January 30, 2013
Study Links Breast Cancer Mutation To Early Onset Menopause
Connie K. Ho for redOrbit.com — Your Universe Online
Scientists from the University of California, San Francisco (UCSF) recently conducted a study that showed a significantly earlier onset of menopause for women who inherited a mutation in one of the breast cancer susceptibility (BRCA) genes. These genes, known as BRCA1 or BRCA2, are tumor suppressor genes, meaning that they prevent uncontrolled cell growth.
The BRCA1 and BRCA2 genes normally help maintain the stability of the cell´s DNA and assist in limiting uncontrolled cell growth. However, the National Cancer Institute (NCI) describes how harmful mutations in the BRCA1 and BRCA2 genes have been connected to breast and ovarian cancer in the past. Particularly for women who inherit any of these harmful mutations, it can result in greater risk of developing breast and/or ovarian cancer.
The UCSF team of investigators discovered that women who were carriers of BRCA 1 or 2 mutations started menopause at an earlier age (50 years) than women who did not have the mutations (53 years). Along with these findings, female carriers of the gene who were also heavy smokers (where heavy smoking was defined as smoking over 20 cigarettes per day) were found to begin menopause at an earlier age (46 years) compared to their counterparts who were not smokers. The scientists noted that smoking is believed to have a number of hormonal effects such as shifting menstrual cycles and estrogen levels.
The researchers explained that this is the first control study to look at the link between the BRCA genes and their relation to the onset of menopause.
"Our findings show that mutation of these genes has been linked to early menopause, which may lead to a higher incidence of infertility,'' explained the study´s senior author Dr. Mitchell Rosen, an expert in reproductive endocrinology and fertility at the UCSF Center for Reproductive Health and the director of the UCSF Fertility Preservation Center, in a statement."This can add to the significant psychological implications of being a BRCA1/2 carrier, and will likely have an impact on reproductive decision-making.”
For the study, researchers observed almost 400 female carriers of mutations in the BRCA gene in northern California. The researchers compared the onset of menopause in this group´s to 765 women in the same geographic location who did not carry the mutation. According to Reuters, the researchers specifically looked at women who entered menopause naturally rather than females who underwent surgeries prior to menopause and had their ovaries removed.
Most of the study´s participants were ethnically white because the majority of BRCA1/2 carriers in the UCSF cancer risk registry were white. The researchers say it is not yet clear whether the results can be applied to other racial or ethnic groups.
An article in Health says the researchers advised women to think about having children at a younger age.
"Women with the mutation are faced with challenges in reproductive choices,'' commented the study´s co-author Dr. Lee-may Chen, an associate clinical professor in the Department of Obstetrics, Gynecology and Reproductive Sciences. "These data may help women understand that their childbearing years may be even more limited by earlier menopause, so that they can make decisions about their reproductive choices and cancer risk-reducing surgery.''
Based on the findings, the researchers believe that further study is needed to determine whether there is a higher risk of infertility due to the mutation.
Other medical experts, however, believe that the results of this study should be taken with a grain of salt.
"This study does not mean that you can't have children, and it doesn't mean that you have less time than you thought you did," Ellen Matloff, a research scientist in genetics and director of Cancer Genetic Counseling at Yale Medical Group unaffiliated with the study, told Reuters. "I don't think anything I read in this study would suggest that (mutation carriers) need to move their plans up."
For those who are concerned about the possibility of BRCA1 and BRCA2 mutations, there are genetic tests available to test for the mutation. According to the Mayo Clinic, BRCA genetic tests are only given to individuals who have a high likelihood of inheriting the BRCA mutation due to personal or family history, or who have a specific form of breast cancer. This particular genetic test is not normally offered to women who have an average risk of developing breast or ovarian cancers. Blood samples are needed in order to complete the genetic testing, and it is also recommended that genetic counseling be obtained prior to and following the genetic tests.
To discuss these issues with health care professionals trained in genetics, visit the NCI´s Cancer Genetic Service Directory online.