Cancer Genetic Testing…should we and why

Something I have been thinking about recently is genetic testing for cancer.  I have two daughters.  I have several nieces and nephews.  This impacts potentially, all of them.  Yet they are all silent.

Nobody wants to know.  Most days, not even me. I want this to all be over and I live happily ever after cancer free.  I promised my surgeon I would not worry.  So I am not going to ‘worry’ as much as I can, but I am going to be an ‘informed consumer’ I will call it.  Hopefully that will keep me alive longer rather than playing ignorant.

I have conducted some research myself, reading different web sites, mostly from Duke, NIH, John Hopkins.  I can understand most of it, but some of it is over my head.  Each cancer is so different, analysis of the numbers and comparisons are mind boggling. But here’s what I have learned simplified about BRCA1 and BRCA2 testing.  A lot of my curiosity on this started in 1988, when my good friend Olga, died from ovarian cancer.  Following her death, all three of her sisters succumbed as well.  I knew that at the time of her death, she had breast cancer as well but they weren’t even bothering to treat that, because the ovarian had control and was running the show.

Here’s what I think I know.  Feel free to correct me if I am wrong.

The names BRCA1 and BRCA2 stand for breast cancer susceptibility gene 1 and breast cancer susceptibility gene 2, respectively.  BRCA1 and BRCA2 are human genes that belong to a class of genes know as tumor suppressors.

In normal cells BRCA1 and BRCA2 help ensure the stability of the cell’s genetic material  and help prevent uncontrolled cell growth. Mutation of these genes has been linked to the development of hereditary breast and ovarian cancer.

Okay, so How do BRCA1 and BRCA2 gene mutations affect a person’s risk of cancer?

Not all gene changes, or mutations, are  harmful. Some mutations may be beneficial, whereas others may have no obvious effect. Harmful mutations can increase a person’s risk of developing a disease, such as cancer.

A woman’s lifetime risk of developing breast and/or ovarian cancer is greatly increased if she inherits a harmful mutation in BRCA1 or BRCA2.  This woman has an increased risk of developing breast and/or ovarian cancer at an early age  and often has multiple, close family members diagnosed with cancer.  In my case, there were no close family members with cancer, and I was older (One of the primary reasons for getting cancer is just aging after menopause).

Harmful BRCA1 mutations may also increase a woman’s risk of developing other cancers:  cervical, pancreatic, colon, and uterine.

Harmful BRCA2 mutations may additionally increase the risk of pancreatic cancer, stomach,gallbladder, bile duct and melanoma.

Men with harmful BRCA1 mutations also have an increased risk of breast cancer and, possibly, other male types of cancer.  However, male breast cancer, pancreatic cancer, and prostate cancer appear to be more strongly associated with BRCA2 gene mutations.

The likelihood that a breast and/or ovarian cancer is associated with a harmful mutation in BRCA1 or BRCA2 is highest in families with a history of multiple cases of breast cancer, cases of both breast and ovarian cancer, one or more family members with two primary cancers (original tumors that develop at different sites in the body), or a Jewish heritage (not in my case).  However, not every woman in such families carries a harmful BRCA1 or BRCA2 mutation, and not every cancer in such families is linked to a harmful mutation in one of these genes. Furthermore, not every woman who has a harmful BRCA1 or BRCA2 mutation will develop breast and/or ovarian cancer.  This is good to know, however it makes me wonder if testing is a good idea?? The other population I read about was, Norwegian heritage also contributes to this(that’s me).

According to estimates of lifetime risk, about 12.0 percent of women (120 out of 1,000) in the general population will develop breast cancer sometime during their lives compared with about 60 percent of women (600 out of 1,000) who have inherited a harmful mutation in BRCA1 or BRCA2. In other words, a woman who has inherited a harmful mutation in BRCA1 or BRCA2 is about five times more likely to develop breast cancer than a woman who does not have such a mutation.

Lifetime risk estimates for ovarian cancer among women in the general population indicate that 1.4 percent (14 out of 1,000) will be diagnosed with ovarian cancer compared with 15 to 40 percent of women (150–400 out of 1,000) who have a harmful BRCA1 or BRCA2 mutation.


So this all raises interesting questions.  Do we want to know or do we not want to know.  Its a simple blood test, but the testing is relatively expensive.  I have already had cancer. I am probably going to assume I do have some DNA mutations somewhere, but am I going to do anything?  I don’t know.  What should I do?  Take off the other breast, remove my ovaries?  My kids are grown, I don’t know that I care for me.  But I might care for them.  They could be proactive, and potentially know about the possibilities, and make choices.

My choices have already been made.  They were made by a generation of relatives that didn’t talk about illnesses or share information.  It might not have made any difference anyway. But it would have been nice to have known.

Now you know.  Don’t be an ostrich with your head in the sand.  Share health information!  Somebody’s life may depend on it.  I take that back, many people’s lives depend on it.  This information contributes to research, and the future generations.

I have given you some things to think about.  If you have other valid information that may help, please feel free to add comments.  I have followers that are Jewish, and they may have more information than I found.  Thank you all.

About Bonnie

Breast Cancer survivor owned by one old Shelty and a 3 pound Yorkie named Mimzy!
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