The American Cancer Society's Cancer Prevention Study 3 (CPS-3): Recruitment, study design, and baseline characteristics.

BACKGROUND

Prospective cohort studies contribute importantly to understanding the role of lifestyle, genetic, and other factors in chronic disease etiology.

METHODS

The American Cancer Society (ACS) recruited a new prospective cohort study, Cancer Prevention Study 3 (CPS-3), between 2006 and 2013 from 35 states and Puerto Rico. Enrollment took place primarily at ACS community events and at community enrollment "drives." At enrollment sites, participants completed a brief survey that included an informed consent, identifying information necessary for follow-up, and key exposure information. They also provided a waist measure and a nonfasting blood sample. Most participants also completed a more comprehensive baseline survey at home that included extensive medical, lifestyle, and other information. Participants will be followed for incident cancers through linkage with state cancer registries and for cause-specific mortality through linkage with the National Death Index.

RESULTS

In total, 303,682 participants were enrolled. Of these, 254,650 completed the baseline survey and are considered "fully" enrolled; they will be sent repeat surveys periodically for at least the next 20 years to update exposure information. The remaining participants (n = 49,032) will not be asked to update exposure information but will be followed for outcomes. Twenty-three percent of participants were men, 17.3% reported a race or ethnicity other than "white," and the median age at enrollment was 47 years.

CONCLUSIONS

CPS-3 will be a valuable resource for studies of cancer and other outcomes because of its size; its diversity with respect to age, ethnicity, and geography; and the availability of blood samples and detailed questionnaire information collected over time. Cancer 2017;123:2014-2024. © 2017 American Cancer Society.