data were analyzed from May 2018 to May 2019. Recruitment occurred through Aboriginal Community Controlled Health Organisations in South Australia. Eligibility included identifying as Indigenous, residing in South Australia, and being aged 18 years or older. Main Outcomes and Measures: Saliva samples were collected, with microbial DNA for genotyping extracted. Sociodemographic parameters, health-related behaviors, and sexual history data were collected. Analyses were stratified by sex as well as by HPV types 13 and 32 (Heck disease) and 16 and 18 (high risk of oropharyngeal squamous cell carcinoma). Multivariable analyses were conducted to obtain adjusted odds ratios (ORs). Results: Data were obtained for 910 participants (median [interquartile range] age, 37 [27-51] years); 595 participants (65%) were female and 572 (63%) resided in nonmetropolitan locations. In all, 321 saliva samples (35.3%; 95% CI, 32.2%-38.4%) were positive for oral HPV (106 [33.7%] men; 215 [36.1%] women). The highest prevalence was found for HPV types 13 and 32 (207 [22.7%] total; 60 [19.0%] men; 147 [24.7%] women) followed by HPV types 16 and 18 (30 [3.3%] total; 9 [2.9%] men; 21 [3.5%] women). After multivariable analysis, risk factors associated with HPV types 13 and 32 included nonmetropolitan residential status (OR, 2.06; 95% CI, 1.10-3.88) and not having had a tonsillectomy (OR, 2.74; 95% CI, 1.05-7.16). Among women, having obtained a high school education or less was associated with lower odds of HPV-16 and HPV-18 infection (OR, 0.16; 95% CI, 0.03-0.97). Conclusions and Relevance: Prevalence of oral HPV infection in a large sample of Indigenous Australians was high, with one-third testing positive. The most prevalent HPV types were those associated with Heck disease. The prevalence of HPV types associated with oropharyngeal squamous cell carcinoma exceeded both Australian and international population-level estimates.

Systematic review of growth factors and cytokines for the management of oral mucositis in cancer patients and clinical practice guidelines.

PURPOSE: To update the clinical practice guidelines for the use of growth factors and cytokines for the prevention and/or treatment of oral mucositis (OM). METHODS: A systematic review was conducted by the Mucositis Study Group of the Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO). The body of evidence for each intervention, in each cancer treatment setting, was assigned an evidence level. The findings were added to the database used to develop the 2014 MASCC/ISOO clinical practice guidelines. Based on the evidence level, the following guidelines were determined: recommendation, suggestion, and no guideline possible. RESULTS: A total of 15 new papers were identified within the scope of this section and were merged with 51 papers that were reviewed in the previous guidelines update. Of these, 14, 5, 13, 2, and 1 were randomized controlled trials about KGF-1, G-CSF, GM-CSF, EGF, and erythropoietin, respectively. For the remaining agents there were no new RCTs. The previous recommendation for intravenous KGF-1 in patients undergoing autologous hematopoietic stem cell transplantation (HSCT) conditioned with high-dose chemotherapy and TBI-based regimens is confirmed. The previous suggestion against the use of topical GM-CSF for the prevention of OM in the setting of high-dose chemotherapy followed by autologous or allogeneic stem cell transplantation remains unchanged. CONCLUSIONS: Of the growth factors and cytokines studied for the management of OM, the evidence supports a recommendation in favor of KGF-1 and a suggestion against GM-CSF in certain clinical settings.

Retrospective analysis of South Australian pediatric oral and maxillofacial pathology over a 16-year period.

AIM: The epidemiological features and distribution of pediatric oral and maxillofacial pathology in South Australia, Australia, is unknown. The medical and dental specialties involved in the management of oral and maxillofacial pathology is also unknown. The aim of the present study was to audit oral and maxillofacial pathology specimens submitted for diagnosis in a pediatric tertiary-referral hospital setting. METHODS: Histopathology records were retrieved from the Women's and Children's Hospital, Adelaide over a 16-year period. Age, sex, histopathological diagnosis, location of the lesion, and department involved were recorded. Lesions were classified into 12 categories. RESULTS: A total of 676 lesions involving the oral and maxillofacial region were collected from patients aged 0-18 years. The mean age was 8.71 years. Diagnosis was not significantly associated with sex (P = 0.123). A total of 97.37% of cases were benign, with connective tissue and salivary gland lesions most frequently biopsied and more frequently biopsied by medical departments. Mucoceles (19.23%) were most commonly diagnosed, followed by dentigerous cysts (5.62%). The Department of Paediatric Dentistry submitted most specimens, followed by the Department of Otolaryngology, the Australian Craniofacial Unit, and the Departments of Paediatric Surgery and Plastics. CONCLUSION: The present study provides valuable understanding into the epidemiological features of, and the specialties involved in, oral and maxillofacial histopathology in an Australian pediatric population.

