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Between 1996 and 1999 we carried out a case-control study in 3 areas in Southern India (Bangalore, Madras and Trivandrum) including 591 incident cases of cancer of the oral cavity (282 women) and 582 hospital controls (290 women), frequency-matched with cases by age and gender. Odds ratios (ORs) and 95% confidence intervals (CIs) were obtained from unconditional multiple logistic regressions and adjusted for age, gender, center, education, chewing habit and (men only) smoking and drinking habits. Key words: oral cancer; tobacco; paan chewing; alcohol; oral hygieneCancer of the oral cavity and pharynx is the first and third commonest cancer in Indian men and women, respectively. 1 Whereas in most areas at high risk for cancer of the oral cavity other than India (e.g., central and Eastern Europe, South America), the ratios between male and female incidence rates range between 3 and 10, in India the male-to-female ratio is approximately 1 (e.g., Madras) or lower than 0.5 (Bangalore). 2 Such very high incidence rates in Indian women reflect the persistent importance in India of paan chewing, a habit that is equally common in the 2 genders. 3 Paan generally includes calcium hydroxide, areca nut (from the Areca catechu tree) and betel leaf (from the Piper betle vine). Tobacco and/or various spices are commonly added. 4 Paan represents a cheap pharmacologically addicting stimulant, principally used by members of low social classes in South Asia. Fewer efforts have been made in Asia to discourage paan chewing than tobacco smoking, 5 and only recently have links been established between paan and oral cancer that cannot be explained by the presence of tobacco. 3,6 Annual per capita consumption of cigarettes in India was maximal in the 1970s and 1980s and declined by approximately 40% in the early 1990s. 7 Two nation-wide surveys 8,9 showed a somewhat lower prevalence of tobacco use in any form in 1993-1994 (23% in urban and 34% in rural areas in men and 4% and 9%, respectively, in women) than in 1987-1988 (26% and 35% in men and 6% and 11% in women, respectively). It is estimated that 150 million males and 34 million females used tobacco in India in 1996. 8,9 Relatively few case-control studies have recently addressed the impact of paan chewing and smoking on oral cancer in India, 10 -12 and information on women and on risk factors other than smoking or chewing is scanty. 12 The present case-control study was conducted in 3 areas of Southern India in order to evaluate the relative importance of smoking, alcohol drinking and paan chewing, with or without tobacco, on cancer of the oral cavity in men and women and the modifying effect, if any, of various indicators of oral hygiene. Our study is part of an international study on oral cancer coordinated by the International Agency for Research on Cancer and carried out also in Italy,

Sexual behaviours are associated with cancer risk at the head and neck cancer subsites that have previously been associated with HPV infection.

A large proportion of TC cases diagnosed in high-resource countries in the last two decades are likely to be due to diagnostic changes. This proportion has progressively increased over time, and it is likely to grow further in the future. Since there is evidence of harm but no proof of benefit from the intense scrutiny of the thyroid, the dangers of overdiagnosis and overtreatment of TC should be urgently addressed.

To investigate the prevalence of, and risk factors for, cervical infection with human papillomavirus (HPV) in the rural province of Shanxi, People's Republic of China, which has relatively high cervical cancer mortality rates, we interviewed and obtained cervical cell samples from 662 women aged 15 -59 years. A total of 24 different HPV types were identified using a GP5 þ /6 þ -based PCR assay able to detect 44 different HPV types. Human papillomavirus prevalence was 14.8% overall and 9.6% among women without cervical abnormalities (14.2 and 8.9%, respectively, age standardised to the world standard population). Multiple-type infections accounted for 30.6% of all infections. By far the most commonly found type was HPV16 (5.7% of all women and 38.8% of HPV-positive women), followed by HPV 58, 52, 33 and 18. Unlike most previous studies published, HPV prevalence was lower among women younger than 35 years (8.7%) than those older than 35 years (17.8%). High-risk HPV types predominated in all age groups. Although low-risk HPV types were rare in young women, they became more common with increasing age. 92.3% of women with cervical intraepithelial neoplasia grade 3 were infected with high-risk HPV types, but none with low-risk types only. No significant difference in HPV positivity was observed by educational level, sexual habits, reproductive history or use of contraceptive methods in this rural lowincome Chinese population.

In terms of worldwide levels, Cuba has an intermediate incidence of cancer of the oral cavity and oro-pharynx. We studied 200 cases of cancer of the oral cavity and pharynx, of whom 57 women (median age = 64) and 200 hospital controls, frequency matched with cases by age and sex, in relation to smoking and drinking history, intake of 25 foods or food groups, indicators of oral hygiene and sexual activity, and history of sexually transmitted diseases. Odds ratios (OR) and 95% confidence intervals (CI) were obtained from unconditional multiple logistic regressions and adjusted for age, sex, area of residence, education, and smoking and drinking habits. In the multivariate model, high educational level and white-collar occupation, but not white race, were associated with halving of oral cancer risk. Smoking ≥30 cigarettes per day showed an OR of 20.8 (95% CI: 8.9–48.3), similar to smoking ≥4 cigars daily (OR = 20.5). Drinking ≥ 70 alcoholic drinks per week showed an OR of 5.7 (95% CI: 1.8–18.5). Hard liquors were by far the largest source of alcohol. Increased risk was associated with the highest tertile of intake for maize (OR = 1.9), meat (OR = 2.2) and ham and salami (OR = 2.0), whereas high fruit intake was associated with significantly decreased risk (OR = 0.4). Among indicators of dental care, number of missing teeth and poor general oral condition at oral inspection showed ORs of 2.7 and 2.6, respectively. Number of sexual partners, marriages or contacts with prostitutes, practice of oral sex and history of various sexually transmitted diseases, including genital warts, were not associated with oral cancer risk. 82% of oral cancer cases in Cuba were attributable to tobacco smoking, 19% to smoking cigars or pipe only. The fractions attributable to alcohol drinking (7%) and low fruit intake (11%) were more modest. Thus, decreases in cigarette and cigar smoking are at present the key to oral cancer prevention in Cuba. © 2001 Cancer Research Campaign http://www.bjcancer.com