Fali S. Mehta

Epidemiologic and histologic study of oral cancer and leukoplakia among 50,915 villagers in India

The paper presents the results of an epidemiologic house‐to‐house survey of oral cancer and lcukoplakia among 50,915 adult villagers in 4 states of India which were selected according to various types of chewing and smoking habits. Twenty‐six oral cancer cases were found in the survey. The prevalence of leukoplakia ranged from 0.2 to 4.9%. There was a predominance of men. Leukoplakias were already observed in the 15‐ to 24‐year age group, and a considerable number were in the 25‐ to 34‐year age group. Intra‐oral locations of the leukoplakias were found to vary within the 4 states depending upon the chewing and smoking habits prevailing. The leukoplakias were analyzed with regard to intra‐oral locatios and correlation with habits. Special habits like hookli smoking and reverse smoking are associated with leukoplakias on the labial mucosa and on the palate, respectively. The histologic analysis of biopsies from 723 leukoplakias showed variations in the type of hyperkeratosis which may depend upon habits. The prevalence of epithelial atypia ranged from 3.0% to 12.4% in the 4 states. Epithelial atypia was seen in 8.4% of homogeneous leukoplakias but in 59.1% of speckled leukoplakias.

An epidemiologic assessment of cancer risk in oral precancerous lesions in India with special reference to nodular leukoplakia.

A cohort of 12,212 tobacco users was followed up annually to assess malignant potential of oral precancerous lesions in the Ernakulam district in Kerala, India. A total of 19 new oral cancers were diagnosed over a period of 8 years, and 15 (79%) of these arose from some preexisting precancerous lesion or condition. Nodular leukoplakia showed highest rate of malignant transformation (16% per year) as six of 13 nodular leukoplakia underwent malignant transformation over a mean follow‐up period of 2.8 years. The relative risk (3243.2) compared with individuals with tobacco habits but without any precancerous oral lesion was also the highest for nodular leukoplakia. In addition, nodular leukoplakia was associated with submucous fibrosis in two patients, which progressed to oral cancer and was the clinical diagnosis for four lesions that turned out to be malignant on histopathologic examination. Nodular appearance was noted in two other precursor lesions as well. Thus, 14 of 19 oral cancers (74%) were either preceded by nodular leukoplakia and with lesions showing a distinct nodular appearance, or had the clinical appearance of nodular leukoplakia.

A follow-up study of sixty-one oral dysplastic precancerous lesions in Indian villagers☆

In a 7-year follow-up study of 107 cases of oral epithelial dysplastic precancerous lesions in Indian villagers, 6.6 per cent were found to develop into carcinomas. A clinical spontaneous regression occurred in 14.8 per cent. Follow-up biopsies showed histologic regression of dysplasia in six cases.

Tobacco-induced changes in oral leukoplakic epithelium

A study of 112 biopsy specimens from Danish oral leukoplakia patients and 145 biopsy specimens from Indian leukoplakia patients revealed a chevron‐like keratinization of the epithelium in a number of cases. Clinically, this type of keratinization was often characterized by a pumice‐like appearance. The clinical and histologic changes were only observed in tobacco users, and appeared to be associated particularly with use of pipes, snuff, and hooklis.

Oral leukoplakia in relation to tobacco habits: A ten-year follow-up study of Bombay policemen

Abstract This is a report of a second follow-up study of 3,674 Bombay policemen after 10 years. One among 117 patients with leukoplakia was reported to have developed oral cancer in the 10-year period. The 10-year incidence rate for leukoplakia was 2.8 per cent. Among chewers, the leukoplakia regressed, whereas among smokers, the leukoplakia was found to be more persistent. Although tobacco chewing remained the most prevalent form of tobacco habit, cigarette smoking was found to be on the increase.

Development and testing of a quantitative food frequency questionnaire for use in Kerala, India

OBJECTIVE To develop and test a food frequency questionnaire (FFQ) for use in rural areas of Kerala, India. DESIGN Based on food use and market surveys of the study area, a quantitative 81-item interviewer-administered FFQ was developed. A validation study was conducted consisting of 24-h diet recalls (24HR) administered on 8 days randomly selected over an entire year and two administrations of the FFQ, one at the beginning of the 1-year period and the other at the end. FFQ and 24HR-derived nutrient scores were compared using correlation and regression analyses and by examining differences in the nutrient scores. SETTING Rural villages in Ernakulum district, Kerala, South India. SUBJECTS In each of 30 households, the male head of household and female food preparer were enrolled. RESULTS Pearson (parametric) correlation coefficients (r(p)) averaged about 0.50 in comparing nutrient scores derived from the 24HR with those from the first FFQ and about 0.55 in comparing the second FFQ. On average, Spearman correlation coefficients (r(s)) were slightly lower than the r(p) in comparing the scores derived from the first FFQ, but virtually identical for the second FFQ. Regression analyses indicated better agreement in the comparison of the 24HR-derived scores with the first FFQ than the second FFQ. Difference scores, however, tended to be larger in comparing the first FFQ scores with the 24HR. CONCLUSIONS This FFQ produces results broadly comparable to those used in Europe and North America, indicating its suitability for comparing exposures within a study population in reference to health-related endpoints.

Chewing and smoking habits in relation to precancer and oral cancer.

SummaryIn a prospective epidemiologic house-to-house survey of a random sample in the district of Ernakulam in Kerala State, the annual incidence rate of leukoplakia per 1,000 adults was found to be 2.1 for males and 1.5 for females. The rate was highest in the mixed tobacco habits group and lowest (0) in the no habits group. During the same period, oral cancer developed only among the individuals, who had a history of a previously diagnosed oral lesion. Malignant transformation was significantly higher among the speckled leukoplakia cases. The rate of malignant transformation was also highest among leukoplakias associated with tobacco chewing habits. These results suggest that leukoplakias associated with different tobacco habits may have a different natural history.

Incidence and early forms of oral submucous fibrosis

The yearly incidence of submucous fibrosis per 100,000 person-years was found to be 9 for males and 20 for females over a 10-year period in the Ernakulam district of Kerala, South India. In the same area possible early case of submucous fibrosis, under the clinical diagnosis of leukoplakia and lichen planus, showed the typical histologic features of the disease.

Influence of Dietary Factors on Oral Precancerous Lesions in a Population-Based Case-Control Study in Kerala, India

Although tobacco is the primary etiologic factor for oral precancerous lesions in India, evidence from other sources indicates that diet may modify risk. This case–control study was designed to minimize a variety of biases in its attempt to investigate the relation between diet and oral precancerous lesions.

Reverse smoking in Andhra Pradesh, India: variability of clinical and histologic appearances of palatal changes.

In Srikakulam, India, 101 patients with palatal lesions due to reverse smoking were followed for 1 year at monthly intervals to analyze the behavior of the various components of their palatal lesions. Of these patients, 24% stopped the habit completely and 27% changed to the conventional type of smoking. Palatal keratosis was very stable, whereas red areas changed into nonpigmented areas. Epithelial dysplasia was found in 23% of the 101 biopsies, the highest being in the red areas. Mild inflammation was seen in about half of the biopsies.