In an effort to determine the health habits and lifestyle factors that raise or lower an individual’s lifetime risk for cancer, a 20-year epidemiological study—called the Cancer Prevention Study (CPS)—has been launched by the American Cancer Society. This research effort will recruit 300,000 men and women between the ages of 30 and 65 years who have no previous history of cancer.
Every 2 years, study investigators will collect data from the subjects on diet, exercise, tobacco use, living environment, medical history, and other factors and track the occurrence of cancer in the cohort. Approximately 185,000 participants have been recruited thus far; recruitment is expected to be completed by December 2013.
CPS-3 is the latest in a series of epidemiological studies that have established numerous links between lifestyle and the risk of cancer:
- The Hammond-Horn Study, which ran from 1952 to 1955, included 188,000 US men and was the first large prospective study to examine the effect of cigarette smoking on death rates.
- CPS-1 ran from 1959 to 1972 and recruited approximately 1 million US men and women. It studied a large variety of lifestyle factors and their association with cancer.
- CPS-2, launched in 1982 and continuing today, includes 1.2 million subjects who have now been followed for 30 years and assesses numerous environmental and lifestyle factors.
- CPS-2 Nutrition Cohort, a subset of 185,000 persons recruited into CPS-2, hones in on diet and behavioral variables that may affect the risk for cancer.
Alpa Patel, PhD, strategic director of CPS-3, said that many exposures and habits common in daily life today are very different from those in the early 80s when CPS-2 began. Moreover, the CPS-2 population has aged and no longer includes young subjects. “To better inform cancer control and prevention today,” Patel said, “we need to continue with a contemporary population.” CPS-3 is designed to recruit a greater proportion of minority subjects than were included in CPS-1 or CPS-2.
Previous epidemiological studies from the American Cancer Society have resulted in the publication of more than 700 scientific articles that have established many of the environmental and lifestyle links to cancer that were unrecognized at the time, but taken for granted today:
- The link between cigarette smoking and lung cancer.
- The significant impact of being overweight or obese on risk of cancer occurrence and death.
- The impact of hormones, physical activity, diet, medications, and vitamins on cancer risk.
- The impact of air pollution on cardiopulmonary conditions, which helped prompt the Environmental Protection Agency to propose more stringent limits on particulate air pollution.
- The link between aspirin use and reduced risk of colon cancer.
- The link between postmenopausal hormone replacement therapy and various gynecologic cancers (such as ovarian cancer).
- The link between diabetes and cancers of the pancreas.
- The link between physical activity and lower risk of various cancers including breast, colon, and aggressive prostate cancer.
Patel said that much of the work in CPS-3 will build on what researchers learned previously about tobacco use and links between cancer and obesity. “Since the 1950s,” she said, “every generation has paid it forward so the next generation can live in a healthier world where we understand more about what causes cancer.”
If you know someone who might be interested in joining the CPS-3 study, go to the American Cancer Society website for more information and to determine eligibility.