Iowa Women's Health Study: Epidemiology of Cancer in a Cohort of Older Women

Lead Contact and/or Principal Investigator (PI):

  • DeAnn Lazovich, Ph.D., M.P.H.
    University of Minnesota School of Public Health
  • Kim Robien, Ph.D., R.D.
    George Washington University School of Public Health

Funded Since: 1985
Funding Source: NCI Extramural Program (Epidemiology and Genomics Research Program, Division of Cancer Control and Population Sciences; CA039742External Web Site Policy)
Year(s) of Enrollment: 1986
Study Website: http://www.cancer.umn.edu/research/prevention-and-etiology/research-studies/index.htmExternal Web Site Policy

Cancer is the second leading cause of death in postmenopausal women, and detailed epidemiological investigations are warranted to identify etiologic factors, including potentially modifiable risk factors. The Iowa Women's Health Study (IWHS) recruited a population-based cohort of 41,837 Iowa postmenopausal women, ages 55 to 69 years in 1986, to determine whether diet, body fat distribution, and other risk factors were related to cancer incidence.

Over the years, participants have completed up to six mailed questionnaires to collect data on exposures and lifestyle factors. Cancer incidence and mortality have been ascertained since 1986 by linkage with the State Health Registry of Iowa, which is part of the NCI-funded Surveillance, Epidemiology, and End Results (SEER) Program; the National Death Index; and the Centers for Medicare and Medicaid Services (CMS) claims data.

By the end of 2010, the investigators will have extended follow-up for site-specific cancer incidence and mortality through 22 years (2007). A total of 11,517 first primary cancers had occurred in the cohort by the end of 2006, and among the 38,006 women who were cancer free at baseline, 10,394 had developed primary cancers. The wealth of data on the cohort is enabling investigators to conduct analyses in four broad areas to test hypotheses on:

  • potential risk factors for uncommon cancers not yet studied in this cohort;
  • unexamined potential risk factors for incident common cancers;
  • risk factors for incident cancers examined in a limited fashion previously; and
  • potential contributors to better survival from breast, colorectal, ovarian, or uterine cancer.

This research project is providing valuable information on the risk and survival of cancer in older women. With the number of Americans over age 65 on the rise, the cohort is becoming increasingly informative with respect to findings on less common cancers and lifestyle predictors of cancer occurrence and survival among the elderly.

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