Histological analysis of 41 dentigerous cysts in a paediatric population.

BACKGROUND: Dentigerous cysts are usually of developmental nature but may be of inflammatory origin especially in paediatric populations. It is important to understand the histological features of dentigerous cysts to enable accurate diagnosis. The aim of this study is to present epidemiological, clinical features and histopathological features of dentigerous cysts seen in a paediatric tertiary referral hospital. METHOD: The medical, radiographic and histopathology records of the Department of Pathology, Women's and Children's Hospital, Adelaide, Australia, during January 1998 to December 2013 were reviewed for patients with dentigerous cysts. All cases were re-examined by a specialist oral pathologist, consultant paediatric pathologist and paediatric dentistry registrar. RESULTS: Forty-one cases of dentigerous cysts were found. Patients in the permanent dentition were most frequently affected. Male predilection was observed (male:female 2.42:1). The posterior mandible was the most frequently affected region (63.42%) although maxillary canines were the teeth most commonly associated with dentigerous cysts (29.27%). The majority of cases were incidental findings. Squamous epithelium showing pseudoepitheliomatous hyperplasia (46%) was frequently observed and was significantly present with thicker epithelium (P < 0.0001) and an acute and chronic inflammatory infiltrate (P < 0.001). Inflammatory infiltrate was seen in 75.6% of cases. CONCLUSIONS: The current study provides increased knowledge of the histological features of dentigerous cysts in a large retrospective series of paediatric patients and provides further evidence regarding the frequency of inflammatory dentigerous cysts.

Vascular endothelial growth factor (VEGF), transforming growth factor beta (TGFß), angiostatin, and endostatin are increased in radiotherapy-induced gastrointestinal toxicity.

PURPOSE: Radiotherapy-induced gut toxicity (RIGT) is a debilitating effect of radiotherapy for cancer, often resulting in significant diarrhea and pain. Previous studies have highlighted roles of the intestinal microvasculature and matrix metalloproteinases (MMPs) in the development of RIGT. We hypothesized vascular mediators would be significantly altered in a dark agouti (DA) rat model of RIGT. Additionally, we aimed to assess the effect of MMP-2 and -9 inhibition on the response of tumor-associated microvascular endothelial cells (TAMECs) to radiation. METHODS: DA rats were administered 2.5 Gy abdominal irradiation (3 times/week over 6 weeks). Vascular endothelial growth factor (VEGF), transforming growth factor beta (TGFß), von Willebrand factor (VWF), angiostatin, and endostatin expression was assessed at 3, 6, and 15 weeks. Additionally, DA rat mammary adenocarcinoma tumor-associated microvascular endothelial cells (TAMECs) were used to assess the effects of radiation (12 Gy) and the MMP inhibitor SB-3CT on MMP, VEGF, and TGFß expression, and cell viability. RESULTS: VEGF mRNA expression was significantly increased in the colon at week 15 (p = .0012), and TGFß mRNA expression was significantly increased in both the jejunum and colon at week 3 (p = .0280 and p = .0310, respectively). Endostatin immunostaining was significantly increased at week 3 (p = .0046), and angiostatin at 3 and 6 weeks (p = .0022 and p = .0135, respectively). MMP-2 and -9 mRNA and total protein levels were significantly increased following irradiation of TAMECs. Although this increase was significantly attenuated by SB-3CT, it did not significantly alter endothelial cell viability or VEGF and TGFß mRNA expression. CONCLUSIONS: Findings of this study support the involvement of VEGF, TGFß, angiostatin, endostatin, and MMP-2 in the pathobiology of RIGT. However, the relationship between these mediators is complex and needs further investigation to improve understanding of their therapeutic potential in RIGT.

Matrix metalloproteinase expression is altered in the small and large intestine following fractionated radiation in vivo.

