in people under 45 years of age. Almost 9 out of 10 cases of oesophageal cancer can be linked to lifestyle and environmental factors. Smoking and drinking alcohol Smoking tobacco and drinking a lot of alcohol are some of the main risk factors for oesophageal cancer. Cigarettes contain nitrosamines and other chemicals that increase the risk of cancer. Pipe smoking also increases the risk of oesophageal cancer. When you smoke, you always swallow some of the smoke as well as breathing it into your lungs. If you smoke and regularly drink more than the recommended limit (3 units of alcohol a day for men and 2 units for women), your risk of squamous cell carcinoma is greater. The combined risk is greater than the risk of just smoking plus the risk of just drinking. But your risk gradually starts to reduce after you stop smoking or drinking. Chewing tobacco, snuff or betel quid (also called paan or pan) also increases your risk of cancer of the oesophagus. Obesity Obesity means being very overweight. Body mass index (BMI) is a simple way of classifying whether people are the right weight. It looks at weight compared to height. Obesity is when a person has a BMI of 30 or higher. Every 5 unit increase in BMI (for example a BMI of 25 to a BMI of 30) increases the risk of adenocarcinoma of the oesophagus by more than half. A Cancer Research UK study estimated that being overweight and obesity causes more