Evidence-Based Practice on Whether the Use of Oral Contraceptives Influences the Occurence of Pre-Menopausal Breast Cancer in Women WHo Are Either Known to Have the BRCA1 or BRCA2 Mutation or not Known to Have the Mutation

Conley, Joyce, Sally Zeer, and Anita Shamoun

Breast Cancer is the most common type of cancer among women globally.  Additionally, about 150 million women worldwide use hormonal contraception. In women with the inherited BRCA1 or BRCA2 mutation, there has been an increased incidence of developing breast cancer before the age of 50 years.  Clinicians need to determine whether alternative birth control methods for these mutation carriers and non-carriers need to be explored, if indeed, a high correlation between oral contraceptives and increased risk of premenopausal breast cancer exists.

The purpose of this literature review is to determine whether premenopausal breast cancer incidence is increased in oral contraceptive users and help clinicians provide a plan of care by answering the clinical question: Does the use of oral contraceptives influence the occurrence of premenopausal breast cancer in women who are either known to have the BRCA1 or BRCA2 mutation or not known to have the mutation?  An extensive search of databases was conducted including PubMed, Science Direct, CIANHL, and Ebsco to obtain studies published in year 2005 to present.  Inclusion criteria contained key word searches such as oral contraceptives, pre-menopausal breast cancer, and BRCA1/BRCA2 mutations. A total of eight studies were found that met inclusion criteria.

The research showed that although some correlation was determined with a slight increased risk of breast cancer in oral contraceptive users, the results were deemed to be statistically insignificant, and a majority of the studies yielded inconsistent results.  BRCA1 or BRCA2 mutation carriers displayed greater inconsistency in regard to which mutation carrier posed a greater risk, if any at all.  Therefore, the review shows that further studies are recommended to clarify the risks of oral contraceptive use and increased risk of breast cancer among both BRCA1 or BRCA2 carriers and non-carriers in order for clinicians to change their current practice if need be.