PURPOSE: Radiotherapy-induced gut toxicity (RIGT) is associated with significant diarrhoea, pain and rectal bleeding. Matrix metalloproteinases (MMPs) have been reported to be involved in chemotherapy-induced gut toxicity and RIGT following single-dose irradiation in vivo. We therefore proposed MMPs would be involved in the pathobiology of RIGT following fractionated irradiation. METHODS: Dark Agouti rats were treated with fractionated radiation (3 × 2.5 Gy/week for 6 weeks). Rats were killed at 3, 6 and 15 weeks to represent acute and chronic toxicities. Sections of jejunum and colon were immunostained for MMP-1, MMP-2, MMP-9 and MMP-14. Relative mRNA expression in jejunum and colon was quantified by RT-PCR for MMP-1, MMP-2, MMP-9 and MMP-14. Western blotting was also conducted on jejunum and colon tissue collected at week 6 to determine protein levels of pro- and active MMP-2. RESULTS: MMP-2 total protein levels, determined by western blotting, significantly increased in both the jejunum (p = 0.0359) and the colon (p = 0.0134) 6 weeks into the fractionated radiation schedule. MMP-1, MMP-2, and MMP-14 mRNA expression significantly increased in the jejunum. MMP-2 mRNA expression was also significantly increased in the colon. Immunostaining of MMP-2 was observed to be increased in both crypt enterocytes and the lamina propria. CONCLUSIONS: MMP-2 plays a role in the pathobiology of gastrointestinal toxicities following fractionated irradiation. Whilst MMP-1 and MMP-14 mRNA expression was increased, this occurred only in the jejunum, suggesting MMPs are differentially involved in RIGT depending on the intestinal region. Further studies are needed to elucidate the role these mediators play in the development and potentiation of RIGT.

Fractionated abdominal irradiation induces intestinal microvascular changes in an in vivo model of radiotherapy-induced gut toxicity.

PURPOSE: Radiotherapy-induced gut toxicity (RIGT) is associated with diarrhoea, pain and rectal bleeding and can occur as an acute or chronic toxicity. The microvasculature has been shown to be altered in the development of RIGT; however, the features are not yet characterized. We hypothesized that apoptosis of microvascular cells would occur early in the gastrointestinal tract following fractionated irradiation, followed by late microvascular changes, including sclerosis and telangiectasis. METHODS: Female Dark Agouti rats were treated with a 6-week fractionated radiation schedule of 3 × 2.5 Gy doses per week localized to the abdomen. At 3, 6 and 15 weeks, the intestines were assessed for markers of acute and chronic injury including morphological changes, collagen deposition, apoptosis and proliferation. RESULTS: Apoptosis of microvascular cells significantly increased at 6 and 15 weeks in the jejunum (p = 0.0026 and p = 0.0062, respectively) and at 6 and 15 weeks in the colon (p < 0.0001 and p = 0.0005, respectively) in rats receiving fractionated radiation to the abdomen. Histopathological changes of the colon microvasculature were also seen from week 3, including thickening of the lamina propria and dilated, thickened, telangiectatic vessels. CONCLUSIONS: Findings of this study provide evidence of regional and timing-specific changes in the intestinal microvasculature in response to fractionated radiotherapy which may play a role in development of both acute and chronic RIGT.

A systematic review of oral herpetic viral infections in cancer patients: commonly used outcome measures and interventions.

PURPOSE: To review the literature for outcome measures for oral viral infections in cancer patients. A secondary aim was to update the Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO) clinical practice guidelines for the management of oral viral infections in cancer patients. METHODS: Databases were searched for articles published in the English language, 1981-2013. Studies that met the eligibility criteria were reviewed systematically. The data about the outcome measures were classified according to the aim of the study: prevention, treatment, or non-interventional. The results of interventional studies were compared to the 2010 MASCC/ISOO publication. RESULTS: Multiple clinical and laboratory tests were used to measure oral viral infections, with great variability between studies. Most of the studies were about Herpes Simplex Virus (HSV). The outcome measure that was most commonly used was the presence of HSV infection diagnosed based on a combination of suggestive clinical presentation with a positive laboratory result. HSV culture was the most commonly reported laboratory outcome measure. Acyclovir and valacyclovir were consistently reported to be efficacious in the management of oral herpetic infections. No new data on the quality of life and economic aspects was found. CONCLUSIONS: Considering the variability in outcome measures reported to assess oral herpetic infections the researcher should select carefully the appropriate measures based on the objective of the study. Acyclovir and valacyclovir are effective in the management of oral herpetic infections in patients receiving treatment for cancer. Studies on newer anti-viral drugs may be useful to address the issue of anti-viral resistance.

TLR4-Dependent Claudin-1 Internalization and Secretagogue-Mediated Chloride Secretion Regulate Irinotecan-Induced Diarrhea.

