Oral cancer in 57,518 industrial workers of Gujarat, India: a prevalence and followup study.
In Gujarat, India, 57,518 industrial workers over 35 years old were examined for oral lesions. At a two-year interval, 43,654 workers were re-examined. Biopsies were taken from 13,223 lesions. In the initial examination, 29 oral cancers were diagnosed, representing a prevalence rate of 50/100,000. After two years, 22 new oral cancers were diagnosed, representing an incidence rate of 25/100,000 per year. Over 90% were squamous carcinomas, with the majority of lesions occurring in the oropharynx and tongue. All patients who developed squamous carcinomas had tobacco habits, while 85% of the entire study population had oral habits in some form. Their most common habits were smoking tobacco alone or in combination with chewing "pan"/"supari." Of the carcinomas that developed during  a two-year interval, 62% appeared in previously normal appearing mucosa. Leukoplakia was the only oral lesion that proved to be precancerous, with a transformation rate of 0.13% in a two-year interval.
D000328:Adult; D002277:Carcinoma / Q000453:epidemiology; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007194:India; D007972:Leukoplakia, Oral / Q000453:epidemiology; D008228:Lymphoma, Non-Hodgkin / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000453:epidemiology*; D009787:Occupational Medicine; D010610:Pharyngeal Neoplasms / Q000453:epidemiology; D010947:Plants, Toxic; D011230:Precancerous Conditions / Q000453:epidemiology; D012907:Smoking; D014030:Tobacco, Smokeless; D014062:Tongue Neoplasms / Q000453:epidemiology