Diagnostic aids for detection of oral precancerous conditions

PTEN gene polymorphisms and susceptibility to oral squamous cell carcinoma in a Chinese Han population

The tumor suppressor gene phosphatase and tensin homologue (PTEN) plays a significant role in regulating cell growth, proliferation, and apoptosis. However, there are no data regarding the role of PTEN polymorphisms in the development of oral squamous cell carcinoma (OSCC). A hospital-based case-control study was conducted to investigate the potential association between PTEN polymorphisms and the risk of OSCC in a Chinese Han population. The study population comprised 201 patients with OSCC and 199 healthy controls. Seventeen single-nucleotide polymorphisms (SNPs) of PTEN were investigated and genotyped using Sequenom Mass ARRAY and iPLEX-MALDI-TOF technology. The observed genotype frequencies of these polymorphisms were in agreement with Hardy-Weinberg equilibrium in the control group (P > 0.05 for all). The heterozygous CT genotype was not associated with significantly increased risk for OSCC (OR = 0.89, 95 % CI = (0.55-1.42), P = 0.83), the TT genotype was not associated with increased risk for OSCC (OR = 1.01, 95 % CI = (0.58-1.74), P = 0.74) compared to the PTEN SNP rs1234224 homozygous CC genotype. Meanwhile, CT/TT variants were not associated with increased risk for OSCC compared with the CC genotype (OR = 0.93, 95 % CI = 0.60-1.44, P = 0.73). The T allele was not associated with significantly increased risk compared to the C allele (OR = 0.99, 95 % CI = 0.72-1.58, P = 0.69). Similar associations with the risk of OSCC were observed for the other genotypes of PTEN gene polymorphisms. There were no significant differences in the distribution of the genotype and allele frequencies of polymorphisms of the PTEN gene between the OSCC patients and controls in a Chinese Han population. Further studies are needed to clarify the specific roles of PTEN polymorphisms in the etiology of OSCC.

Role of micronucleus in oral exfoliative cytology

In the last few years, the interest for oral cytology as a diagnostic and prognostic methodology, for monitoring patients in oral potentially malignant disorders and oral cancer has re-emerged substantially. In 1983, buccal mucosal micronuclei assay was first proposed to evaluate genetic instability. There are biomarkers that predict if a potentially malignant disorder is likely to develop into an aggressive tumor. These genotoxic and carcinogenic chemicals have been reported to be potent clastogenic and mutagenic agents which are thought to be responsible for the induction of chromatid/chromosomal aberrations resulting in the production of micronuclei. Various studies have concluded that the gradual increase in micronucleus (MN) counts from normal oral mucosa to potentially malignant disorders to oral carcinoma suggested a link of this biomarker with neoplastic progression. MN scoring can be used as a biomarker to identify different preneoplastic conditions much earlier than the manifestations of clinical features and might specifically be exploited in the screening of high-risk population for a specific cancer. Hence, it can be used as a screening prognostic and educational tool in community centers of oral cancer.

Recommendations for screening and early detection of common cancers in India

Cancers of the breast, uterine cervix, and lip or oral cavity are three of the most common malignancies in India. Together, they account for about 34% of more than 1 million individuals diagnosed with cancer in India each year. At each of these cancer sites, tumours are detectable at early stages when they are most likely to be cured with standard treatment protocols. Recognising the key role that effective early detection and screening programmes could have in reducing the cancer burden, the Indian Institute for Cytology and Preventive Oncology, in collaboration with the US National Cancer Institute Center for Global Health, held a workshop to summarise feasible options and relevant evidence for screening and early detection of common cancers in India. The evidence-based recommendations provided in this Review are intended to act as a guide for policy makers, clinicians, and public health practitioners who are developing and implementing strategies in cancer control for the three most common cancers in India.

Peroxiredoxin 1 suppresses apoptosis via regulation of the apoptosis signal-regulating kinase 1 signaling pathway in human oral leukoplakia

