Diabetes and oral tumors in Hungary: epidemiological correlations

Metformin Treatment Is Not Associated with Altered PD-L1 Expression in Diabetic Patients with Oral Squamous Cell Carcinoma

Background: The anti-neoplastic activity of metformin is a subject of current debate. Preclinical data have suggested that metformin enhances PD-L1 anti-tumor effects in various cancer entities by decreasing insulin levels and inducing energetic stress. However, its impact on PD-L1 expression remains unclear in a clinical setting. Therefore, we aim to investigate the impact of metformin treatment in type 2 diabetes mellitus (DM) patients on PD-L1 expression in patients with oral squamous cell carcinoma (OSCC). Methods: We performed a retrospective analysis of patients with DM and OSCC treated at our tertiary referral center over a period of 12 years. The tumor proportion score (TPS), immune cell score (IC), and combined positive score (CPS) were used to quantify PD-L1 expression. PD-L1 expression of patients receiving metformin was compared to a control group without metformin prescription. Results: A total of 68 patients diagnosed with OSCC and DM were analyzed, with 24 receiving and 44 not receiving metformin therapy. No statistically significant differences were identified between the metformin and non-metformin groups for any of the scores (TPS: p = 0.818; IC: p = 0.748; CPS: p = 0.387). Conclusions: In contrast to previous studies, we could not find significant differences in PD-L1 expression between patients with and without metformin intake. Further research needs to shed light on the exact mechanism of metformin in different tumor entities. A comprehensive understanding of metformin's role in cancer therapy could provide valuable insights for potential use of metformin as an adjuvant treatment to immune checkpoint therapy.

Unraveling the potential effects of non-synonymous single nucleotide polymorphisms (nsSNPs) on the Protein structure and function of the human SLC30A8 gene on type 2 diabetes and colorectal cancer: An In silico approach

Background and aims

The single nucleotide polymorphisms (SNPs) in SLC30A8 gene have been recognized as contributing to type 2 diabetes (T2D) susceptibility and colorectal cancer. This study aims to predict the structural stability, and functional impacts on variations in non-synonymous SNPs (nsSNPs) in the human SLC30A8 gene using various computational techniques.

Materials and methods

Several in silico tools, including SIFT, Predict-SNP, SNPs&GO, MAPP, SNAP2, PhD-SNP, PANTHER, PolyPhen-1,PolyPhen-2, I-Mutant 2.0, and MUpro, have been used in our study.

Results

After data analysis, out of 336 missenses, the eight nsSNPs, namely R138Q, I141N, W136G, I349N, L303R, E140A, W306C, and L308Q, were discovered by ConSurf to be in highly conserved regions, which could affect the stability of their proteins. Project HOPE determines any significant molecular effects on the structure and function of eight mutated proteins and the three-dimensional (3D) structures of these proteins. The two pharmacologically significant compounds, Luzonoid B and Roseoside demonstrate strong binding affinity to the mutant proteins, and they are more efficient in inhibiting them than the typical SLC30A8 protein using Autodock Vina and Chimera. Increased binding affinity to mutant SLC30A8 proteins has been determined not to influence drug resistance. Ultimately, the Kaplan-Meier plotter study revealed that alterations in SLC30A8 gene expression notably affect the survival rates of patients with various cancer types.

Conclusion

Finally, the study found eight highly deleterious missense nsSNPs in the SLC30A8 gene that can be helpful for further proteomic and genomic studies for T2D and colorectal cancer diagnosis. These findings also pave the way for personalized treatments using biomarkers and more effective healthcare strategies.

Prognostic value of diabetes and metformin use in a real-life population of head and neck cancer patients

Introduction

Head and neck carcinoma (HNC) is a disease with a poor prognosis despite currently available treatments. The management of patients with this tumor is often complicated by several comorbidities. Among these, diabetes is the second most frequent and its influence on the prognosis is not known.

Methods

In this work, we collected data on progression free survival (PFS) and overall survival (OS) of one hundred twenty-three patients with HNC who received biweekly cetuximab maintenance treatment after first-line chemotherapy. We then compared the survival of nondiabetic patients versus diabetics' one.

Results

Surprisingly, both PFS (4 vs. 5 months, HR 2.297, p < 0.0001) and OS (7 vs. 10 months, HR 3.138, p < 0.0001) were in favor of diabetic patients, even after excluding other clinical confounding factors. In addition, we also studied survivals in patients taking metformin, a widely used oral antidiabetic drug that has demonstrated antitumor efficacy in some cancers. Indeed, diabetic patients taking metformin had better PFS and OS than those not taking it, 7 vs. 5 months (HR 0.56, p = 0.0187) and 11 vs. 8.5 months (HR 0.53, p = 0.017), respectively.

Discussion

In conclusion, real-world outcomes of biweekly cetuximab maintenance remain comparable to clinical trials. The prognostic role of diabetes and metformin was confirmed to be significant in our series, but further prospective studies are needed for a definitive evaluation.

Fatty Liver and Risk of Head and Neck Cancer in Type 2 Diabetes Mellitus: A Nationwide Cohort Study

This study is aimed at investigating the association between NAFLD and the risk of HNC separately based on cancer site using a large population-based cohort of patients with T2DM. The data used in this population-based retrospective cohort study were provided by the Korean National Health Insurance Service. The Cox proportional hazards model was used to estimate multivariable adjusted hazard ratios and 95% CIs for the association of the fatty liver index (FLI) and the risk of HNC. During the mean 6.9 years of follow-up, approximately 25.4% of the study cohort had NAFLD, defined as an FLI ≥60. A total of 3543 HNC cases were identified. Overall, patients with a higher FLI had a significantly higher risk of HNC in the oral cavity, pharynx, and larynx compared with patients with an FLI <30. An association was not observed between salivary gland cancer and FLI. There was no association between obesity and HNC. However, obese patients showed a lower risk of cancer for the oral cavity (p = 0.040), pharynx (p = 0.009), and larynx (p < 0.001) than non-obese patients with the same FLI level. Neither obesity nor smoking affected the association between FLI- and HNC-risk in stratified analyses. In T2DM patients, NAFLD was associated with an increased risk of developing HNC in the oral cavity, pharynx, and larynx, but not in the salivary gland.

The neuropeptide substance P/neurokinin-1 receptor system and diabetes: From mechanism to therapy

Diabetes is a significant public health issue known as the world's fastest-growing disease condition. It is characterized by persistent hyperglycemia and subsequent chronic complications leading to organ dysfunction and, ultimately, the failure of target organs. Substance P (SP) is an undecapeptide that belongs to the family of tachykinin (TK) peptides. The SP-mediated activation of the neurokinin 1 receptor (NK1R) regulates many pathophysiological processes in the body. There is also a relation between the SP/NK1R system and diabetic processes. Importantly, deregulated expression of SP has been reported in diabetes and diabetes-associated chronic complications. SP can induce both diabetogenic and antidiabetogenic effects and thus affect the pathology of diabetes destructively or protectively. Here, we review the current knowledge of the functional relevance of the SP/NK1R system in diabetes pathogenesis and its exploitation for diabetes therapy. A comprehensive understanding of the role of the SP/NK1R system in diabetes is expected to shed further light on developing new therapeutic possibilities for diabetes and its associated chronic conditions.

Impact of hyperglycemia on the expression of GLUT1 during oral carcinogenesis in rats

BACKGROUND

On the background of the epidemiological link between diabetes and oral cancer, the present study aimed to analyze the potential involvement of selected glucose transporters (GLUT1/GLUT3/GLUT4), if any, in such putative association.

