NORWALK - American Cancer Society officials say they are encouraged by the number of people in Connecticut and nationwide who've signed up to participate in a major cancer study.

The study will track for 20 years people who are currently cancer-free.

Cancer researchers will be looking at genetics, lifestyle and environmental factors in hopes of getting new information on what causes cancer.

Scientists now have blood and data from more than 300,000 people nationwide who have signed up for the Cancer Prevention Study-3.

The American Cancer Society's Michelle Wolf says many people who agreed to participate have lost loved ones to cancer and see this as a way to help with the fight.

Wolf says that in the first three studies they found a link between smoking and lung cancer, a link between obesity and cancer, and that having an aspirin a day could reduce the risk of colon cancer.