Talking about Breast Cancer

Do You Have a Story?

How have you been affected by breast cancer? Tell us your story and help all of us learn more about the disease.

(To share your story, please leave a comment at the end of this post. 23andMe customers can also share their stories in our Breast Cancer Community Group.)

Roughly one in eight women faces breast cancer at some point in her life and nearly everyone has a mother, sister or friend who’s been diagnosed with it. These statistics are staggering and really demonstrate that breast cancer touches everyone.

As a genetics company, 23andMe is invested in understanding how genetics influences the development of cancer and how people respond to treatment (see bottom of post). But we’re motivated most of all by the stories we hear from people whose lives are impacted by the diseases we study. Below are two stories from women affected by breast cancer.

Jill’s 23andMe results came back in 2010 reporting a mutation in the BRCA1 gene, which can significantly raise a person’s lifetime odds of developing breast cancer. She and her husband then met with a genetic counselor and had the test redone by another genetic testing company only to get the same result.

This knowledge combined with her family history of cancer prompted Jill to meet with specialists and see what could be done to avoid developing the disease. Jill elected to have a double mastectomy, which decreases the odds of developing breast cancer. Said Jill, “the decision to have the double mastectomy, although it was scary, was actually pretty easy to make…Once I found out I was BRCA positive I felt I was in a lucky position to fight cancer before I ever got cancer.”

23andMe customers can view their results for the three BRCA1 and BRCA2 gene mutations that are most common in individuals with Ashkenazi Jewish ancestry in their BRCA Cancer Mutations report. You can also view your results for breast cancer based on common genetic variations.

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Joy is a breast cancer survivor who also lost both her mother and a sister to breast cancer. In order to find out if she had passed a genetic risk for the disease to her children she purchased 23andMe’s Personal Genome Service. She also paid the more than $3,000 it costs for complete BRCA screening. “I was two or three months into treatment and I figured I must be carrying the (variant),” Joy said.

It turned out that neither test pulled up a mutation in either the BRCA1 or BRCA2 genes. Although BRCA mutations account for most but not all inherited breast cancers in women, they still only explain a small fraction of total breast cancer cases.

Genetics of Breast CancerRoughly five to 10 percent of breast cancer cases occur in women with a genetic predisposition for the disease. Mutations in either the BRCA1 or BRCA2 genes account for most but not all inherited breast cancers in women and based on recent literature are associated with a lifetime risk of about 50-60% (previous estimates were around 80%). Genetic variation in other genes — for instance PTEN, TP53 and CHEK2 — has also been associated with breast cancer risk.

Non-genetic factors and mutations in other genes can also influence risk (see sidebar for more information). Still, for Joy, it was a relief to know that she isn’t passing one of the BRCA mutations to her children. “It was a revelation in that I assumed I had the (variant),” she said.

23andMe is intended for research and educational purposes only.  23andMe’s services are not a substitute for professional medical or diagnostic advice.

Research on the Genetics of Response to Treatment for Breast Cancer
23andMe and Genentech launched the InVite Study to understand how genes influence response to treatment for metastatic breast cancer. Enroll at or email [email protected] for more information.

Potential findings of this study may help to explain why some women respond well to certain drugs while others suffer adverse side effects.

  • Cheryl Morris

    At 45, my doctor informed me that I had “failed my mammogram” and I went into a tizzy. My mom had died from metastatic breast cancer when she was 50 and we knew nothing of her heritage, as she was adopted. Luckily, I could have a lumpectomy and radiation [this was 1985] and I did so. But, I worried about my daughter. Had I given her a time bomb?

    Years pass and now I can have a test for BRCA1 and 2 and, luckily, my doctor and plan pay for it. “What outcome do you want?” asked the genetic councilor? “I don’t want both!” Well, lucky me, I have neither. Now we are to the time of 23andme and I get tested. Still negative for the markers for BRCA1 and BRCA2. I pay for my daughter’s testing and thankfully she, too, is negative.

    But why did I get breast cancer and why did my mom get it? That is the big unknown. But the genetic counseling I got was useful, as in 2006, I found that I had uterine cancer. I had had several years to mull over the possibility of ovarian cancer and its prevention and it made it very easy to tell my surgeon that I wanted a total hysterectomy. It was done and so far, I’m OK.