METHODS AND RESULTS

Oral carcinogenesis was induced by 4-nitroquinoline N-oxide in 10 non-diabetic and 10 diabetic rats; 8 non-diabetic and 7 diabetic rats served as controls. Expressions of selected GLUTs at mRNA and protein levels were analyzed in oral tissue (normal/lesion) by quantitative real-time PCR and immunohistochemistry respectively. Premalignant lesions (hyperplasia/dysplasia/carcinoma-in-situ) appeared on tongues of carcinogen-treated animals. Significant increase of GLUT1mRNA level was seen from normal to lesion tongues, along increasing lesion grades (from hyperplasia/mild dysplasia to moderate/severe dysplasia) and in lesions induced under hyperglycemic condition than that induced under normoglycemic one; a similar trend was found in transcript variant-1 of GLUT1, but not in variant-2. GLUT3 and GLUT4 mRNA levels were comparable among lesions irrespective of grades and glycemic status. Concordant to mRNA level, overall expression of GLUT1 protein was higher in tongue lesions in presence of hyperglycemia than in absence of such condition; non-lesion portions of tongues exposed to carcinogen showed a similar trend. Moreover in carcinogen-treated groups, non-lesion and lesion portions of tongues under hyperglycemic condition showed predominantly membranous expression for GLUT1 which was again significantly higher than equivalent portions of tongue under normoglycemic condition.

CONCLUSION

Hyperglycemia seemed to favor GLUT1 over-expression and membrane localization of the protein during oral carcinogenesis. GLUT1 transcript variant-1 appeared to be more important than variant-2 in disease pathogenesis.

Type 2 diabetes mellitus and risk of head and neck cancer subtypes: a systematic review and meta-analysis of observational studies

AIMS

The association between type 2 diabetes mellitus (T2DM) and risk of head and neck cancer (HNC) remains unclear. This study aims to perform a system review and meta-analysis to explore this relationship.

METHODS

PubMed, Web of Science, and Embase databases were searched for studies published up to July 31, 2020, regarding the association between T2DM and HNC risk. A random-effects model was utilized to calculate summary relative risks (RRs) with corresponding 95% confidence intervals (CIs).

RESULTS

Fourteen case-control studies and thirteen cohort studies were included in our analysis. We observed a weak association between T2DM and risk of HNC overall, but there was no statistical significance (RR, 1.04; 95% CI, 0.88-1.23; I² = 83.2%). Interestingly, there was a strong association in East Asia (RR, 1.46; 95% CI, 1.21-1.77; I² = 36.6%). For HNC subtypes, T2DM conferred a significantly elevated risk in oral cancer (RR, 1.22; 95% CI, 1.01-1.47; I² = 89.0%). However, in subgroup analyses of smoking, alcohol use, and body mass index (BMI)/obesity adjustments, the association between T2DM and oral cancer risk became insignificant. In addition, T2DM was not associated with a statistically elevated risk of pharyngeal cancer (RR, 1.18; 95% CI, 0.94-1.49; I² = 72.9%) and laryngeal cancer (RR, 1.03; 95% CI, 0.88-1.22; I² = 71.2%).

CONCLUSIONS

This meta-analysis indicates that T2DM is associated with an increased risk of HNC in East Asia. As for site-specific cancer types, the risk of oral cancer was significantly increased in T2DM patients, which appear to be mediated or confounded by smoking, alcohol use, or BMI/obesity.

Survival and glycemic control in patients with co-existing squamous cell carcinoma and diabetes mellitus

Aim:

This study examined the impact of diabetes mellitus (DM) on survival in squamous cell carcinoma (SCC) patients, and the impact of SCC on glycemic control.

Materials & methods:

Patients with newly diagnosed SCC with and without DM were matched 1:1 (2007–2017). Overall survival and recurrence-free survival were estimated using the Kaplan–Meier method. Hemoglobin A_1c (HbA_1c) and glucose level during the year following cancer diagnosis were compared using mixed models.

Results:

HbA_1c decreased over time in DM patients (p = 0.04). The 5-year overall survival was 61% in DM patients, compared with 78% in patients without DM (p = 0.004).

Conclusion:

The presence of co-existing DM adversely impacted survival in patients with SCC. SCC did not affect glycemic control.

The objective of this study was to identify the effect of diabetes mellitus (DM) on survival of patients with squamous cell carcinoma (SCC) and to determine whether SCC and its treatment affected glycemic control. We used an institutional cancer registry to identify 190 patients with SCC and grouped them by the presence (n = 95) or absence (n = 95) of DM. Patients were matched by age and year of SCC diagnosis. For individuals with SCC, DM did decrease survival rates, and the diagnosis of SCC did not affect glycemic control.

Effect of metabolic syndrome on incidence of oral potentially malignant disorder: a prospective cohort study in Taiwan

OBJECTIVES

We aimed to assess the effect of metabolic syndrome (MetS) on incident oral potentially malignant disorder (OPMD).

DESIGN

We conducted a prospective cohort study of the Changhua community-based integrated screening (CHCIS) programme and nationwide oral cancer screening programme during the period between 2005 and 2014.

SETTING

CHCIS, Taiwan.

PARTICIPANTS

We enrolled 17 590 participants aged 30 years and older.

MAIN OUTCOMES AND MEASURES

We assessed the impact of MetS on the outcome measured by incident OPMD.

RESULTS

The incidences of OPMD among subjects with and without MetS were 7.68 ‰ and 5.38 ‰, respectively. After adjusting for confounders, subjects with MetS exhibited a statistically greater risk of developing OPMD compared with those who were free of MetS by 33% (adjusted rate ratio, aRR=1.33, 95% CI 1.14 to 1.55). Individual components of MetS still remained significant, including central obesity (aRR=1.22, 95% CI 1.04 to 1.44), hypertriglyceridaemia (aRR=1.26, 95% CI 1.07 to 1.49) and hyperglycaemia (aRR=1.20, 95% CI 1.02 to 1.41). Central obesity and hypertriglyceridaemia were also statistically associated with a subtype of OPMD, namely, leukoplakia.

CONCLUSION

The temporal influence of MetS on the risk of incident OPMD was noted in our prospective cohort study. Therefore, promoting an MetS prevention and control programme might reduce the occurrence of OPMD and oral cancer.

Chronic disease comorbidity in patients with oral leukoplakia: A matched case-control study

OBJECTIVE

The purpose of this study was to investigate the presence of chronic diseases in patients with oral leukoplakia (OL) compared to controls matched for age group, gender, smoking and alcohol use.

SUBJECTS AND METHODS

This case-control study examined the general demographics, medical and social histories of 105 OL cases and 391 controls matched for age group, gender, tobacco and alcohol use. All OL cases were diagnosed based on both clinical and histopathological findings.

RESULTS

Chronic diseases were significantly associated with OL, namely dyslipidaemia (p < .0001), musculoskeletal diseases (p = .0101) and asthma (p = .0052). The use of ACE inhibitors (p = .0177), opioid analgesics (p = .0300), anticoagulants (p = .0055) and statins (p = .0010) was significantly associated with OL. Dyslipidaemia (p < .0001; odds ratio [95% CI]: 6.4 [3.5-11.6]) and asthma (p = .0110; odds ratio [95% CI]: 2.2 [1.2-4.0]) were identified as independent predictors of OL in multivariate analysis, both of which were significantly more common amongst cases than controls.

CONCLUSIONS

Results from this first Australian study suggest that dyslipidaemia and asthma may constitute independent predictors for the presence of OL. However, longitudinal studies are needed to ascertain the temporal relationship between OL and chronic disease comorbidity and the mechanisms underlying these associations.

