National Cancer Institute
Back to previous page

Clue Cohort Study- Clue I (CLUE I )

Cohort Collaboration Contact

If interested in collaborating with the cohort on a project, please contact:

Principal Investigators

  • Kala Visvanathan (Johns Hopkins University)
Cohort Website

CLUE I - Campaign Against Cancer and Stroke
From August through November 1974, the Campaign against Cancer and Stroke was conducted in Washington County, MD. Referred to as CLUE I (from the slogan "Give us a Clue to Cancer"), the study was designed to collect blood samples from as many volunteers as possible to provide specimens for a serum bank, to "find out if certain substances in blood serum appear before the onset of cancer and other important diseases". Mobile trailers were stationed in a wide variety of locations in an effort to give all segments of the community ample opportunity to participate. Among the total of 26,145 persons participating, 23,950 were county residents. Linkage of the records from this program to those of a private census in the summer of 1975 indicated that almost one third of the adult population of the county had participated. Eighty three percent of CLUE I Washington County residents participated in the 1975 county census providing household data, including smoking, pets, fuel, and drinking water sources. From the supplemental census data a socioeconomic index code and passive smoking code have been determined.

CLUE I participation was best in the age group 35 to 65 years, and was slightly better among females, the better-educated, and nonsmokers. A brief medical history form was completed at the time of blood collection. A medication history (including use of vitamins and hormones) and blood pressure were taken. Blood was drawn into 15 ml Vacutainers, allowed to clot, refrigerated until it was centrifuged, and two 6 ml aliquots of serum were removed for storage at -70°C. The time from blood draw to freezing was usually only a few hours, and never more than 24 hours.

Among the CLUE I participants, 7849 cases of cancer have developed, with serum remaining from 96 percent of the cases.

Over a third of the participants in CLUE I also participated in CLUE II in 1989 (9111) with 8394 forming the Odyssey Cohort. DNA has been extracted for 99% of the Odyssey Cohort.
For those in CLUE I and II, data obtained in 1974 and 1989 included age, marital status, time since last menstrual period, smoking history, blood pressure, medication use, hormone use, height and weight and at age 21 (from CLUE II baseline), and dietary data from a food-frequency questionnaire (from CLUE II baseline).