Role of areca nut in betel quid-associated chemical carcinogenesis: current awareness and future perspectives

Automated classification of cells in sub-epithelial connective tissue of oral sub-mucous fibrosis-An SVM based approach

Aim: To describe a novel neural network based oral precancer (oral submucous fibrosis; OSF) stage detection method.

Method: The wavelet coefficients of transmission electron microscopy images of collagen fibres from normal oral submucosa and OSF tissues were used to choose the feature vector which, in turn, was used to train the artificial neural network.

Results: The trained network was able to classify normal and oral precancer stages (less advanced and advanced) after obtaining the image as an input.

Conclusions: The results obtained from this proposed technique were promising and suggest that with further optimisation this method could be used to detect and stage OSF, and could be adapted for other conditions.

https://jcp.bmj.com/content/jclinpath/58/9/932.full.pdf

A novel wavelet neural network based pathological stage detection technique for an oral precancerous condition

Objective: To test the effect of dietary nutrients on oral precancerous lesions in a reverse-smoking (i.e. smoking with the glowing end inside the mouth) population in South India. Design: Case‐control. Cases with precancerous lesions were matched to an equal number of lesion-free controls matched on age (^5 years), sex and village. All subjects used tobacco in some form. Dietary data were obtained using an intervieweradministered food-frequency questionnaire, designed for use in this population. All interviews were conducted blinded to the disease status of the subject. Data were analysed using logistic regression. Setting: Nineteen rural villages in Srikakulam District, Andhra Pradesh. Subjects: From a survey of 6007 tobacco users, 485 (79% women) were found to have precancerous, mostly palatal, lesions (cases), and 487 lesion-free subjects were selected as controls. Results: All eligible subjects consented to participate and nearly all (.99%) had complete data for analyses. Reverse smoking was the most common form of tobacco use among cases (81.9%) and controls (73.5%), and reverse smokers were 5.19 times more likely than chewers to have these lesions (95% confidence intervala 1.35, 19.9). After controlling for relevant covariates, including the type of tobacco use, protective linear effects were observed for zinc (70% reduction across the interquartile range, P , 0:002), calcium (34% reduction, P , 0:002), fibre (30% reduction, P , 0:009), riboflavin (22% reduction, P , 0:03) and iron (17% reduction, P , 0:05). Conclusions: Several dietary nutrients appear to protect against oral precancerous lesions that are strongly associated with reverse smoking. The results of this study indicate scope for targeting dietary factors in preventing oral cancer, which should be coupled with aggressive anti-tobacco use efforts.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/109CA51AAA4F3C242E1E01C737E5D700/S1368980002000435a.pdf/div-class-title-dietary-exposures-and-oral-precancerous-lesions-in-srikakulam-district-andhra-pradesh-india-div.pdf

Dietary exposures and oral precancerous lesions in Srikakulam District, Andhra Pradesh, India

Areca quid (AQ) chewing has been implicated an independent risk factor for the development of oral cancer. Taiwanese areca quid (AQ) refers to a combination of areca nut (AN), lime, and inflorescence of Piper betle Linn. (IPB) or Piper betle leaf (PBL). Studies of AQ in other countries reported that AN extract combined with lime generates reactive oxygen species (ROS), such as hydroxyl radical (HO.), known to be a contributing factor in oral mucosa damage. To determine whether HO. is formed in the oral cavity during AQ chewing, the formation of meta-tyrosine (m-Tyr) and ortho-tyrosine (o-Tyr) from l-phenylalanine (Phe) was confirmed. It was demonstrated that combined aqueous extracts of AN, lime, metal ions (such as Cu2+ and Fe2+), and IPB or PBL produced HO.. Thus, the yield of HO. significantly increases when higher amounts of IPB or lime are added and also when Cu2+ and Fe2+ are increased. Further, the omission of any one of these ingredients significantly reduces the formation of HO.. Our results found that chewing AQ with IPB generated significantly higher HO. than chewing AQ with PBL, and may result in greater oxidative damage to the surrounding oral mucosa.

Ingredients contribute to variation in production of reactive oxygen species by areca quid.

Oral Submucous Fibrosis (OSF) is a precancerous condition of oral cavity and oropharynx. Its etiopathogenesis is still obscure. Epithelial dysplasia is considered an important indicator of it. In the present study, the authors try to ascertain bioinorganic parameters as alternate indicators of malignant potential of OSF along with other clinicopathological attributes. They also try to identify causative factors. Thirty-six OSF patients, showing different degrees of epithelial dysplasia, and 12 normal individuals are studied with special reference to trace metal contents (Zn and Fe) in oral tissues. Statistical analyses of data indicate that trace metal contents can be regarded as an alternate indicator of the precancerous nature of OSF. Some clinicopathological attributes that are easier and cheaper to measure may also indicate OSF.

D. Roy

Papers

Zinc and iron as bioindicators of precancerous nature of oral submucous fibrosis.