April 14, 2011 9:22 am Fighting Cancer With Diet and Exercise A doctor says maintaining a healthy lifestyle can help prevent cancer, as well as extend the life of patients diagnosed with the disease. US & World Videos 1:43 Traces of bird flu virus found in 1 in 5 samples of pasteurized milk, FDA says 2:42 Mother, surrogate celebrate a perfect ending to their long journey 1:12 Watch: Why vaccines are contributing to improved public health 1:53 The Helix School in San Rafael growing with the community 3:33 Bay Area sees slight improvement in air quality, annual report shows