Oral Precancerous Conditions Research Articles

Primary prevention of mouth carcinoma and oral precancerous conditions

Epidemiologic data for the prevalence of oral cancer show marked geographic differences. The incidence of oral cancer in younger individuals seems to be on the increase. Prevalence of oral leukoplakia in German men is 2.3%, in women 0.9%. Risk factors for oral cancer and most variants of oral leukoplakia are identical. Etiologically, tobacco and alcohol are the most important factors. Tobacco in smoked, chewed or snuffed varieties has toxic, tumorigenic and carcinogenic properties. Consumption of tobacco has markedly increased during the last 15 years in some geographic areas. In Germany tobacco consumption has increased 7.5% during the last 4 years. Alcohol affects the permeability of oral mucosa. Oral cancer as well as most forms of oral leukoplakia are avoidable diseases. Strategies for prevention encompass primary, secondary and tertiary prevention. Primary prevention focuses on principal avoidance of tobacco. Anti-tobacco counselling and therapy is actively practiced in dental practices in some countries. Intervention includes the 4 A's as principles (ask, advise, assist, arrange) and is based on nicotine replacement therapy. General dental practice and hospital dentistry should introduce the principles of primary prevention of tobacco consumption. A questionnaire which was sent to EU countries indicated that dental teams are willing to introduce tobacco and alcohol counselling and relevant prevention strategies.

口腔前癌病変，前癌状態の悪性化能に関する組織学的検討

The relationship between epithelial dysplasia and malignancy potential of oral precancerous lesions and precancerous conditions (PL & PC) was histologically examined. Histological epithelial dysplasia was investigated in 41 cases of leukoplakia and erythroplakia (L & E) 39 of lichen planus (LP), 34 of dysplastic epithelium adjacent to squamous cell carcinomas (SCC), and 8 of PL & PC which subsequently became SCC. Dysplastic score was assigned based on the dysplastic criteria of the WHO (1978). The average dysplastic scores were 2.9 ± 2.7 points in L & E, 2.2 ± 1.2 in LP 5.6 ± 2.3 in PL & PC which subsequently become SCC, and 6.3 ± 2.7 in dysplastic epithelium adjacent to SCC. Thus, the degree of dysplasia was obviously associated with the potentiality for malignant transformation. Important dysplastic characteristics were an increased nucleo-cytoplasmic ratio, dropshaped rete processes, cell crowding, pleomorphic cells and nuclei, and hyperchromatic nuclei. The methods used in this study were useful in evaluating the malignancy potential of oral lesions, and provided diagnostic suggestions.

Variations in centromeric heterochromatin among patients with pre‐malignant and malignant oral diseases

Polymorphism of heterochromatic regions of chromosomes 1, 9 and 16 was studied in 60 oral cancer patients, in 40 patients with oral submucous fibrosis (OSMF) and in 60 normal healthy subjects. The size heteromorphism was significantly greater (p less than 0.001) in chromosome I of the patients. Localization variants were also significantly more frequent among the patients (p less than 0.05 for OSMF and less than 0.001 for oral cancer patients). The C-band heteromorphism patterns remained comparable in OSMF and in oral cancer patients, with chromosome I being the most frequently involved. On correlating the tobacco/areca-nut chewing habit with the presence of C-band heteromorphism, we observed that C-band heteromorphism was present in 89% of the habit-free oral cancer patients and 80% of the OSMF patients with relatively shorter exposure to this habit, i.e. less than 5 years. This signifies that genetic factors are important in the causation of oral precancerous and cancerous conditions and that polymorphism of the heterochromatic regions does appear to play a role in these conditions.

Usefulness of serum glycoconjugates in precancerous and cancerous diseases of the oral cavity

Sera from 47 healthy controls, 18 normal individuals with the habit of tobacco chewing, 43 patients with oral precancerous (PC) conditions, and 40 patients with oral cancer (OC) were studied for the levels of total sialic acid (TSA), lipid-bound sialic acid (LSA), mucoid proteins, and protein-bound hexoses (PBH) (galactose and mannose). The changes in the glycoconjugate levels were insignificant between the controls and the normal tobacco chewers. All four parameters were significantly elevated in oral PC patients compared with controls. The levels of PBH and LSA showed significant increase in the oral PC patients compared with the normal tobacco chewers. A significant increase was observed in the levels of TSA, LSA, mucoid proteins, and PBH in OC patients compared with controls, normal tobacco chewers, and patients with oral PC. Increasing levels of all the biomarkers were found with progression of the malignant disease. Elevations in the levels of TSA and LSA were statistically significant in Stage IV patients compared with Stage III patients. The patients with metastases had higher levels of the biomarkers than the patients with primary OC. However, elevations only in LSA levels were statistically significant. These results suggest that evaluations of the serum glycoconjugate levels may be useful in diagnosis of the patients with oral PC or OC. In addition to their value in early detection, they can also help in staging of the disease.

