You are one of the world's foremost experts on cancer prevention. How to prevent cancer? Dr. Anton Titov, MD. How to minimize and decrease the risks of developing cancer? It's an interesting question. I mean we know very clearly that the single most important avoidable cause of cancer is tobacco use. Dr. Jack Cuzick, PhD. There have been dramatic improvements in the developed world in reduction of cigarette smoking. This is shown dramatic reductions in lung cancer incidence. So cessation of smoking is crucial to any cancer prevention. Dr. Anton Titov, MD. Smoking, we know, is a major cause of cancer. There are other measure to prevent cancer. We don't have quite such clear evidence for them. But there are clear benefits for several other strategies to prevent cancer. Avoid obesity. Remain physically active. There is a clear evidence that obesity is associated with cancer. There is clear evidence that physically active people get less cancer than those that don't exercise regularly. So those things we can be pretty certain they're important. Dr. Jack Cuzick, PhD. How to improve a person's lifestyle is major area of concern. I think we have been very unsuccessful in avoiding the obesity epidemic. Obesity a major public health problem. Here at the Wolfson Institute of Cancer Prevention in London we work to control the amount of sugar that we allow into our diet. Sugar is a major cause of obesity, diabetes, cancer, and cardiovascular disease. So we need to do more to control intake of sugar. I think that's a recent problem. We do need to find ways to control sugar consumption. Keeping physically active is good for a range of diseases. Only one of them is cancer. If you keep physically active, you feel better, cardiovascular diseases is also reduced. So I think that's useful. Screening for cancer is important. We know that cancer screening works. Dr. Jack Cuzick, PhD. There is very clear evidence that screening for cervix cancer, for breast cancer, for colorectal cancers is important. Prostate cancer screening is a challenge. It probably does prevent disease. But we have this major challenge of excessive treatment of prostate cancer. This problem has led many physicians and researchers to say this. We are probably not ready to do screen for prostate cancer routinely until we get a better understanding of how to treat early lesions. This is probably the major strategy of cancer prevention. The other major cancer prevention strategy is Aspirin. Dr. Jack Cuzick, PhD. We are not doing very much about promoting aspirin use for cancer prevention. 10% reduction of all cancer incidence and mortality by aspirin would be a huge step forward. We do appear to have the means to do that. I think one of our challenges for the near future is this. We to make cancer prevention strategies work for things that we do know work. In terms of diet, I think we're still a long way from any clear understanding. We know that overeating and becoming obese is a bad idea for health. But all of these ideas about specific aspects of diet have not really resulted in reducing cancer. There's a belief that vitamin A and beta-carotene could prevent cancer. Large clinical trials were done in people at high risk of lung cancer because of smoking. Vitamin A had no benefit for lung cancer prevention. Vitamin A had a slightly harmful effect on lung cancer risks. More recently, there is the SELECT clinical trial in the United States.This clinical trial investigates vitamin E and selenium as a cancer prevention strategy. Epidemiology suggested that Selenium and Vitamin E might reduce cancer. But supplementation of diet with vitamin E and selenium has not led to reduction in cancer. In fact, it increased some cancers. So our understanding of what specific dietary factors are important is really quite limited. Dr. Jack Cuzick, PhD. There is also some evidence that red meat is associated with the rectal cancer. Processed meats may increase risk of colorectal cancer. But again, that's a very small effect overall. Alcohol does cause some cancers. There is a real question about to what levels would you reduce alcohol consumption. I don't think we're going to become an alcohol-free society. But certainly limiting your alcohol intake makes a lot of good sense. We don't want cancer prevention to become an obsession. Clearly, enjoying life is important. But it's important to not do things that can have a major negative impacts. So you can't enjoy your life. Dr. Jack Cuzick, PhD. So my personal view is this. You find out the major cancer prevention strategy. You do certain things that have impact on cancer. You try to avoid cancer-causing actions. And then you live your life otherwise as happily as you can! Macmillan Cancer Support estimates that almost 50% of all people will get cancer during their lifetime. Dr. Anton Titov, MD. You are a major authority on cancer prevention. Is there anything else you would like to add to our conversation? Dr. Jack Cuzick, PhD. I think there are several reasons that cancer is becoming more common in terms of percentage of population. Because we had really quite big successes in preventing cardiovascular disease. People die eventually and get some disease. So just looking at the proportion of the population who get cancer isn't the whole story. It's important to delay diseases as late as possible. We're all going to die at some stage. So we're not going to become completely cancer-free. Dr. Jack Cuzick, PhD. But getting cancer when you are 90 years old is less of a problem than getting cancer when you are 40 or 50. Professor Cuzick, thank you very much for this very interesting conversation. Dr. Anton Titov, MD. We're looking forward to continue seeing results from your international clinical trials and your leadership! Thank you very much! Thank you!