A Prospective Study of Diet and Cancer in Members of the American Association of Retired Persons

This is a prospective cohort study of diet and cancer in relation to several major cancers,
especially breast, prostate, and colorectal malignancies. The cohort comprises 50-69 year-old
male and female members of the American Association of Retired Persons (AARP). In 1995-6 we
mailed baseline questionnaires to 3.5 million AARP members. Over 615,000 AARP members
responded, with over 540,000 providing adequate dietary data. Preliminary analysis indicates
that the cohort, both men and women, has the desired wide distributions of percent calories
from fat, dietary fiber, fruits and vegetables, and red meat. Approximately 330,000 of the
initial respondents (with satisfactory data) returned a second questionnaire containing
questions on exposures not assessed in the first instrument.

In terms of field activities, the study has been relatively quiescent over the past year. At
the end of the five-year period of observation, we will mail to cohort members a brief
follow-up questionnaire primarily targeted to endpoint assessment. (Because of cancer
registry lag-time, we do not expect to mail this questionnaire until early 2002.) Follow-up
will be largely passive, through established state registries. The initial questionnaire
mailing will be to AARP members in those states selected on the basis of having registries
with adequate coverage and quality. We will use active follow-up, with record retrieval, for
the small percentage of cohort members who have moved out of the cancer registry areas. The
buccal cell collection pilot study has been completed; over 50% of those pilot study
partricipants who had completed the baseline and risk factor questionnaires returned buccal
cell speciments. Preliminary data from a pilot study of the end point ascertainment procedure
indicate that cohort incidence rates for major cancers, determined from registry data, are
consistent with SEER rates.