Association of Diabetes with Oral Cancer- an Enigmatic Correlation

Introduction:

Association of diabetes mellitus (DM) with head and neck cancers (HNC) is still controversial. In some studies, diabetic patients had an increased risk of cancer at some HNC subsites like oral cancer, while in other studies this risk was decreased. So, the present study aims to evaluate the association of diabetes mellitus, oral cancer with and without metformin and the role of habits in association with DM and metformin in the etiology of oral cancer.

Materials and methods:

This study was undertaken in the Kamineni Institute of Dental Sciences in collaboration with MNJ Institute of Oncology and Regional Cancer Centre, Hyderabad. The study includes 2 main groups, they are 500 Oral cancer patients and Control group includes 500 age and gender-matched patients with habits without any oral precancerous lesion/conditions. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using unconditional logistic regression.

Results:

Out of 1000 subjects inverse relation of DM with oral cancer was observed. On comparison between oral cancer, diabetes and habits in study group and control group, decreased risk was observed with smokers (OR: 1.131and 95%CI: 0.68 -1.86) and non-chewers (OR: 2.43 and 95% CI: 1.31 - 4.49) and non-alcoholics (OR: 1.78 and 95% C.I:1.18 - 2.68). Metformin use among diabetic participants was associated with a decreased risk of oral cancer (OR: 0.51 and 95% C.I: 0.33 - 0.77). A negative association was observed in smokers (OR: 0.19 and 95% C.I.: 0.078 - 0.459), non-chewers (OR: 0.24 and 95% C.I : 0.11- 0.53) and non-alcoholics (OR: 0.46 and 95% C.I. : 0.29 - 0.727).

Conclusion:

Thus the present population based study results suggest an inverse association of DM and oral cancer with metformin and negative association of habits with DM and Metformin in etiology of oral cancer.

Diabetes and its Potential Impact on Head and Neck Oncogenesis

In recent years, the incidence of diabetes mellitus and cancer has increased sharply; indeed, these have become the two most important diseases threatening health and survival. Head and neck (HN) tumors are the sixth most common malignancies in humans. Numerous studies have shown that there are many common risk factors for diabetes mellitus and HN squamous cell carcinoma, including advanced age, poor diet and lifestyle, and environmental factors. However, the mechanism linking the two diseases has not been identified. A number of studies have shown that diabetes affects the development, metastasis, and prognosis of HN cancer, potentially through the associated hyperglycemia, hyperinsulinemia and insulin resistance, or chronic inflammation. More recent studies show that metformin, the first-line drug for the treatment of type 2 diabetes, can significantly reduce the risk of HN tumor development and reduce mortality in diabetic patients. Here, we review recent progress in the study of the relationship between diabetes mellitus and HN carcinogenesis, and its potential mechanisms, in order to provide a scientific basis for the early diagnosis and effective treatment of these diseases.

Logistic regression prediction model identify type 2 diabetes mellitus as a prognostic factor for human papillomavirus-16 associated head and neck squamous cell carcinoma

BACKGROUND

HPV-16-positive HNSCC and HPV-16-negative HNSCC have different clinical factors, representing distinct forms of cancers. The study aimed to identify patient-specific factors for HPV-16-positive HNSCC based on baseline clinical data.

METHOD

Factors associated with HPV-16-positive HNSCC were identified using the data from 210 patients diagnosed with HNSCC at University College of London Hospital between January 1, 2003, and April 30, 2015, inclusive. A series of models were developed using logistic regression methods, and the overall model fit was compared using Akaike Information Criterion. Survival analysis was carried with Cox proportional hazards model for survival-time outcomes. The survival time for individual patients was defined as the time from diagnosis of HNSCC to the date of death from any cause. For patients who did not die, they were censored at the end of study on April 30, 2015.

RESULTS

Of the 210 patients, 151 (72%) were found to have HPV-16-positive HNSCC. The logistic regression model showed that the prevalence of developing HPV-16-positive HNSCC was 3.79 times higher in patients with Type 2 Diabetes Mellitus (T2DM) (odd ratio [OR], 3.79; 95% CI, 1.70-8.44) than in those without T2DM, and 8.84 times higher in patients with history of primary HNSCC (OR, 8.84; 95% CI, 2.30-33.88) than in those without a history of primary HNSCC. HPV-16-positive HNSCC was also observed more in tonsils (OR, 4.02; 95% CL, 1.56-10.36) and less in non-alcohol drinker's oral cavity (OR, 0.14; 95% CI, 0.03-0.56). Furthermore, individual patients were followed-up for 1 to 13 years (median of 1 year). Patients with HPV-positive HNSCC had a median survival of 5 years (95% CI, 2.6-7.3 years). Among HPV-16-positive HNSCC cohort, T2DM was a risk for poorer prognosis (hazard ratio, 2.57; 95% Cl, 1.09-6.07), and had lower median survival of 3 years (95% CI, 1.8-4.1 years), as compared to 6 years (95% CI, 2.8-9.1 years) in non-T2DM.

CONCLUSIONS

Patient-specific factors for HPV-positive HNSCC are T2DM, history of primary HNSCC and tonsillar site. T2DM is associated with poorer prognosis. These findings suggest that it might be beneficial if routine HPV-16 screening is carried out in T2DM patients which can provide better therapeutic and management strategies.

Evaluating All Potential Oral Complications of Diabetes Mellitus

Diabetes mellitus (DM) is associated with several microvascular and macrovascular complications, such as retinopathy, nephropathy, neuropathy, and cardiovascular diseases. The pathogenesis of these complications is complex, and involves metabolic and hemodynamic disturbances, including hyperglycemia, insulin resistance, dyslipidemia, hypertension, and immune dysfunction. These disturbances initiate several damaging processes, such as increased reactive oxygen species (ROS) production, inflammation, and ischemia. These processes mainly exert their damaging effect on endothelial and nerve cells, hence the susceptibility of densely vascularized and innervated sites, such as the eyes, kidneys, and nerves. Since the oral cavity is also highly vascularized and innervated, oral complications can be expected as well. The relationship between DM and oral diseases has received considerable attention in the past few decades. However, most studies only focus on periodontitis, and still approach DM from the limited perspective of elevated blood glucose levels only. In this review, we will assess other potential oral complications as well, including: dental caries, dry mouth, oral mucosal lesions, oral cancer, taste disturbances, temporomandibular disorders, burning mouth syndrome, apical periodontitis, and peri-implant diseases. Each oral complication will be briefly introduced, followed by an assessment of the literature studying epidemiological associations with DM. We will also elaborate on pathogenic mechanisms that might explain associations between DM and oral complications. To do so, we aim to expand our perspective of DM by not only considering elevated blood glucose levels, but also including literature about the other important pathogenic mechanisms, such as insulin resistance, dyslipidemia, hypertension, and immune dysfunction.

Impact of oral potentially malignant disorder subtypes on all-cause and cause-specific mortality in males

OBJECTIVES

To quantify the effect of oral potentially malignant disorder (OPMD) subtypes on mortality from oral cancer and type 2 diabetes among areca nut chewers and/or cigarette smokers.

MATERIALS AND METHODS

A retrospective cohort design was devised to follow 14,749 men attending community-based screening program for oral cancer between 1998 and 2000 and followed until 2010. The Cox proportional hazards regression model was applied to assess the effect of OPMD on death.

RESULTS

A total of 1,291(8.75%) patients were detected as OPMD. Among those free of T2DM at baseline, the elevated risk for death from T2DM was noted for OSF (aHR = 3.62, 95% CI: 1.25-10.51) and erythroplakia (aHR = 5.01, 95% CI: 1.17-21.45). The elevated risk for all-cause death for OPMD was mainly explained by deaths from oral cancer and T2DM but not other causes of death.