    Are the two types of cancer I had related in some way? Who knows, but maybe 23andme will find out!

  • Jake

    The sta,t 1 in 8, is very scary to think about. That alone should get women more proactive about taking care of checkups etc. The benefits of the 23andMe tests are endless.

  • tom

    @ Jake

    And men need to start getting attention directed at prostate cancer. It is just as deadly as breast cancer but only receives a fraction of the funding.

  • Aimee

    At the age of 40 I was diagnosed with triple negative DCIS breast cancer. One maternal Aunt was diagnosed over 20 years ago, also at the age of 40. My mother was diagnosed about 15 years ago. Both of them were or one negative. My other maternal Aunt was diagnosed with triple negative last December. My sister, the Aunt that currently has cancer and I all have tested negative for the BRCA 1 & 2. Fron what I know about our family history we are anglo Saxon and native American but triple negative is only about 10% of all breast cancers and mainly found in African American, Caribbean and Latina people. I find it hard to believe there is not a genetic link and wish my mom had paid for the testing when insurance wouldn’t.

  • Clarissa

    There are several legacy genetic diseases that have been passed down through the ancestral lines of New Mexico. One of them is BRAC1 185delAG, a 2,000 year old knowned Ashkenazi mutation for breast and ovarian cancers, which also has been linked to an aggressive form of prostate cancer. Two other prevalent legacy diseases are CCM and OPMD, and there are more.

    It is unfortunate that doctors, medical centers and researchers seem to think it is mostly today’s northern NM people with higher incidences without taking into consideration how NM family dynamics were influenced by the fighting over and the loss of land grant rights after the Treaty of Guadalupe Hildalgo and what effects the Civil War had on NM. NM people moved to greater populated areas and migrated to other states after these two big historic factors.

    My NM ancestors moved several times since the start of the Civil War and ended up in NE Arizona in the 1870s. Due to the Great Depression, many moved from NE AZ to other areas in Arizona and onto California in look for work. There are many of these Hispanic people know little of their ancestral lineages.

    What they are more ignorant of is the genetics dynamics of the recognized NM legacy diseases that may have been passed down to them. The medical community in other states with large Hispanic populations have not made the effort to connected the dots for those of Hispanic descent living in their states.

    I know of several cousins who have had breast, ovarian and prostate cancer and none of them have been genetically tested for any of the BRAC1 and BRAC2 mutations. I do ask. Those who develop prostate cancer are grossly overlooked.

    What is it going to take to wake up the medical field about these Hispanic genetic dynamics of those who may not know they are descended from many of the original Hispanic families of NM?

    It should be a medical criteria to check into the genetic dynamics of any Hispanic person with familial roots in the Southwest who has been diagnosed with one of these types of cancers.

    I have been talking about this for more than eight years now (I have researched the genealogies for so many Arizonans with NM roots), yet I cannot seem to get the Southwest US medical community to take notice.

    Is this a criteria that the researchers for 23andme would be willing to get behind and push?

  • marty

    aimee, what does triple negative mean? and what does one negative mean also?

    • BethannH

      Hi Marty,

      Thanks for your comment. Triple-negative breast cancer is defined as estrogen receptor-negative, progesterone receptor-negative, and human epidermal growth factor receptor 2-negative (usually just called HER2-negative). This just means that the cancer cells aren’t displaying the receptors (molecules on the surface of the cell) that most drugs target and for this reason it can be challenging to find a drug that will work on these cancers. Breast cancer comes in different forms and it’s becoming clear that it’s important to find out which kind you have because it can impact the course of treatment. As for the “one negative” line in Aimee’s comment, she might just be saying that both her aunt and mother also had triple-negative cancer. Thanks for reading.

  • 23blog

    I don’t know how to answer your question. First, I’m hopeful that your future is not bleak. It wouldn’t be appropriate for us to give you medical advice. Also your personal health history, your family history and your ancestry all would indicate that this is a risk for you. As for what 23andMe can do, we currently do not offer health reports to customers pending a regulatory review by the FDA of our health product. So at the moment our service would not help you in trying to determine your health risks for breast cancer.

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