Title: Depot medroxyprogesterone acetate and breast cancer. A review of current knowledge.

POPLINE Document Number: 120192

Author(s):

Chilvers CE

Source citation:

DRUG SAFETY, 1996 Sep;15(3):212-8.

Abstract:

Although further epidemiological studies of the long-term effects of depot medroxyprogesterone acetate (DMPA) on breast cancer risk are needed, preliminary research results are reassuring. Pooled analysis of the results of two large case-control studies--the World Health Organization Study (involving women newly diagnosed with breast cancer in 1979-88 in Thailand, Kenya, and Mexico) and the New Zealand Study (comprised of women with breast cancer diagnosed in 1983-87)--has facilitated assessment of this association. Overall, 219 of the 1768 breast cancer cases and 1725 of the 13,905 controls had ever used DMPA (odds ratio, 1.1; 95% confidence interval, 0.97-1.4), with no increase in risk with increasing duration of use. Women under 35 years of age at diagnosis and those initiating DMPA use before 25 years of age had marginally statistically significant increases in breast cancer risk. The highest risks were recorded among women who had initiated DMPA use within 5 years of diagnosis. Risks declined with time since first use in all age categories. After 5 years since last use, DMPA use for more than 2 years was associated with a decreased risk of breast cancer. The raised relative risks in certain subgroups are difficult to interpret and may reflect surveillance bias. Enhanced understanding of the biology of breast cancer will aid interpretation of these results.

Keywords:

Literature Review
Case Control Studies
Depo-Provera
Breast Cancer
Risk Factors
Studies
Research Methodology
Medroxyprogesterone Acetate
Contraceptive Agents, Progestin
Contraceptive Agents, Female
Contraceptive Agents
Contraception
Family Planning
Cancer
Neoplasms
Diseases
Biology