A report on clinical importance of serum glycoconjugates in oral cancer

For evolving a potential Biochemical index for early diagnosis of oral cancer, serum levels of total sialic acid (TSA), lipid bound sialic acid (LSA), mucoid proteins and hexoses (galactose and mannose) were determined in 30 patients with oral cancer. The results were compared with similar values obtained for 30 patients with oral precancerous conditions, 24 healthy controls and 15 normal individuals with a habit of tobacco chewing. All the biomarkers were significantly elevated in oral cancer patients compared to the controls, the normal chewers and precancer patients. The levels of glycoconjugates showed significant increase in patients with oral precancerous conditions compared to the controls. Only LSA and hexoses showed significantly elevated levels in oral precancer patients compared to the normal chewers. The levels of glycoconjugates were more or less comparable between normal chewers and the controls. The parameters evaluated in the oral cancer patients also showed a progressive rise with the clinical stage of the malignant disease. The levels of the four glycoconjugates were also higher in patients with metastasis compared to those with only primary disease. The present findings suggest that the glycoconjugates have clinical utility in diagnosis of the patients with cancer of the oral cavity as well as in staging the disease.

Oral precancerous conditions in peninsular Malaysia

Oral precancerous conditions in peninsular Malaysia

Simultanes Vorkommen von Pr�kanzerosen und Karzinomen in Mund, Rachen und Kehlkopf. Vorl�ufige Ergebnisse einer interdisziplin�ren Studie

The incidence of two simultaneous carcinomas within the organism is 5%, in the region of the upper airways and alimentary tract, less than 1%. With the aid of systematized clinical endoscopic and cyto-histomorphological screening procedures for carcinomas along the “smoker's pathway“, concomitant carcinomas and pre-cancerous states are being detected more and more frequently and at an earlier stage. Between 1976 and 1978, 210 patients presenting with oral leukoplakia of varying genesis and localization, and both benign and malignant, were subjected to systematic dermatological, dental and ENT examinations. A therapy-relevant finding in the ENT region was found in every third patient. In 41 patients with oral pre-cancerous conditions and carcinomas, similar concomitant findings were seen in the larynx in 15%, localized in the glottis in 90% of the cases. — Etiologically particularly high-risk patients proved to be men over 30, with oral leukoplakia and poor oral hygiene and a history of regular smoking and consumption of considerable quantities of alcohol. The basis for the detection of concomitent or consecutive pre-cancerous conditions and early cancers in the region of the upper airways and alimentary tract is the interdisciplinary cooperation covering the inspection of the oral cavityand pharynx and larynx.

An epidemiologic study of oral cancer and precancerous conditions among 101,761 villagers in Maharashtra, India.

AbstractIn an extensive epidemiologic house‐to‐house survey, undertaken to study oral cancer and precancerous conditions, 101,761 villagers were examined in the Poona district in the Maharashtra state in India. Besides detection of 12 oral cancers, prevalences were established for leukoplakia (0.67%), preleukoplakia (0.86%), and submucous fibrosis (0.03%). The sample was also studied for chewing and smoking habits, which were practised by 54.4% of the individuals. Among males the most common habit was chewing tobacco with lime, whereas the dominating habit among females was the use of mishri (burned tobacco). The strongest association found was between bidi smoking and mixed habits and leukoplakia. Only a few cases of leukoplakia were found among mishri users. Except for submucous fibrosis it was found that prevalence does not depend on sex if tobacco habits are taken into account.

Variations in histochemical properties of hydrolytic enzymes in oral precancerous conditions.

Variations in histochemical properties of hydrolytic enzymes in oral precancerous conditions.

Reverse smoking in Andhra Pradesh, India: a study of palatal lesions among 10,169 villagers.

In the district of Srikakulam in Andhra Pradesh in South India the habit of reverse smoking is widespread. In a house to house survey of oral cancer and precancerous conditions, comprising 10,169 villagers, 43·8% were reverse smokers; the female: male ratio being 1·7: 1. Ten previously undiagnosed cases of oral cancer, 9 located to palate, were found. The prevalences for leukoplakia, preleukoplakia and leukokeratosis nicotina palati were 4·9%, 2·9% and 9·5%. Of 497 leukoplakias, 422 were located to the palate and 413 of these patients had the habit of reverse smoking. Histologically, 80% of 381 palatal biopsies had a hyperorthokeratosis. Epithelial atypia was found in 15·3% of leukoplakias, in 3·6% of the preleukoplakias, and in 9·1% of leukokeratosis nicotina palati. Various explanations for the habit of reverse smoking are suggested and discussed. In addition to reverse smoking, other tobacco habits were also recorded; all habits and oral lesions were compared and have been discussed according to their apparent interrelationships and distribution by sex and age.