CONCLUSIONS

Oral potentially malignant disorder, particularly OSF and erythroplakia, in male cigarette smokers and/or areca nut chewers led to an incremental elevated risk of T2DM mortality in the way of being distal to the occurrence of T2DM, implying that early detection and prevention of OPMD may not only reduce oral cancer mortality but also result in the reduction of T2DM mortality.

Current relevance of hypoxia in head and neck cancer

Head and Neck cancer (HNC) is a complex mix of cancers and one of the more common cancers with a relatively poor prognosis. One of the factors that may assist us in predicting survival and allow us to adjust our treatment strategies is the presence of tumor hypoxia. In this overview we aim to evaluate the current evidence and potential clinical relevance of tumor hypoxia in head and neck cancer according to an extensive search of current literature.An abundance of evidence and often contradictory evidence is found in the literature. Even the contradictory evidence and comparisons are difficult to judge as criteria and methodologies differ greatly, furthermore few prospective observational studies exist for verification of the pre-clinical studies. Despite these discrepancies there is clear evidence of associations between prognosis and poor tumor oxygenation biomarkers such as HIF-1α, GLUT-1 and lactate, though these associations are not exclusive. The use of genetic markers is expanding and will probably lead to significantly more and complex evidence. The lack of oxygenation in head and neck tumors is of paramount importance for the prediction of treatment outcomes and prognosis. Despite the wide array of conflicting evidence, the drive towards non-invasive prediction of tumor hypoxia should continue.

Prevalence of Oral Mucosal Disorders in Diabetes Mellitus Patients Compared with a Control Group

Chronic hyperglycemia is associated with impaired wound healing and higher susceptibility to infections. It is unclear whether patients with diabetes mellitus (DM) present more oral mucosal disorders compared to control groups. The objectives were to compare (a) the prevalence rates of oral mucosal disorders in the DM and non-DM population and (b) the prevalence rates of specific disorders in the DM and non-DM population. Full-text articles were included if they met the following inclusion criteria: (a) they must be original articles from scientific journals, (b) they must be only cross-sectional studies in English, (c) the prevalence of oral mucosal disorders in DM patients must be evaluated, (d) results must be compared with a healthy control group, and (e) oral mucosal disorders must be specified in DM and non-DM group. All studies showed higher prevalence of oral mucosal disorders in DM patients in relation to non-DM population: 45-88% in type 2 DM patients compared to 38.3-45% in non-DM groups and 44.7% in type 1 DM patients compared to 25% in non-DM population. Tongue alterations and denture stomatitis were the most frequent significant disorders observed. The quality assessment following the Joanna Briggs Institute (JBI) Prevalence Critical Appraisal Tool showed the low quality of the existing studies.

Dynamic cellular and molecular modulations of diabetes mediated head and neck carcinogenesis

Head and neck squamous cell carcinoma (HNSCC) is one of the most prevalent neoplasms worldwide. While numerous potent dietary insults were considered as oncogenic players for HNSCC development, the impact of metabolic imbalance was less emphasized during HNSCC carcinogenesis. Previous preclinical and epidemiological investigations showed that DM could possibly be correlated with greater incidence and poorer prognosis in HNSCC patients; however, the outcomes from different groups are contradictive and underlying mechanisms remains elusive. In the present study, the changes of cellular malignancy in response to prolonged glucose incubation in HNSCC cells were examined. The results demonstrated that hyperglycemia enhanced HNSCC cell malignancy over time through suppression of cell differentiation, promotion of cell motility, increased resistance to cisplatin, and up-regulation of the nutrient-sensing Akt/AMPK-mTORC1 pathway. Further analysis showed that a more aggressive tongue neoplastic progression was found under DM conditions compared to non-DM state whereas DM pathology led to a higher percentage of cervical lymph node metastasis and poorer prognosis in HNSCC patients. Taken together, the present study confirms that hyperglycemia and DM could enhance HNSCC malignancy and the outcomes are of great benefit in providing better anti-cancer treatment strategy for DM patients with HNSCC.

Multiple simultaneous primary oral squamous cell carcinomas: a previously unreported presentation

The simultaneous occurrence of a second oral squamous cell carcinoma, or in rare cases more, is well known, but to our knowledge, the presentation of 5 primary oral cancers at once has not previously been reported. We discuss this exceptional case and offer a possible explanation for its cause.

Type 2 diabetes mellitus and risk of oral cancer and precancerous lesions: a meta-analysis of observational studies

OBJECTIVE

Associations between type 2 diabetes mellitus (type 2 DM) and risk of oral cancer and precancerous lesions have been reported with controversial findings. We performed a meta-analysis to explore these associations.

METHODS

We identified studies by a literature search of MEDLINE and EMBASE through May 31, 2014, and by searching the reference lists of pertinent articles. Summary relative risk (SRR) with 95% confidence interval (CI) was calculated with a random-effects model. Between- study heterogeneity was assessed using the Cochran's Q and I(2) statistics.

RESULTS

A total of 13 studies (4 case-control and 9 cohort studies) on the association between type 2 DM and oral cancer were included. Overall analysis found that compared with non-diabetic individuals, individuals with type 2 DM had a significantly elevated incidence of oral cancer (SRR=1.15, 95% CI: 1.02-1.29; Pheterogeneity=0.277, I(2)=15.4%; 10 studies). Subgroup analyses found that duration of follow-up (⩾11years) significantly altered this positive association. Type 2 DM was associated with increased oral cancer mortality (SRR=1.41, 95% CI: 1.16-1.72; 4 studies). Meta-analysis of the four case-control studies showed a positive association between type 2 DM and risk of oral precancerous lesions (SRR=1.85, 95%CI: 1.23-2.80; Pheterogeneity=0.038, I(2)=57.5%). No significant public bias was found across these studies.

CONCLUSIONS

These findings of this meta-analysis indicate that compared with non-diabetic individuals, individuals with type 2 DM have an elevated risk of oral cancer and precancerous lesions development.

Restricting carbohydrates to fight head and neck cancer-is this realistic?

Head and neck cancers (HNCs) are aggressive tumors that typically demonstrate a high glycolytic rate, which results in resistance to cytotoxic therapy and poor prognosis. Due to their location these tumors specifically impair food intake and quality of life, so that prevention of weight loss through nutrition support becomes an important treatment goal. Dietary restriction of carbohydrates (CHOs) and their replacement with fat, mostly in form of a ketogenic diet (KD), have been suggested to accommodate for both the altered tumor cell metabolism and cancer-associated weight loss. In this review, I present three specific rationales for CHO restriction and nutritional ketosis as supportive treatment options for the HNC patient. These are (1) targeting the origin and specific aspects of tumor glycolysis; (2) protecting normal tissue from but sensitizing tumor tissue to radiation- and chemotherapy induced cell kill; (3) supporting body and muscle mass maintenance. While most of these benefits of CHO restriction apply to cancer in general, specific aspects of implementation are discussed in relation to HNC patients. While CHO restriction seems feasible in HNC patients the available evidence indicates that its role may extend beyond fighting malnutrition to fighting HNC itself.

Type 2 diabetes and edentulism as chronic co-morbid factors affecting Indian elderly: an overview

In past 50 years, type 2 diabetes has emerged as one of the major public health problem. India leads the world with the largest number of diabetic patients and has a huge elderly population. The present article discusses the effect of diabetes and edentulism on the overall general health of elderly. The prevalence of type 2 diabetes and edentulism in Indian elderly and their inter-relationship has been discussed. Dentists must provide optimum oral care with special attention towards comprehensive periodontal management and oral hygiene awareness among diabetics to prevent tooth loss. Dental and medical professionals can improve patient management of the oral and overall effects of diabetes by implementing various awareness programs; organizing camps; distributing informative pamphlets and dietary counseling. Dentists can detect undiagnosed cases of diabetes and refer patients to physicians for further evaluation and management.

