U.S. cancer group launches mass cancer study

WASHINGTON (Reuters) - The American Cancer Society said it was looking for half a million volunteers willing to let researchers watch them for the next 20 years to see if they get cancer.

The aim is to match similar big studies in Europe and Asia that are looking on a large scale for the environmental and lifestyle factors that cause cancer, the second-leading cause of death in the United States after heart disease.

"This type of study involves hundreds of thousands of people, with diverse backgrounds, followed for many years, with collection of biological specimens and assessments of dietary, lifestyle and environmental exposures," Eugenia Calle, managing director of analytic epidemiology at the American Cancer Society, said in a statement.

"It also requires active follow-up to discover if and when study participants develop cancer."

The group will recruit men and women between the ages of 30 and 65 who have never been diagnosed with cancer. They will give blood to be tested and answer questionnaires at various times over the next 20 years.

Similar big studies have confirmed the link between cigarette smoking and lung cancer, shown that obesity increases the risk of several cancers, and linked aspirin use to a lower death rate from colon cancer.

They have also found evidence that defied conventional wisdom, such as the Women's Health Initiative study that found hormone replacement therapy actually raises the risk of breast cancer, stroke and heart attack.