Risk of breast cancer associated with short-term use of oral contraceptives.

Abstract

OBJECTIVE:

To estimate breast cancer risk associated with short-term (<6 months) oral contraceptive use, and explore variation in estimates by use characteristics and medical, menstrual, and reproductive history.

METHODS:

We analyzed data from the Women's Contraceptive and Reproductive Experiences Study. Case subjects were white women and black women, 35-64 years old, diagnosed with invasive breast cancer in July 1994-April 1998. Control subjects identified by random-digit dialing were matched to case subjects by age, race, and study site. Conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS:

Overall, short-term oral contraceptive use was not associated with breast cancer risk (OR = 1.0; 95% CI = 0.8-1.1). However, significant interaction between short-term use and menopausal status led to an observed increased breast cancer risk in pre-menopausal women (OR = 1.3; 95% CI = 1.0-1.7) and a reduced risk in post-menopausal women (OR = 0.8; 95% CI = 0.6-1.0) associated with short-term use. The association was more pronounced in women with non-contraceptive reasons for use and underlying risk factors for breast cancer.

CONCLUSIONS:

These associations may result from underlying characteristics of users or unmeasured factors influencing duration of use and breast cancer risk.

• Authors: Suzanne G Folger, Polly A Marchbanks, Jill A McDonald, Leslie Bernstein, Giske Ursin, Jesse A Berlin, Janet R Daling, Sandra A Norman, Brian L Strom, Linda K Weiss, Michael S Simon, Ronald T Burkman, Kathleen E Malone, Robert Spirtas
• Journal: Cancer causes & control : CCC (Cancer Causes Control) Vol. 18 Issue 2 Pg. 189-98 (Mar 2007) ISSN: 0957-5243 [Print] Netherlands
• PMID: 17216547 (Publication Type: Journal Article, Multicenter Study, Research Support, N.I.H., Extramural, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Contraceptives, Oral

Topics

• Adult
• Breast Neoplasms (epidemiology)
• Case-Control Studies
• Contraceptives, Oral (adverse effects, therapeutic use)
• Female
• Humans
• Middle Aged
• Odds Ratio
• Risk
• SEER Program
• Time Factors
• United States (epidemiology)