Manifestações bucais em pacientes portadores de Diabetes Mellitus: uma revisão sistemática

OBJETIVO: O objetivo deste estudo foi realizar uma revisão sistemática da literatura sobre a associação entre o Diabetes Mellitus e as manifestações bucais. MÉTODO: Os métodos aplicados incluíram estratégia de busca na literatura e critérios de inclusão e exclusão para a seleção dos artigos a serem adotados. As bases de dados incluídas foram PubMed, SciElo, BBO e LILACS, até setembro de 2011. Os artigos selecionados investigaram a associação ou não do Diabetes Mellitus com manifestações bucais, excluindo a doença periodontal. RESULTADO: De 1164 artigos encontrados, 30 deles estavam de acordo com os critérios de inclusão, podendo permanecer no estudo. As manifestações bucais foram associadas com Diabetes Mellitus em 20 estudos. Os desfechos relacionados foram candidíase, hipossalivação, líquen plano bucal, estomatite por dentadura e lesões linguais. CONCLUSÃO: Os pacientes portadores de Diabetes Mellitus estão mais predispostos a apresentar candidíase e hipossalivação, podendo agravar muito determinadas condições de saúde bucal.

[Changes in the innervation of the taste buds in diabetic rats]

INTRODUCTION

Abnormal sensations such as pain and impairment of taste are symptoms of approximately 10% of patients having diabetes mellitus.

AIM

The aim of the study was to investigate and quantify the different neuropeptide containing nerve fibres in the vallate papilla of the diabetic rat.

METHODS

Immunohistochemical methods were used to study the changes of the number of different neuropeptide containing nerve terminals located in the vallate papillae in diabetic rats. Diabetes was induced in the rats with streptozotocin.

RESULTS

Two weeks after streptozotocin treatment the number of the substance P, galanin, vasoactive intestinal polypeptide and neuropeptide Y immunoreactive nerve terminals was significantly increased (p<0.05) in the tunica mucosa of the tongue. The number of the lymphocytes and mast cells was also increased significantly. Some of the immunoreactive nerve terminals were located in the lingual epithelium both intragemmally and extragemmally and were seen to comprise dense bundles in the lamina propria just beneath the epithelium. No taste cells were immunoreactive for any of the investigated peptides. Vasoactive intestinal polypeptide and neuropeptide Y immunoreactive nerve fibres were not detected in the taste buds. For weeks after streptozotocin administration the number of the substance P, calcitonin gene related peptide and galanin immunoreactive nerve terminals was decreased both intragemmally and intergemmally. In case of immediate insulin treatment, the number of the immunoreactive nerve terminals was similar to that of the controls, however, insulin treatment given 1 week later to diabetic rats produced a decreased number of nerve fibers. Morphometry revealed no significant difference in papilla size between the control and diabetic groups, but there were fewer taste buds (per papilla).

CONCLUSIONS

Increased number of immunoreactive nerve terminals and mast cells 2 weeks after the development of diabetes was the consequence of neurogenic inflammation which might cause vasoconstriction and lesions of the oral mucosa. Taste impairment, which developed 4 weeks after streptozotocin treatment could be caused by neuropathic defects and degeneration or morphological changes in the taste buds and nerve fibres.

Oral cancer in Taiwan: is diabetes a risk factor?

OBJECTIVES

The association between diabetes and oral cancer is rarely studied. We investigated the trends of oral cancer in the Taiwanese general population and the possible link with diabetes.

MATERIALS AND METHODS

The trend of age-standardized oral cancer incidence in 1979-2007 in Taiwan was calculated from the Taiwan Cancer Registry database. A total of 494,817 men and 503,723 women without oral cancer from a random sample of 1,000,000 individuals covered by the National Health Insurance were followed up from 2003 to 2005. Cox regression evaluated the adjusted relative risk considering potential detection bias and covariates.

RESULTS

The trends increased significantly in both sexes. Diabetic patients had a higher chance of oral cancer detection because they more frequently visited related medical professionals. Although diabetes status and duration were significantly associated with oral cancer in unadjusted models, none was significant after multivariable adjustment. For comorbidities, chronic obstructive pulmonary disease (a surrogate for smoking) and alcohol-related diagnoses were significant for men, and hypertension and alcohol-related diagnoses were significant for women. Additionally, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers and insulin were significant with relative risk (95 % confidence interval) of 1.642 (1.174-2.295) and 2.136 (1.003-4.547), respectively, in men.

CONCLUSIONS

Oral cancer is increasing in Taiwan. Diabetes is not a risk factor after multivariable adjustment.

CLINICAL RELEVANCE

The increasing trend of oral cancer may not be ascribed to diabetes. The association between oral cancer and some comorbidities and medications requires confirmation and may provide strategies for the prevention of oral cancer.

A review of risk factors for oral cavity cancer: the importance of a standardized case definition

The aim of this work is to review the literature on risk factors of oral cavity cancer with a special attention to the definition of the cases, in order to highlight special features of these cancers and of their subsites. PubMed database was systematically searched to access relevant articles published between 1980 and 2010. Reference lists of selected papers were examined to identify further articles. One hundred and two studies met the inclusion criteria. Their results were difficult to compare because of the lack of uniformity in defining oral cavity. In addition, few studies examined risk factors other than alcohol and tobacco, and studies differentiating between subsites were rare. Despite these limitations, some characteristics of oral cavity cancers may be emphasized: smoked tobacco seems to be a stronger risk factor for oral cavity cancer than alcohol, and the floor of the mouth seems to be more sensitive to the harmful effects of alcohol and smoked tobacco. Studies limited strictly to oral cavity cancers and distinguishing between subsites are needed to better understand the aetiology of these cancers, and better define risk groups to target prevention efforts and screening.

[Interactions of insulin and estrogen in the regulation of cell proliferation and carcinogenesis]

Equilibrium of sexual steroids and metabolic processes has close correlations. Insulin is a potent regulator of human sexual steroid hormone production and modulates their signals at receptor level. Insulin resistance and excessive insulin production provoke hyperandrogenism and estrogen deficiency in women resulting not only in anovulatory dysfunction but also a high risk for cardiovascular diseases and cancer. Physiologic functions of all female organs have higher estrogen demand as compared with men. In healthy women estrogen predominance against androgens is a favor in their reproductive period, which means a strong defense against insulin resistance and its complications. However, in postmenopausal cases the increasing prevalence of insulin resistance and type-2 diabetes associated with estrogen deficiency and androgen excess, result in a gender specific higher risk for precancerous lesions and cancer as compared with men. Estrogen has beneficial effect on the energy metabolism, glucose homeostasis and on the lipid metabolism of liver and of peripheral tissues as well. A moderate or severe decrease in serum estrogen level enhances the prevalence of insulin resistant states. In premenopausal women long or irregular menstrual cycles are predictors for the risk of insulin resistance and type-2 diabetes. Moreover, in postmenopausal estrogen deficient cases elevated fasting glucose, increased body weight and abdominal fat deposition are often observed progressively with age in correlation with an impaired glucose tolerance. In the rare cases of estrogen deficient men severe type-2 diabetes seems to be a characteristic complication. Upon becoming familiar with the cancer risk of insulin resistance and estrogen deficiency, there would be plenty of possibilities for primary cancer prevention. In patients with cancer the treatment of hormonal and metabolic disturbances may become effective adjuvant therapy.