Peroxiredoxin 1 (Prx1) has a significant role in several malignant types of tumor. However, the role of Prx1 in oral leukoplakia (OLK) has remained to be elucidated. OLK is a common precancerous lesion of the oral mucosa that has a very high malignant transformation rate. The aim of the present study was to investigate the roles of Prx1, and its association with apoptosis signal-regulating kinase 1 (ASK1) and p38 in OLK. A total of 20 OLK samples and 10 normal oral mucosa samples were obtained from patients at the Beijing Stomatological Hospital (Beijing, China). The messenger RNA (mRNA) and protein expression levels of Prx1, ASK1 and p38 were determined by polymerase chain reaction and western blot analysis, respectively. Flow cytometry was used to detect cell apoptosis. The interaction between Prx1 and ASK1 was examined in H₂O₂-treated DOK cells by glutathione-S-transferase pull-down assays and by co-immunoprecipitation in vitro. Compared with those of the normal oral mucosa, the mRNA levels of Prx1, ASK1 and p38 were elevated in OLK tissues (P<0.05). The protein expression levels of Prx1, phosphorylated-ASK1 (p-ASK1) and p-p38 were also significantly enhanced in OLK tissues compared with those of the normal mucosa (P<0.05). In Prx1-knockdown DOK cells, ASK1 and p38 were activated, leading to enhanced levels of apoptosis in response to H₂O₂. No clear interaction between Prx1 and ASK1 was detected in H₂O₂-treated DOK cells. Prx1 was suggested to be involved in OLK pathogenesis by providing resistance against extracellular damages from oxidative stress via inhibition of the ASK1-induced apoptotic signaling pathway. Targeting Prx1 may provide a novel therapeutic strategy for the treatment of patients with OLK.

Tacrolimus 0.03% ointment in labial discoid lupus erythematosus: A randomized, controlled clinical trial

In this randomized, controlled clinical trial to compare efficacy and safety, 41 patients with labial discoid lupus erythematosus (DLE) were randomized to 2 groups, either receiving tacrolimus 0.03% ointment (n = 22) or triamcinolone acetonide 0.1% cream (n = 19). Each patient was treated with 3, 2, and 1 daily doses in the first, second, and third weeks, respectively, for 1 course. After the 3 week treatment, patients with complete disappearance of erosion were followed up for 3 months. After the 3 week application, 20 participants in the tacrolimus group and 19 in the triamcinolone acetonide group completed the study. The rates of complete response were 70% and 89.5% in tacrolimus-treated and triamcinolone acetonide-treated patients, respectively, with no significant difference (P = .235). Reduction in erosion and erythema showed no significant difference between groups (P > .05). Final reduction in reticulation areas and numeric rating scale scores were significantly greater in the tacrolimus group than in the triamcinolone acetonide group (P = .013; P = .048, respectively). Only 1 patient receiving tacrolimus presented with slight discomfort. There was no significant difference in 3 month recurrence rate between the groups (P > .05). Topical tacrolimus is considered as effective as triamcinolone acetonide for the management of labial DLE.

Oral Cavity Cancer: Risk Factors, Pathology, and Management

Oral cavity cancers are predominantly squamous cell carcinomas, which arise from premalignant lesions through a multistep carcinogenesis process. Tobacco and alcohol are the major etiologic factors, although human papillomavirus has also recently been implicated as a causative agent. The possibility of a second primary malignancy should be considered during the diagnostic evaluation of head and neck cancers, as well as during the posttreatment surveillance phase. The goals of treatment are not only to improve survival outcomes but also to preserve organ function. These cancers are generally treated with a combination of surgery, radiation therapy, and chemotherapy. A multidisciplinary approach, involving surgeons, medical oncologists, and radiation oncologists, as well as dentists, dietitians, and rehabilitation therapists, is generally required for optimal treatment planning and management of patients with head and neck cancer.

Upregulation of vascular endothelial growth factor mRNA level is significantly related to progression and prognosis of oral squamous cell carcinomas

BACKGROUND/PURPOSE

Vascular endothelial growth factor (VEGF) is a potent angiogenic factor. This study evaluated whether the VEGF mRNA level in oral squamous cell carcinoma (OSCC) tissue could be a biomarker to predict the progression and prognosis of OSCCs in Taiwan.

METHODS

This study used quantitative real-time reverse transcription-polymerase chain reaction (quantitative RT-PCR) to detect the VEGF mRNA levels in 60 OSCC specimens. Threshold cycle (CT) was defined as the PCR cycle number needed to generate a predetermined amount of DNA (threshold). The relative amount of tissue VEGF mRNA, standardized against the amount of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) mRNA, was expressed as ΔCT = (VEGF CT - GAPDH CT). For a chosen threshold, a smaller starting copy number of mRNA results in a higher CT value. Thus, the lower the ΔCT, the greater the copy number of VEGF mRNA in tissues.

