Some studies suggest that periodontal diseases increase the risk of oral cancer, but contradictory results also exist. Inadequate control of confounders, including life course exposures, may have influenced prior findings. We estimate the extent to which high levels of periodontal diseases, measured by gingival inflammation and recession, are associated with oral cancer risk using a comprehensive subset of potential confounders and applying a stringent adjustment approach. In a hospital-based case-control study, incident oral cancer cases (N = 350) were recruited from two major referral hospitals in Kerala, South India, from 2008 to 2012. Controls (N = 371), frequency-matched by age and sex, were recruited from clinics at the same hospitals. Structured interviews collected information on several domains of exposure via a detailed life course questionnaire. Periodontal diseases, as measured by gingival inflammation and gingival recession, were evaluated visually by qualified dentists following a detailed protocol. The relationship between periodontal diseases and oral cancer risk was assessed by unconditional logistic regression using a stringent empirical selection of potential confounders corresponding to a 1% change-in-estimates. Generalized gingival recession was significantly associated with oral cancer risk (Odds Ratio = 1.83, 95% Confidence Interval: 1.10-3.04). No significant association was observed between gingival inflammation and oral cancer. Our findings support the hypothesis that high levels of periodontal diseases increase the risk of oral cancer.

Oral cancer is a major public health issue in India with~77,000 new cases and 52,000 deaths yearly. Paan chewing, tobacco and alcohol use are strong risk factors for this cancer in India. Human papillomaviruses (HPVs) are also related to a subset of head and neck cancers (HNCs). We examined the association between oral HPV and oral cancer in a sample of Indian subjects participating in a hospital-based case-control study. We recruited incident oral cancer cases (N 5 350) and controls frequencymatched by age and sex (N 5 371) from two main referral hospitals in Kerala, South India. Sociodemographic and behavioral data were collected by interviews. Epithelial cells were sampled using Oral CDx V R brushes from the oral cancer site and the normal mucosa. Detection and genotyping of 36 HPV genotypes were done using a polymerase chain reaction protocol. Data collection procedures were performed by qualified dentists via a detailed protocol with strict quality control, including independent HPV testing in India and Canada. HPV DNA was detected in none of the cases or controls. Associations between oral cancer and risk factors usually associated with HPV infection, such as oral sex and number of lifetime sexual partners, were examined by logistic regression and were not associated with oral cancer. Lack of a role for HPV infection in this study may reflect cultural or religious characteristics specific to this region in India that are not conducive to oral HPV transmission. A nationwide representative prevalence study is needed to investigate HPV prevalence variability among Indian regions.Worldwide, nearly 300,000 new cases of oral cancers are diagnosed each year, accounting for 145,000 deaths. Approximately 77,000 new cases and 52,000 oral cancer-related deaths occur yearly in India, representing a quarter of all incident cases in the world. 1 Known risk factors include tobacco smoking and chewing, high alcohol consumption and, in a country such as India, paan chewing. 2 Oral human papillomavirus (HPV) infection has recently been recognized as another important risk factor for head and neck cancer (HNC), mainly for the oropharyngeal cancer subsite. In fact,

ABSTRACT:Objectives: Paan chewing is a recognized risk factor for oral cancer in the Asian population. However, there is currently little evidence about the intergenerational psychosocial transmission of paan chewing in South Indian families. We investigated the association between parental and participant's paan chewing in a South Indian population.Methods: A subset of data was drawn from a hospital-based case-control study on oral cancer, the HeNCe Life study, conducted at Government Dental and Medical Colleges of Kozhikode, South India. Analyses were based on 371 non-cancer control participants having diseases unrelated to known risk factors for oral cancer. Demographics, behavioural habits (e.g., paan chewing, smoking), and indicators of socioeconomic position (SEP) of both participants and their parents were collected with the use of a questionnaire-based interview and a life grid technique. Unconditional logistic regression assessed odds ratios (OR) and 95% confidence intervals (95%CI) for the associations between parental and participant's paan chewing, adjusted for confounders.Results: Over half of the participants were male (55.2%) and the mean age of participants was 59 (SD=12) years. After adjusting for age, religion, parents' SEP, parents' education, smoking and alcohol consumption, and perceived parenting behaviour we observed that maternal and paternal paan chewing were significantly associated with the participant's paan chewing (OR=2.40, 95%CI=1.11-5.21) and (OR=3.05, 95%CI=1.48-6.27), respectively. Conclusions:Intergenerational psychosocial transmission of the habit of paan chewing could occur through shared socio-cultural or environmental factors.