Interplay between insulin resistance and estrogen deficiency as co- activators in carcinogenesis

Both insulin resistance and estrogen deficiency result in complex metabolic disorder based mainly on defective cellular glucose uptake and on an atherogenic serum lipid profile. These alterations may be regarded as high risks for several life-threatening human diseases, such as type-2 diabetes, cardiovascular lesions and malignancies. Insulin resistance and estrogen deficiency are concomitant disorders with mutual interrelationship. Insulin resistance and the compensatory hyperinsulinemia provoke increased androgen synthesis at the expense of decreased estrogen production. Similarly, a moderate or severe decrease in serum estrogen levels enhances the prevalence of insulin resistant states both in men and women. Healthy premenopausal women enjoy the defensive effect of estrogens against metabolic and hormonal disorders. However, even a slight decrease in their circulatory estrogen levels associated with insulin resistance may increase the risk for cancers, particularly in the organs having high estrogen demand (breast, endometrium and ovary). On the other hand, postmenopausal state with profound estrogen deficiency confers high risk for cancers in different organs with either high or moderate estrogen demand. After menopause, hormone replacement therapy improves insulin sensitivity and decreases the enhanced inclination to malignancies in postmenopausal women. Recognition of the thorough interplay between insulin resistance and estrogen deficiency may illuminate many apparently controversial experimental and clinical findings concerning cancer development and therapeutic possibilities. Moreover, their interactions in the initiation and progression of human malignancies may supply new strategies in primary cancer prevention and cancer cure.

The prevalence of median rhomboid glossitis in diabetic patients: a case-control study

BACKGROUND

Diabetes mellitus (DM) is one of the most common disorders of endocrine glands which has a worldwide distribution and is a risk factor for oral pathology so; the purpose of the present study was to investigate the association between median rhomboid glossitis (MRG) and DM.

METHODS

We examined 202 Iranian patients with DM aged 10-86 years and 261 healthy subjects aged 10-28 years and the diagnosis of MRG was made based on clinical features.

RESULTS

The examination indicated that 13 (6.43%) diabetic patients and 4 (1.53%) of control group had MRG.There was a significant difference in the prevalence of MRG, between patients and control group. MRG showed no association with other variables (age, sex, duration of DM, drugs, FBS, A1C).

CONCLUSION

In the present study the prevalence of MRG in diabetics was much higher than that of controls.

Association between metabolic syndrome and oral pre-malignancy: a community- and population-based study (KCIS No. 28)

To elucidate the effect of metabolic syndrome (MetS) on oral pre-malignancy (OPM) and also to examine whether the effect is independent of areca nut chewing. We enrolled a total of 79,940 subjects aged 20 years or older undergoing both oral mucous examination and health check-up for MetS within the Keelung Community-based Integrated Screening program between 2003 and 2008. We identified 368 leukoplakia, 72 erythroleukoplakia, and 69 oral submucous fibrosis. The multi-variable logistic regression was used to assess the association between MetS and OPM with adjustment of age, gender, areca nut chewing, smoking, and alcohol drinking. Subjects with MetS were at increased risk for OPM (adjusted odds ratio (aOR)=1.68, 95% confidence interval (CI): 1.39-2.04) compared with those without MetS after taking all explanatory factors into account. Among the five components of MetS, subjects with hypertriglyceride (aOR=1.43, 95% CI: 1.17-1.75) and hyperglycemia (aOR=1.30, 95% CI: 1.02-1.67) had higher risk of presenting OPM compared with those within normal ranges. The association between MetS and OPM still persisted even in non-chewers (aOR=1.85, 95% CI: 1.42-2.40) while other risk factors were controlled. We demonstrate a positive association between MetS and OPM, which is independent of areca nut chewing and other confounding factors. This finding provides an insight into a new direction of preventing OPM in contrast to conventional viewpoint focusing on the most important factor of area nut chewing.

Decreased oral cancer risk by moderate alcohol consumption in non-smoker postmenopausal women

OBJECTIVE

Alcohol consumption is a strong risk factor for oral cancer however; an ambiguous biphasic impact of moderate and excessive alcohol intake on the risk of upper aerodigestive tract cancers has also been published. The aim of the present study was to clarify the dose-related risk of alcohol consumption for oral cancer, in male and female cases.

MATERIALS AND METHODS

Six-hundred and eight non-smoker patients (466 males and 142 females) with squamous cell oral carcinomas (OCs) and 406 non-smoker tumor free controls (264 males and 142 females) were included into the study. Data of three groups; abstinent cases, moderate and excessive alcohol consumers were recorded according to the drinking habits of both OC cases and their controls. Blood glucose levels in male and female cases and menopausal state of women were also registered.

RESULTS

Mean age of female patients was significantly higher than of male cases (p<0.01). Excessive alcohol consumption was a strong risk factor for both sexes, however moderate alcohol intake proved to be an OC risk for men (OR: 1.4) and decreased the OC risk for women (OR: 0.7). Elevated blood glucose level proved to be an OC risk factor for the predominantly postmenopausal women (OR: 1.6), whereas did not affect the OC risk among men.

CONCLUSION

The presented findings are controversial to the hypothesis that women are more vulnerable to alcohol-induced carcinogenesis as compared with men. Increased insulin sensitivity and higher estrogen levels are advantageous systemic effects of moderate ethanol intake and they might reduce the risk for OC in postmenopausal women.

Diabetes mellitus and oral mucosa alterations: prevalence and risk factors

AIMS

To investigate the prevalence of oral mucosa alterations in patients with type 2 diabetes and to identify possible risk factors related to oral mucosa alterations.

METHODS

146 patients with type 2 diabetes and 111 age- and gender-matched healthy controls subjects were consecutively recruited from Araraquara School of Dentistry to answer a structured questionnaire designed to collect demographic data as well as current and former history of diabetes. Clinical examination of the oral mucosa was carried out by a stomatologist.

RESULTS

A higher prevalence of oral mucosa alterations was found in patients with diabetes than in patients without diabetes (p<0.001), with significant difference to development conditions (p<0.0001), potentially malignant disorders (p<0.0001) and fungal infections (p<0.05). In the multiple logistic regression, diabetes (odds ratio 9.9 IC 5.11-19.16) and smoking habit (odds ratio 3.17 IC 1.42-7.12) increased the odds of oral mucosa alterations significantly.

CONCLUSIONS

Patients with diabetes mellitus not only showed an increased prevalence of oral mucosa alterations but also a significant percentage of potentially malignant disorders. These findings elucidate the necessity of regular clinical examination to ensure early diagnosis and prompt management of oral mucosa lesions in patients with diabetes.

[Antidiabetic therapy--a new possibility in the complex therapy of cancer?]

Nowadays the lack of exercise and improper eating habits are main characteristics of modern life style. This favors not only formation of type 2 diabetes or cardiovascular diseases, but also increaseas the incidence and prevalence of malignant tumors. Today there are many epidemiologic trials that demonstrate the connection between type 2 diabetes and formation of several malignomas. Its cause should be searched in common paths of pathologic processes. One of this is the birth of hyperinsulinsulinemia, which accompanies insulin resistance. Hyperinsulinemia of the host leads to increased glucose uptake in the highly insuline sensitive tumor cells which supports tumor growth. This makes type 2 diabetes a metabolic state favoring tumor formation, suggesting a potential application of oral insulin sensitizers in cancer therapy. Currently several international trials are testing the anti-tumor activity of metformin and thiazolidinedions (TZD). Besides this, encouraging results were obtained with the use of anti-IGFR antibodies in the treatment of tumors. A common therapy of diabetes and tumor may lead to new possibilities in the treatment of malignant tumor diseases. By doing this we could be able to weaken the tumor and strengthen the body, enabling it to fight against cancer. Bánhegyi RJ, Rus-Gal PO, Nagy AK, Martyin T, Varga R, Pikó B. Correlation between type 2 diabetes and malignant tumors - new possibilities in the complex therapy of cancers?

