Abstract
Authors:
1Departments of Preventive Medicine and Obstetrics and
Gynecology, Keck School of Medicine, University of Southern California,
Los Angeles, California; the University of Texas School of Public
Health, Houston, Texas; the Obstetrics and Gynecology Epidemiology
Center, Brigham and Women's Hospital, and the Harvard T. H. Chan School
of Public Health, Boston, Massachusetts; the Department of Public Health
Sciences, the University of Virginia, Charlottesville, Virginia; the
Division of Cancer Epidemiology, German Cancer Research Center,
Heidelberg, and the University Cancer Center Hamburg, University Medical
Center Hamburg-Eppendorf, Hamburg, Germany; the Department of
Epidemiology, the Geisel School of Medicine at Dartmouth, Hanover, New
Hampshire; Women's Cancer, Institute for Women's Health, University
College London, London, United Kingdom; the Center for Cancer Prevention
and Translational Genomics and Cancer Prevention and Control, Samuel
Oschin Comprehensive Cancer Institute, the Department of Biomedical
Sciences, and the Community and Population Health Research Institute,
Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los
Angeles, California; the Department of Chronic Disease Epidemiology,
Yale University School of Public Health, New Haven, Connecticut; the
Department of Obstetrics, Gynecology, and Reproductive Sciences,
Division of Gynecologic Oncology, University of Pittsburgh School of
Medicine, the Department of Epidemiology, University of Pittsburgh
Graduate School of Public Health, and the Women's Cancer Research
Program, Magee-Womens Research Institute and University of Pittsburgh
Cancer Institute, Pittsburgh, Pennsylvania; the Department of Cancer
Prevention and Control, Roswell Park Cancer Institute, Buffalo, New
York; the Department of Obstetrics and Gynecology, Duke University
Medical Center, Durham, North Carolina; the Department of Epidemiology,
University of Washington, and the Program in Epidemiology, Division of
Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle,
Washington; the Department of Virus, Lifestyle and Genes, Danish Cancer
Society Research Center, and the Molecular Unit, Department of
Pathology, Herley Hospital, and the Department of Gynecology,
Rigshospitalet, University of Copenhagen, Copenhagen, Denmark; the
Cancer Epidemiology Program, University of Hawaii Cancer Center, and the
Department of Obstetrics and Gynecology, John A. Burns School of
Medicine, University of Hawaii, Honolulu, Hawaii; the Department of
Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center,
New York, New York; and the Department of Epidemiology, University of
Michigan School of Public Health, Ann Arbor, Michigan.
OBJECTIVE: To describe the association between
postmenopausal estrogen-only therapy use and risk of ovarian carcinoma,
specifically with regard to disease histotype and duration and timing of
use.
METHODS: We conducted a pooled analysis of 906 women with
ovarian carcinoma and 1,220 women in a control group; all 2,126 women
included reported having had a hysterectomy. Ten population-based
case-control studies participating in the Ovarian Cancer Association
Consortium, an international consortium whose goal is to combine data
from many studies with similar methods so reliable assessments of risk
factors can be determined, were included. Self-reported questionnaire
data from each study were harmonized and conditional logistic regression
was used to examine estrogen-only therapy's histotype-specific and
duration and recency of use associations.
RESULTS: Forty-three and a half percent of the women in
the control group reported previous use of estrogen-only therapy.
Compared with them, current or recent estrogen-only therapy use was
associated with an increased risk for the serous (51.4%,) and endometrioid (48.6%,) histotypes. In addition, statistically
significant trends in risk according to duration of use were seen among
current or recent postmenopausal estrogen-only therapy users for both
ovarian carcinoma histotypes (Ptrend<.001 for serous and
endometrioid). Compared with women in the control group, current or
recent users for 10 years or more had increased risks of serous ovarian
carcinoma (36.8%,) and endometrioid ovarian
carcinoma (34.9%,).
CONCLUSION: We found evidence of an increased risk of
serous and endometrioid ovarian carcinoma associated with postmenopausal
estrogen-only therapy use, particularly of long duration. These
findings emphasize that risk may be associated with extended
estrogen-only therapy use.