We have previously shown increased intestinal permeability, to 4-kDa FITC-dextran, in BALB/c mice treated with irinotecan. Importantly, genetic deletion of Toll-like receptor 4 (TLR4; Tlr4-/-) protected against loss of barrier function, indicating that TLR4 is critical in tight junction regulation. The current study aimed (i) to determine the molecular characteristics of intestinal tight junctions in wild-type and Tlr4-/- BALB/c mice and (ii) to characterize the secretory profile of the distal colon. Forty-two female wild-type and 42 Tlr4-/- BALB/c mice weighing between 18 and 25 g received a single 270 mg/kg [intraperitoneal (i.p.)] dose of irinotecan hydrochloride or vehicle control and were killed at 6, 24, 48, 72, and 96 hours. The secretory profile of the distal colon, following carbachol and forksolin, was assessed using Ussing chambers at all time points. Tight junction integrity was assessed at 24 hours, when peak intestinal permeability and diarrhea were reported, using immunofluorescence, Western blotting, and RT-PCR. Irinotecan caused internalization of claudin-1 with focal lesions of ZO-1 and occludin proteolysis in the ileum and colon of wild-type mice. Tlr4-/- mice maintained phenotypically normal tight junctions. Baseline conductance, a measure of paracellular permeability, was increased in irinotecan-treated wild-type mice at 24 hours (53.19 ± 6.46 S/cm2; P = 0.0008). No change was seen in Tlr4-/- mice. Increased carbachol-induced chloride secretion was seen in irinotecan-treated wild-type and Tlr4-/- mice at 24 hours (wild-type: 100.35 ± 18.37 µA/cm2; P = 0.022; Tlr4-/-: 102.72 ± 18.80 µA/cm2; P = 0.023). Results suggest that TLR4-dependent claudin-1 internalization and secondary anion secretion contribute to irinotecan-induced diarrhea. Mol Cancer Ther; 15(11); 2767-79. ©2016 AACR.

Cytokine-mediated blood brain barrier disruption as a conduit for cancer/chemotherapy-associated neurotoxicity and cognitive dysfunction.

Neurotoxicity is a common side effect of chemotherapy treatment, with unclear molecular mechanisms. Clinical studies suggest that the most frequent neurotoxic adverse events affect memory and learning, attention, concentration, processing speeds and executive function. Emerging preclinical research points toward direct cellular toxicity and induction of neuroinflammation as key drivers of neurotoxicity and subsequent cognitive impairment. Emerging data now show detectable levels of some chemotherapeutic agents within the CNS, indicating potential disruption of blood brain barrier integrity or transport mechanisms. Blood brain barrier disruption is a key aspect of many neurocognitive disorders, particularly those characterized by a proinflammatory state. Importantly, many proinflammatory mediators able to modulate the blood brain barrier are generated by tissues and organs that are targets for chemotherapy-associated toxicities. This review therefore aims to explore the hypothesis that peripherally derived inflammatory cytokines disrupt blood brain barrier permeability, thereby increasing direct access of chemotherapeutic agents into the CNS to facilitate neuroinflammation and central neurotoxicity.

Irinotecan-Induced Gastrointestinal Dysfunction and Pain Are Mediated by Common TLR4-Dependent Mechanisms.

Strong epidemiological data indicate that chemotherapy-induced gut toxicity and pain occur in parallel, indicating common underlying mechanisms. We have recently outlined evidence suggesting that TLR4 signaling may contribute to both side effects. We therefore aimed to determine if genetic deletion of TLR4 improves chemotherapy-induced gut toxicity and pain. Forty-two female wild-type (WT) and 42 Tlr4 null (-/-) BALB/c mice weighing between 18 and 25 g (10-13 weeks) received a single 270 mg/kg (i.p.) dose of irinotecan hydrochloride or vehicle control and were killed at 6, 24, 48, 72, and 96 hours. Bacterial sequencing was conducted on cecal samples of control animals to determine the gut microbiome profile. Gut toxicity was assessed using validated clinical and histopathologic markers, permeability assays, and inflammatory markers. Chemotherapy-induced pain was assessed using the validated rodent facial grimace criteria, as well as immunologic markers of glial activation in the lumbar spinal cord. TLR4 deletion attenuated irinotecan-induced gut toxicity, with improvements in weight loss (P = 0.0003) and diarrhea (P < 0.0001). Crypt apoptosis was significantly decreased in BALB/c-Tlr4(-/-billy) mice (P < 0.0001), correlating with lower mucosal injury scores (P < 0.005). Intestinal permeability to FITC-dextran (4 kDa) and LPS translocation was greater in WT mice than in BALB/c-Tlr4(-/-billy) (P = 0.01 and P < 0.0001, respectively). GFAP staining in the lumbar spinal cord, indicative of astrocytic activation, was increased at 6 and 72 hours in WT mice compared with BALB/c-Tlr4(-/-billy) mice (P = 0.008, P = 0.01). These data indicate that TLR4 is uniquely positioned to mediate irinotecan-induced gut toxicity and pain, highlighting the possibility of a targetable gut/CNS axis for improved toxicity outcomes. Mol Cancer Ther; 15(6); 1376-86. ©2016 AACR.