Oral mucosal lesions in non oral habit diabetic patients and association of diabetes mellitus with oral precancerous lesions

AIMS

This study was aimed to determine the prevalence of oral mucosal lesions (OML) in patients with diabetes mellitus (DM) and non-diabetic subjects without any oral habits and to investigate the association of DM with oral precancerous lesions.

METHODS

This cross-sectional study involved 420 diabetic and 420 non-diabetic control subjects without any oral habits. Detailed oral examination was performed based on international criteria.

RESULTS

A significantly greater proportion of subjects with DM (45%) had one or more OML in comparison to non-diabetics (38.3%). Patients with DM showed a significantly greater prevalence of geographic tongue, denture stomatitis and angular cheilitis than non-diabetics (p<0.05). The results also showed an association between occurrence of one or more OML and metabolic control of diabetic patients (p<0.05). For precancerous lesions, lichen planus was found in two diabetic patients while none of controls had any precancerous lesion (p>0.05).

CONCLUSIONS

Prevalence of OML was significantly higher in diabetic patients than non-diabetics and this prevalence was associated with the metabolic control of the patients. However, no association was observed between DM and oral precancerous lesions.

Impact of diabetes mellitus on the prognosis of patients with oral squamous cell carcinoma: a retrospective cohort study

BACKGROUND

Diabetes mellitus (DM) is a prevalent chronic metabolic disease reported to affect the treatment outcomes of malignancies. This study explores the impact of diabetes on the prognosis of oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

Clinicopathological characteristics and survival in terms of overall survival (OS), recurrence-free survival (RFS), and cancer-specific survival (CSS) of patients with OSCC who underwent surgical intervention at the Taipei Veterans General Hospital between 2002 and 2005 were stratified by diabetic status and compared.

RESULTS

Patients with DM tend to have a lower OS, RFS, and CSS compared with nondiabetics (adjusted hazard ratio [HR] = 2.22, 2.42, and 2.16, respectively) even in less aggressive tumor stages (stage I and II). In advanced tumors, diabetic patients who were not prescribed adjuvant therapy had a significantly higher recurrence rate than nondiabetic patients (HR = 2.66). However, there was no significant difference in treatment outcome in patients with locally advanced tumors amenable to receive adjuvant therapy, even with the delayed initiation of adjuvant therapy in the DM group (49.1 +/- 22.3 days vs. 40.0 +/- 16.6 days, P = .04). DM was also associated with a higher frequency of perineural invasion (adjusted odds ratio [OR] = 2.53).

CONCLUSION

DM status could be a prognostic factor for OSCC, particularly for its effect in the survival and perineural invasion. Although diabetes-associated comorbidities may impair decision making toward less aggressive therapeutic modality, adjuvant treatment may be essential for DM patients to improve their survival.

Impact of diabetes mellitus on treatment outcomes in patients with nasopharyngeal cancer

BACKGROUND AND PURPOSE

To determine the influence of diabetes mellitus on stages and long-term outcomes among patients with nasopharyngeal cancer.

MATERIAL AND METHODS

The study summarized 37 patients who were diagnosed as having diabetes mellitus and nasopharyngeal cancer and treated by radiotherapy between January 1999 and December 1999. With a median follow-up of 34.6 mo, we analyzed differences in RFS, MFS, DFS, and OS between the diabetes and the non-diabetes group.

RESULTS

37 patients were involved in our study. According to the Chinese Fuzhou staging system for NPC, which was modified in 1992, 2 patients belong to stage I, 9 stage II, 17 stage III, and 6 stage IV. The 4-yr RFS of diabetes group and non-diabetes group was 52.1% vs 68.2%, the 4-yr MFS was 73.0% vs 72.0%, the 4-yr DFS was 35.1% vs 65.1%, and the OS was 67.6% vs 75.7%. The Wilcoxon (Gehan) test showed there was no significant difference between the two groups of RFS, MFS, and OS, while the diabetes group had a worse DFS than non-diabetes group (Wilcoxon p = 0.0047).

CONCLUSIONS

Patients with diabetes had a worse DFS than non-diabetes, but statistic tests did not show significant differences in RFS, MFS, and OS; further studies should be continue to find out the results in the future.

Effects of the antifungal agent itraconazole on proliferative changes of the forestomach mucosa in alloxan-induced diabetic rats

Alloxan-induced diabetic rats frequently exhibit proliferative lesions of squamous hyperplasia accompanied by chronic inflammation and Candida albicans infection in the forestomach, and some lesions progress to squamous cell carcinoma (SCC). Candida infection causes not only hyperplastic changes with inflammation but might also lead to SCC in human oral mucosa. Thus, the present study was conducted to examine the effects of the antifungal agent itraconazole (ITCZ) on proliferative and inflammatory changes of the forestomach in alloxan-induced diabetic WBN/Kob rats. Diabetes was induced by alloxan at fifteen weeks of age. Rats were allocated to three groups at forty-five weeks of age and were given ITCZ by gavage 0 (vehicle control), 5, and 10 mg/kg/day for four weeks, and they were sacrificed at the sixty-fifth week of age. Mucosal hyperplastic changes were consistently accompanied by inflammation and Candida infections in the 0 mg/kg group. These lesions were reduced by ITCZ (0 mg/kg; 100%, 5 mg/kg; 53.5%, 10 mg/kg; 61.5%). Squamous cell carcinoma was detected in three rats from the 0 mg/kg, but only one rat from the 10 mg/kg dose groups in this study. Itraconazole reduced the degree of mucosal hyperplasia, inflammatory changes, and Candida infection. Therefore, C. albicans infection was an important factor in pathogenesis of mucosal proliferation and inflammation.

[Role of hormonal risk factors in oral cancer development]

Male: female ratio of oral cancer cases (OC) is fairly high. Lower rate of female cases as compared with males suggests that some endocrine factors may play role in the development of tumors. The aim of the present study was to clarify the differences of risk factors for OC among male and female cases. In the Oral and Maxillofacial Department of Semmelweis University 2660 OC (2130 males and 530 females) patients were included into the study. Ratio of smoking, alcohol consumption, elevated serum glucose level and menopausal data of the female patients were registered. Concordant to the literary data, smoking and excessive alcohol consumption proved to be an important risk factor for OC both among male and female patients. However, moderate alcohol consumption was a weak risk factor among male and no risk factor among female cases. Elevated serum glucose level was not significant OC risk among male cases, but was a high risk factor among female patients, especially in gingival cancer cases. The female OC cases were near exclusively postmenopausal, and the term between the time of menopause and clinical OC diagnosis was fairly long (average: 17 year). These results suggest that estrogen-deficiency may play an important role in the initiation of OC. In the female OC cases menopause appeared in significantly younger age, and the rate of hysterectomy was also significantly higher as compared with the tumor-free control cases. These data also support the estrogen-deficiency theory of cancer initiation. In postmenopausal female patients both estrogen-deficiency and elevated fasting glucose proved to be risk factors for OC. These results reveal new aspects concerning the etiology of OC and give a possible explanation how smoking-associated tumors may develop even without smoking.