RESULTS

The lower mean VEGF mRNA ΔCT value was significantly associated with OSCCs with larger tumor size (p = 0.040), positive lymph node metastasis (p = 0.023), and more advanced clinical stages (p = 0.008). VEGF mRNA ΔCT value < 4.2 (p = 0.026) was identified as an independent unfavorable prognosis factor using multivariate regression analyses. Moreover, Kaplan-Meier curve showed that OSCC patients with a VEGF mRNA ΔCT value < 4.2 had a significantly poorer overall survival than those with a VEGF mRNA ΔCT value ≥4.2 (log-rank test, p = 0.0427).

CONCLUSION

The OSCC tissue VEGF mRNA level can be used to predict the progression and prognosis of OSCCs in Taiwan.

Quantitative risk stratification of oral leukoplakia with exfoliative cytology

Exfoliative cytology has been widely used for early diagnosis of oral squamous cell carcinoma (OSCC). Test outcome is reported as “negative”, “atypical” (defined as abnormal epithelial changes of uncertain diagnostic significance), and “positive” (defined as definitive cellular evidence of epithelial dysplasia or carcinoma). The major challenge is how to properly manage the “atypical” patients in order to diagnose OSCC early and prevent OSCC. In this study, we collected exfoliative cytology data, histopathology data, and clinical data of normal subjects (n=102), oral leukoplakia (OLK) patients (n=82), and OSCC patients (n=93), and developed a data analysis procedure for quantitative risk stratification of OLK patients. This procedure involving a step called expert-guided data transformation and reconstruction (EdTAR) which allows automatic data processing and reconstruction and reveals informative signals for subsequent risk stratification. Modern machine learning techniques were utilized to build statistical prediction models on the reconstructed data. Among the several models tested using resampling methods for parameter pruning and performance evaluation, Support Vector Machine (SVM) was found to be optimal with a high sensitivity (median>0.98) and specificity (median>0.99). With the SVM model, we constructed an oral cancer risk index (OCRI) which may potentially guide clinical follow-up of OLK patients. One OLK patient with an initial OCRI of 0.88 developed OSCC after 40 months of follow-up. In conclusion, we have developed a statistical method for qualitative risk stratification of OLK patients. This method may potentially improve cost-effectiveness of clinical follow-up of OLK patients, and help design clinical chemoprevention trial for high-risk populations.

Techniques for early diagnosis of oral squamous cell carcinoma: Systematic review

Background and objectives

The diagnosis of early oral potentially malignant disorders (OPMD) and oral squamous cell carcinoma (OSCC) is of paramount clinical importance given the mortality rate of late stage disease. The aim of this study is to review the literature to assess the current situation and progress in this area.

Material and Methods

A search in Cochrane and PubMed (January 2006 to December 2013) has been used with the key words “squamous cell carcinoma”, “early diagnosis” “oral cavity”, “Potentially Malignant Disorders” y “premalignant lesions”. The inclusion criteria were the use of techniques for early diagnosis of OSCC and OPMD, 7 years aged articles and publications written in English, French or Spanish. The exclusion criteria were case reports and studies in other languages.

Results

Out of the 89 studies obtained initially from the search 60 articles were selected to be included in the systematic review: 1 metaanalysis, 17 systematic reviews, 35 prospective studies, 5 retrospective studies, 1 consensus and 1 semi-structured interviews.

Conclusions

The best diagnostic technique is that which we have sufficient experience and training. Definitely tissue biopsy and histopathological examination should remain the gold standard for oral cancer diagnose. In this systematic review it has not been found sufficient scientific evidence on the majority of proposed techniques for early diagnosis of OSCC, therefore more extensive and exhaustive studies are needed.

Key words: Squamous cell carcinoma, early diagnosis, oral cavity, potentially malignant disorders, premalignant lesions.

Estimation of Tissue Optical Parameters with Hyperspectral Imaging and Spectral Unmixing

Early detection of oral cancer and its curable precursors can improve patient survival and quality of life. Hyperspectral imaging (HSI) holds the potential for noninvasive early detection of oral cancer. The quantification of tissue chromophores by spectral unmixing of hyperspectral images could provide insights for evaluating cancer progression. In this study, non-negative matrix factorization has been applied for decomposing hyperspectral images into physiologically meaningful chromophore concentration maps. The approach has been validated by computer-simulated hyperspectral images and in vivo tumor hyperspectral images from a head and neck cancer animal model.

