Objective
Several factors that are related to ovulation are relevant to ovarian cancer risk,
but it is unclear whether they can be included in a single definition of years of
ovulation.
Study design
We considered data from 2 case-control studies of ovarian cancer that were conducted
in Italy and included 1822 histologically confirmed cases and 4631 control subjects
who were hospitalized for acute conditions.
Results
As compared with the lowest quartile, the odds ratios of ovarian cancer were 1.60
(95% CI, 1.31-1.95), 1.65 (95% CI, 1.34-2.03), and 1.81 (95% CI, 1.47-2.23) for increasing
quartiles of lifetime ovulatory cycles. For 1 year of ovulation avoided, the continuous
odds ratios were 0.975 (95% CI, 0.965-0.985) for total ovulatory cycles, 0.91 (95%
CI, 0.87-0.95) for parity-related anovulations, 0.90 (95% CI, 0.76-1.06) for abortions,
0.92 (95% CI, 0.87-0.97) for oral contraceptive use, 0.99 (95% CI, 0.96-1.03) for
age at menarche, and 0.97 (95% CI, 0.95-0.98) for age at menopause. Women who reported
high numbers of ovulatory cycles and family history of ovarian/breast cancers had
an odds ratio of 3.27 (95% CI, 2.44-4.36).
Conclusion
This study found that pregnancy and oral contraceptive use had a stronger protective
effect on ovarian cancer than other anovulatory factors.
Key words
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Article Info
Publication History
Accepted:
June 20,
2006
Received in revised form:
May 31,
2006
Received:
March 7,
2006
Footnotes
Cite this article as: Pelucchi C, Galeone C, Talamini R, et al. Lifetime ovulatory cycles and ovarian cancer risk in 2 Italian case-control studies. Am J Obstet Gynecol 2007;196:83.e1-83.e7
Reprints not available from the authors
This work was conducted with the support of the Italian Association for Cancer Research, the Italian League against Cancer and the Italian Ministry of Education (PRIN 2005).
Identification
Copyright
© 2007 Mosby, Inc. Published by Elsevier Inc. All rights reserved.