CHOP 5'UTR-c.279T>C and +nt30C>T variants are not associated with overweight condition or with tumors/cancer in Italians - a case-control study

Background

Type 2 diabetes (T2D) is associated with obesity and has been shown recently to be associated with tumors/cancer. HNF1-beta and JAZF1 genes are associated with T2D and prostate cancer. We have previously shown that CHOP 5'UTR-c.279T>C and +nt30C>T haplotype variants contribute to T2D. CHOP deficiency causes obesity in mice, thus CHOP gene variants may contribute to human obesity. Furthermore, CHOP mediates apoptosis and is implicated in cancer pathogenesis. Hence, we aimed at identifying any potential association of CHOP 5'UTR-c.279T>C and +nt30C>T genotypes and corresponding haplotypes with overweight condition/pre-obesity and tumors/cancer in an Italian dataset.

Methods

We recruited from Italy 45 overweight subjects (body mass index (BMI) ≥ 25) and 44 control subjects (BMI < 25) as well as 54 cases with at least one cancer or at least one tumor and 43 control subjects without tumors/cancer from the general population. We excluded allelic departure from Hardy-Weinberg equilibrium in cases and control subjects, separately.

Results

We assessed the power to detect risk odds ratios by association tests in our datasets. We tested the hypothesis of association of CHOP 5'UTR-c.279T>C and +nt30C>T genotypes and haplotypes with tumors/cancer and, separately, with overweight condition. Both associations were not significant.

Conclusion

From our study, we may conclude that CHOP 5'UTR-c.279T>C and +nt30C>T genotypes and corresponding haplotypes are not associated with tumors/cancer and pre-obesity. However, more studies are warranted to establish the role of CHOP variants in tumor/cancer predisposition and in overweight condition.

Prevention of proliferative changes of forestomach mucosa by blood glucose control with insulin in alloxan-induced diabetic rats

Diabetes mellitus is one of the risk factors for carcinogenesis. Recently we reported that alloxan induces squamous cell carcinoma (SCC) with coincidental inflammation, bacteria/fungal infections, and a severe diabetic condition. The present study was conducted to examine the effects of blood glucose control with insulin on the proliferative changes of the forestomach in alloxan-induced diabetic rats. Male 15-week-old WBN/Kob rats were divided into a control group of non-treated rats with naturally occurring diabetes after 40 weeks of age (non-treated group), alloxan-induced diabetic rats (AL group), and alloxan-induced diabetic rats given insulin implant treatment (AL + In group). The animals were sacrificed at 90 weeks of age for histopathologic examination. The blood glucose and urinary glucose level of the AL + In group fluctuated variously from high to normal levels compared with a constantly high level of AL (for 75 weeks) as well as in the non-treated group (for 50 weeks). The mucosal hyperplasia in the forestomach developed in 88.2% of the AL group and 37.5% of the non-treated group, but in only 10.0% of the AL + In group. SCC was only detected in 23.5% of the AL group. Hyperplastic changes were constantly accompanied by inflammation and fungal/bacterial infections in the AL and non-treated groups, whereas inflammation and fungal infection were completely suppressed in the AL + In group. These findings demonstrate that blood glucose control suppressed neoplastic changes in alloxan-induced diabetic rats. We postulate that inflammation together with bacterial/fungal infections under prolonged severe diabetic conditions play a pivotal role in carcinogenesis.

Diabetes enhances cell proliferation but not Bax/Bcl-2-mediated apoptosis during oral oncogenesis

Markers of cell proliferation (Ki-67 antigen) and apoptosis (Bax, Bcl-2) were studied in an experimental model of chemically induced carcinogenesis in normal and diabetic (type I) Sprague-Dawley rats. Thirteen diabetic and 12 normal rats developed cancer after 4-nitroquinoline-N-oxide treatment, while 6 diabetic and 6 normal animals were used as controls. The biopsies were classified pathologically (from oral mucosal dysplasia to moderately differentiated squamous cell carcinoma) and studied immunohistochemically using monoclonal antibodies against Bax, Bcl-2 and Ki-67 proteins. The Bcl-2/Bax ratio was almost stable during the oncogenesis process in the diabetic rats, whereas the normal rats showed an increased Bcl-2/Bax ratio during the stage of moderately differentiated carcinoma. In contrast, Ki-67 expression was higher in diabetic rats than in normal ones in almost all stages of oral oncogenesis, and it reached significantly increased levels in the stages of normal control tissue, dysplasia and moderately differentiated squamous cell carcinoma. These data suggest that diabetes results in increased cell proliferation during oral oncogenesis, but this is accomplished without affecting the Bax/Bcl-2-mediated apoptotic pathways.

Gender-related hormonal risk factors for oral cancer

Oral cancer (OC) is a neoplasm with fairly high male to female ratio in most populations. The conspicuously lower incidence of this tumor among women than man is suggestive of certain endocrine involvement in its development. The aim of the present case-control study was to clarify the origin of this gender-specific risk of OC incidence. 2660 inpatients (530 females and 2130 males) with squamous cell OC at the Department of Oral and Maxillofacial Surgery were included in a case-control study. Smoking, alcohol consumption, elevated fasting serum glucose level and menopausal histories of female cases were registered. Smoking and excessive alcohol intake proved to be strong risk factors for OC both in the male and female group. However, moderate alcohol consumption was a weaker risk factor for male patients, and it presented no risk for female cases. Elevated fasting glucose level was not a demonstrable OC risk factor among males, however, it proved to be strong risk factor for OC among female patients, especially in gingival cancer cases. The almost exclusively postmenopausal state of female OC patients and the long mean interval (17 years) between their menopause and OC diagnosis suggested an important role of estrogen deficiency in OC epidemiology. The significantly younger mean age at menopause and the significantly higher rate of hysterectomy among female OC cases in comparison with their controls also support the estrogen deficiency hypothesis. This novel hypothesis of estrogen deficiency and elevated fasting glucose as risk factors for OC in postmenopausal women may provide new insights into the etiology of oral malignancies.

Enhancement of erbB2 and erbB3 expression during oral oncogenesis in diabetic rats

PURPOSE

The expression of erbB2 and erbB3 receptors was investigated in an experimental model of chemically induced oral carcinogenesis in normal and diabetic (type I) Sprague-Dawley rats.

METHODS

Thirteen diabetic and twelve normal rats developed precancerous and cancerous lesions after 4-nitroquinoline-N-oxide treatment, while six diabetic and six normal animals were used as controls. Sections of biopsies from all animals were classified histologically in the following categories: normal mucosa, hyperplasia, dysplasia, early invasion, well- and moderately-differentiated squamous cell carcinoma. Each section was studied immunohistochemically using monoclonal antibodies against erbB2 and erbB3 proteins and six representative histological regions in each section were analysed.

RESULTS

The erbB2 was expressed at very low levels in normal rats, while in diabetic animals its expression was significantly increased during early invasion (P = 0.04). The erbB3 expression was significantly elevated in well-differentiated carcinoma in normal animals (P = 0.01), while in diabetic animals it was significantly increased during oral mucosal hyperplasia and dysplasia (P = 0.03 and 0.0007, respectively). The comparison of erbB2 expression between diabetic and normal rats revealed significant differences in all stages except for the tumor stage of moderately differentiated carcinoma (P = 0.01, 0.00001, 0.00001, 0.003, and 0.00001). In regard to erbB3 expression, significant differences between diabetic and normal rats existed only in normal, non-cancerous and precancerous stages (P = 0.007, 0.0001, 0.0003).

CONCLUSIONS

It seems that diabetes enhances the expression of both erbB2 and erbB3 in certain stages of oral oncogenesis possibly resulting in promotion of cell proliferation and inhibition of apoptosis.