A novel in vitro platform for the study of SN38-induced mucosal damage and the development of Toll-like receptor 4-targeted therapeutic options.

Tight junction and epithelial barrier disruption is a common trait of many gastrointestinal pathologies, including chemotherapy-induced gut toxicity. Currently, there are no validated in vitro models suitable for the study of chemotherapy-induced mucosal damage that allow paralleled functional and structural analyses of tight junction integrity. We therefore aimed to determine if a transparent, polyester membrane insert supports a polarized T84 monolayer with the phenotypically normal tight junctions. T84 cells (passage 5-15) were seeded into either 0.6 cm(2), 0.4 µm pore mixed-cellulose transwell hanging inserts or 1.12 cm(2), 0.4 µm pore polyester transwell inserts at varying densities. Transepithelial electrical resistance was measured daily to assess barrier formation. Immunofluoresence for key tight junction proteins (occludin, zonular occludens-1, claudin-1) and transmission electron microscopy were performed to assess tight junction integrity, organelle distribution, and polarity. Reverse transcription-polymerase chain reaction was performed to determine expression of toll-like receptor 4 (TLR4). Liquid chromatography was also conducted to assess SN38 degradation in this model. Polyester membrane inserts support a polarized T84 phenotype with functional tight junctions in vitro. Transmission electron microscopy indicated polarity, with apico-laterally located tight junctions. Immunofluorescence showed membranous staining for all tight junction proteins. No internalization was evident. T84 cells expressed TLR4, although this was significantly lower than levels seen in HT29 cells (P = .0377). SN38 underwent more rapid degradation in the presence of cells (-76.04 ± 1.86%) compared to blank membrane (-48.39 ± 4.01%), indicating metabolic processes. Polyester membrane inserts provide a novel platform for paralleled functional and structural analysis of tight junction integrity in T84 monolayers. T84 cells exhibit the unique ability to metabolize SN38 as well as expressing TLR4, making this an excellent platform to study clinically relevant therapeutic interventions for SN38-induced mucosal damage by targeting TLR4.

Tight junction defects are seen in the buccal mucosa of patients receiving standard dose chemotherapy for cancer.

PURPOSE: Oral mucositis is one of the most common and debilitating side effects of chemotherapy treatment. Patients are often unable to eat and drink, which can lead to poor clinical outcomes and extensive resource utilisation. The primary aim of this study was to determine the molecular integrity of oral epithelial tight junctions in patients undergoing chemotherapy. The secondary aim was to correlate these changes with proinflammatory cytokines and matrix metalloproteinase profiles. METHODS: Patients (n = 23) were recruited from the Royal Adelaide Hospital between 2000 and 2003. Reach patient underwent two oral buccal mucosa biopsies (4 mm): one prior to chemotherapy treatment and a second one after chemotherapy treatment. Oral buccal mucosa biopsies were also taken from seven healthy volunteers with no history of cancer, chemo- or radiotherapy treatment or inflammatory disorders. Routine haematoxylin and eosin staining was performed to determine epithelial thickness. Immunohistochemical staining was performed for claudin-1, zonular occludens-1, occludin, interleukin-1ß, tumour necrosis factor, interleukin-6, matrix metalloproteinase-2 and metalloproteinase-9. RESULTS: Patients receiving standard dose chemotherapy had significant epithelial atrophy. Elevations in all cytokines and matrix metalloproteinases were seen, with significant lamina propria staining for interleukin-6 and tumour necrosis factor. Matrix metalloproteinase-2 appeared most upregulated within the oral epithelium. These changes coincided with altered tight junction staining properties. Changes in the staining intensity and localisation were both noted, with clear cytoplasmic staining for zonular occludens-1 and claudin-1 in patients treated with chemotherapy. CONCLUSIONS: Chemotherapy causes defects in oral tight junctions, coupled with altered cytokine and matrix metalloproteinase profiles. Tight junction disruption in the epithelium may contribute to ulcer development or lead to poor tissue integrity, and the timing of these events may be a target for preventative treatment.