[Feasability study of screening for malignant lesions in the oral cavity targeting tobacco users]

INTRODUCTION

Oral cavity cancer is frequent. Prognosis of this cancer is closely linked to the development. Although the oral cavity is a potentially accessible site for examination, up to 50% of oral cancers are not detected until the disease is well advanced.

PATIENTS AND METHOD

In a region where incidence rate is particularly high, local teams involved in screening, in epidemiological survey, in diagnosis and treatment of oral cancer performed a pilot feasibility study to improve strategy of early detection of oral cancer and premalignant lesion. Tobacco venders were solicited to distribute a flyer, which invite smokers to a free examination by general practitioner. General practitioners were invited to examine smokers, and to fill a predeterminate systematic oral cavity examination record during 3 months. They were asked to refer to a specialist if there was a potentially malignant disorder.

RESULTS

The involvement of tobacco venders was rated as 67.3%. Ninety-three patients were included in 3 months. General practitioners referred 27% of the examinated patients. Among them, only 63.6% really saw a specialist, and a premalignant lesion was confirmed in 15.3%; further exams were carried out in 28.6%; a benign lesion was diagnosed in 57.1%.

DISCUSSION/CONCLUSION

Original incentives for oral cavity screening were performed, based on multidisciplinary network. Nevertheless, it remains hardship to reach the targeted population and to maintain the patients in health system.

Oral cancer incidence and mortality in China, 2011

OBJECTIVE

To descript the incidence and mortality rates of oral cancer among Chinese population in 2011, and provide valuable data for oral cancer prevention and research.

METHODS

Data from 177 population-based cancer registries distributed in 28 provinces were accepted for this study after evaluation based on quality control criteria, covering a total of 175,310,169 populations and accounting for 13.01% of the overall national population in 2011. Incidence and mortality rates were calculated by area, gender and age groups. The numbers of new cases and deaths were estimated using the 5-year age-specific cancer incidence/mortality rates and the corresponding populations. The Chinese population in 2000 and World Segi's population were used for age-standardized rates.

RESULTS

The estimate of new cases diagnosed with oral cancer was 39,450 including 26,160 males and 13,290 females. The overall crude incidence rate for oral cancer was 2.93/100,000. The age-standardized rates by China (ASRCN) population and by World population (ASRwld) were 2.22/100,000 and 2.17/100,000, respectively. Among subjects aged 0-74 years, the cumulative incidence rate was 0.25%. The estimated number of oral cancer deaths of China in 2011 was 16,933, including 11,794 males and 5,139 females. The overall crude mortality rate was 1.26/100,000, accounting for 0.80% of all cancer deaths. The ASRCN and ASRwld for mortality were 0.90/100,000 and 0.89/100,000, respectively. Among subjects aged 0-74 years, the cumulative mortality rate was 0.10%. The incidence and mortality rates of oral cancer were much higher in males and urban areas than in females and rural areas. In addition, the incidence and mortality rates were increased by the raising of ages.

CONCLUSIONS

Results in the study may have important roles for oral cancer prevention and research. Although oral cancer burden of China is not high, we must pay attention to this malignancy as well. In addition, further researches need to be done for primary and secondary prevention research of oral cancer, especially for the high risk population.

Late stage diagnosis of oral cancer: components and possible solutions

Stage of disease at the diagnosis of oral cancer is thought to be a significant factor in prognosis and outcome (International Agency for Research on Cancer/World Health Organization, 2014). Unfortunately, we continue to diagnose almost 2/3 of these cancers at advanced stages of disease despite the ongoing research for devices/methods to aid the clinicians in detection and accurate oral mucosal lesion diagnosis. This paper explores both the nature of oral cancer and the adjuncts available for detection, and presents the current issues in diagnostic delays of oral cancer detection.

The clinical effectiveness of reflectance optical spectroscopy for the in vivo diagnosis of oral lesions

