Researchers at the recent European Breast Cancer Conference said that up to one-third of cases could be prevented by a healthier diet and exercise regime. "Better treatments, early diagnosis and mammogram screenings have dramatically slowed breast cancer, but experts said the focus should now shift to changing behaviors like diet and physical activity. 'What can be achieved with screening has been achieved. We can't do much more,' Carlo La Vecchia, head of epidemiology at the University of Milan, said in an interview. 'It's time to move on to other things.' La Vecchia spoke Thursday at a European breast cancer conference in Barcelona. He cited figures from the International Agency for Research on Cancer, which estimates that 25 to 30 percent of breast cancer cases could be avoided if women were thinner and exercised more. The agency is part of the World Health Organization. His comments are in line with recent health advice that lifestyle changes in areas such as smoking, diet, exercise and sun exposure can play a significant role in risk for several cancers."