Prostate cancer is the most commonly diagnosed cancer in Canadian males, and is the third most common cause of cancer related deaths with decreasing mortality in men. Previous studies have suggested that an increased risk of prostate cancer among men may be associated with rural environment. The etiology of prostate cancer is not precisely known among men in rural Saskatchewan. We investigated the prevalence of prostate cancer and the putative relationship between rural exposures (occupational i.e. farming and environmental), personal smoking history, family history of cancer and prostate cancer. A baseline mail out survey was conducted in 2010-2011 of 11,982 households located in four geographic regions (South West, South East, North West, and North East) of Saskatchewan, Canada. Completed questionnaires were obtained from 4,624 households (8,261 individuals). The questionnaires collected information on individual (demographic factors, exposure to pesticides including insecticides, herbicides and fungicides) and contextual (household characteristics such as income, smoking) determinants from a rural population. In total 2,938 males (114 prostate cancer cases) were included for this analysis who were older than 45 years. Logistic regression analysis was used to analyze the relationship between independent variables and prostate cancer. Among prostate cancer cases, 46% of men lived on farms of rural Saskatchewan. The age standardized prevalence of prostate cancer was 3.32% (3.81% (n=52) and 2.95% (n=61) among farm and non-farm resident men). Farming job and farming duration did not have a statistically significant association with prostate cancer. A trend was observed for men who had work place exposure to insecticides and fungicides collectively and radiation to have an increased risk in comparison to men without these exposures. Personal smoking history, history of smoking pack years and family history of cancer modified the relationship between residence and prostate cancer. Age of an individual (≥ 65 years) was the strongest and most consistent risk factor of prostate cancer. Other factors such as marital status, household income adequacy, history of cardiovascular disease may also be associated with prostate cancer. The results may help research professionals by directing the focus of their research towards rural population examining prostate cancer.

Le cancer de la cavité orale représente un problème important de santé publique en France où les taux d’incidence sont parmi les plus élevés au monde. Bien qu’une détection précoce soit possible, ces tumeurs sont souvent diagnostiquées à un stade avancé et sont ainsi responsables de plus de 1500 décès par an. L’objectif général est de clarifier le rôle et l’impact des différents facteurs de risque dans la survenue des cancers de la cavité orale en France, notamment d’examiner de façon détaillée le rôle du tabac et de l’alcool par localisation anatomique précise, et d’étudier les associations avec d’autres facteurs de risque potentiels (indice de masse corporelle, antécédents médicaux, antécédents familiaux de cancer, consommations de café et de thé). Ce travail s’appuie sur les données d’une large étude cas-témoins en population générale, l’étude ICARE. Il porte sur un sous-ensemble de ces sujets (772 cas de cancer de la cavité orale et 3555 témoins). Les résultats montrent que le tabac augmente le risque de cancer de la cavité orale même pour des quantités et/ou durées faibles, alors que l’augmentation de risque liée à l’alcool n’est observée que pour de fortes consommations. L’effet conjoint du tabac et de l’alcool est plus que multiplicatif. Les associations avec les consommations d’alcool et de tabac varient selon la sous localisation : les associations les plus fortes sont observées pour le plancher buccal, les plus faibles pour les gencives. L’étude des autres facteurs de risque a mis en évidence : une association inverse entre risque de cancer de la cavité orale et indice de masse corporelle, avec un risque plus faible chez les personnes en surpoids ou obèses ; un risque augmenté lorsqu’un parent du 1er degré a été atteint d’un cancer des voies aéro-digestives supérieures ; un risque élevé chez les personnes présentant des antécédents de candidose buccale ; un risque diminué chez les consommateurs de thé ou de café. A partir de ces premiers résultats, il est envisagé de construire un score prédictif de cancer de la cavité orale permettant d’identifier les sujets à risque élevé sur lesquels cibler préférentiellement les actions de dépistage. / Cancer of the oral cavity is a major public health problem in France. Incidence rates are among the highest in the world. Although early detection is possible and effective, these tumors are often diagnosed at an advanced stage and are thus responsible for over 1,500 deaths per year. The objective of this work was to clarify the role and impact of several risk factors in the development of cancers of the oral cavity in France, particularly to examine the role of tobacco smoking and alcohol drinking by subsite, and to explore associations with other potential risk factors (body mass index, medical history, family history of cancer, tea and coffee consumption). We analyzed detailed data from 772 cases of cancer of the oral cavity and 3555 controls included in a large population-based case-control study, the ICARE study. Tobacco smoking increased the risk of oral cavity cancer even for low quantities and/or durations, while alcohol drinking increased this risk only in heavy drinkers. The combined effect of tobacco and alcohol was greater than multiplicative. Associations with alcohol and tobacco consumption varied depending on subsite: the strongest associations were observed for the floor of the mouth, the lowest for the gums. The analysis of other risk factors showed: an inverse association between oral cancer risk and body mass index with a lowered risk among overweight or obese; an increased risk associated with an history of head and neck cancer in 1st degree relatives; an elevated risk in people with a history of oral candidiasis and a decreased risk among consumers of tea or coffee. From these first results, it is planned to develop an oral cancer risk score to identify high-risk individuals for screening.