Optical spectroscopy devices are being developed and tested for the screening and diagnosis of oral precancer and cancer lesions. This study reports a device that uses white light for detection of suspicious lesions and green–amber light at 545 nm that detect tissue vascularity on patients with several suspicious oral lesions. The clinical grading of vascularity was compared to the histological grading of the biopsied lesions using specific biomarkers. Such a device, in the hands of dentists and other health professionals, could greatly increase the number of oral cancerous lesions detected in early phase. The purpose of this study is to correlate the clinical grading of tissue vascularity in several oral suspicious lesions using the Identafi^® system with the histological grading of the biopsied lesions using specific vascular markers. Twenty-one patients with various oral lesions were enrolled in the study. The lesions were visualized using Identafi^® device with white light illumination, followed by visualization of tissue autofluorescence and tissue reflectance. Tissue biopsied was obtained from the all lesions and both histopathological and immunohistochemical studies using a vascular endothelial biomarker (CD34) were performed on these tissue samples. The clinical vascular grading using the green–amber light at 545 nm and the expression pattern and intensity of staining for CD34 in the different biopsies varied depending on lesions, grading ranged from 1 to 3. The increase in vascularity was observed in abnormal tissues when compared to normal mucosa, but this increase was not limited to carcinoma only as hyperkeratosis and other oral diseases, such as lichen planus, also showed increase in vascularity. Optical spectroscopy is a promising technology for the detection of oral mucosal abnormalities; however, further investigations with a larger population group is required to evaluate the usefulness of these devices in differentiating benign lesions from potentially malignant lesions.

Genetic variants in AKT1 gene were associated with risk and survival of OSCC in Chinese Han Population

BACKGROUND

AKT1 is an important downstream effector of PTEN/PI3K/AKT signal transduction pathway. Aberrant expression and genetic variant of AKT1 gene are suggested to be involved in several types of human cancers, including OSCC. The aim of this study was to investigate the possible association between AKT1 gene polymorphisms and OSCC in Chinese Han Population.

METHODS

A total of 182 OSCC patients and 207 cancer-free controls were enrolled for this hospital-based study. Five single-nucleotide polymorphisms (SNPs) on AKT1 (rs1130214, rs1130233, rs2494732, rs3730358, rs3803300) were investigated and genotyped by Sequenom Mass ARRAY & iPLEX-MALDI-TOF technology. Chi-square test, SHEsis software, and Kaplan-Meier method were used to evaluate the relationship between selected SNPs and OSCC susceptibility and progression.

RESULTS

Significant difference of genotype distribution was observed between cases and control group at SNP sites rs1130214 (P = 0.006) and rs3803300 (P = 0.033, P = 0.003 for heterozygote and homozygous mutant, respectively). In the haplotype analysis, haplotype H4 which contained mutant-type allele of rs1130214 and rs3803300 was also related to OSCC risk (OR = 1.974, 95% CI = 1.048-3.718). Moreover, CT genotype of rs3730358 was associated with higher risk of OSCC progression (HR = 2.466, 95% CI = 1.017-5.981).

CONCLUSION

Our results indicated that rs1130214 and rs3803300 were related to OSCC susceptibility in Chinese Han Population. In addition, rs3730358 might be associated with progression-free survival time of OSCC patients, suggesting that this SNP could be a potential prognosis marker for OSCC.

Human beta-defensin-1 suppresses tumor migration and invasion and is an independent predictor for survival of oral squamous cell carcinoma patients

Background

Human beta-defensin-1 (hBD-1) has recently been considered as a candidate tumor suppressor in renal and prostate cancer. The aim of this study was to investigate the role of hBD-1 in the progression of oral squamous cell carcinoma (OSCC) and its potential as diagnostic/prognostic biomarker and therapeutic target for OSCC.

Methods

HBD-1 expression in tissues at different stages of oral carcinogenesis, as well as OSCC cell lines was examined. HBD-1 was overexpressed in HSC-3, UM1, SCC-9 and SCC-25 cells and subjected to cell growth, apoptosis, migration and invasion assays. Tissue microarray constructed with tissues from 175 patients was used to examine clinicopathological significance of hBD-1 expression in OSCC.

Results

HBD-1 expression decreased from oral precancerous lesions to OSCC and was lower in OSCC with lymph node metastasis than those without metastasis. In vitro, the expression of hBD-1 was related to the invasive potential of OSCC cell lines. Induction of exogenous expression of hBD-1 inhibited migration and invasion of OSCC cells, probably by regulation of RhoA, RhoC and MMP-2; but had no significant effect on proliferation or apoptosis. In a cohort of patients with primary OSCC, cases with no expression of hBD-1 had more chance to be involved in lymph node metastasis. Eventually, the positive expression of hBD-1 was associated with longer survival of patients with OSCC, and multivariate analysis and ROC curve analysis confirmed hBD-1 positivity to be an independent prognostic factor of OSCC, especially OSCC at early stage.

Conclusions

Overall, these data indicated that hBD-1 suppressed tumor migration and invasion of OSCC and was likely to be a prognostic biomarker and a potential target for treatment of OSCC.