“Should I get BRACA testing?” is the question I'm asked most.
It's a good question and the conversations that unfold often reveal how little most people know about genetics. It's understandable because you, like me, probably have a vague recollection about a a monk and his pea plants. I aim to provide what I think is a simple and easy to understand overview of genetics. Then I'll explain what BRCA is and how it keeps you healthy.
Yes, it keeps you healthy because you and every human - man or woman - is born with the BRCA genes.
So why get tested for it? It's to see if your BRCA genes are working properly or not. At a very basic level, our body is equipped to combat cancer. Think of cancer as just a genetic error that the body should be well equipped to correct. At any given moment you may have thousands of cancerous cells in your body that your DNA is fixing, or allowing to die off. So let's talk about what your DNA is and does in a very basic manner.
BASIC TERMS
DNA is in its center of all our cells and every cell has the same DNA
DNA serves as an instruction manual with millions of instructional chapters
Those chapters are called genes
Genes provide instructions for what cells should become, what job they perform, how to behave, how to interact, and how to deal with stress (and you thought your parents were controlling)
Certain genes also control how our cells deal with cancer
...you're not getting tested “to see if you have the BRCA gene” you're getting tested to make sure your BRCA genes are working properly to protect you from cancer.
HOW CANCER OCCURS
Generally speaking, cancer is a disease of age and this post focuses on adult onset inheritable cancers, not child cancers. Cancer happens naturally as our cells don’t make perfect copies of their genes (aka instructions). Then those cells replicate themselves with the errors. As cells pass along errors more errors tend to accumulate. Think about when you make a photocopy of a photocopy.
An error could be in an instruction that normally tells your cells to stop making more of themselves, isn't working properly. If you're born with an error in one of those genes, an "onco-suppressor" gene, as other mutations build up through time and from environmental factors, that suppressor gene doesn't stop cancer from spreading like it should.
BRCA is a tumor-suppressing “oncogene” and technically there are two, BRCA1 and BRCA2. Most inherited alterations (also sometimes called mutations) are completely harmless. In fact almost 90% of patients who get tested are negative for a cancer-related mutation. If you are born with a cancer-related alteration there is no guarantee you'll get cancer but it is certain that your born with a lesser ability to slow and fight the development of certain cancers.
So you're not getting tested “to see if you have the BRCA gene” you're getting tested to make sure your BRCA genes are working properly to protect you from cancer.
...if you're a man, BRCA doesn't just cause "female cancers." It can cause male breast cancer ... prostate and pancreatic cancer
CANCER RISKS
Aside from BRCA1 and BRCA2, there are nearly 20 genes that are associated with breast cancer, and about 50 overall that has some control over cell growth that could elevate your risk of getting various types of cancer. Unfortunately no one gene is responsible for one cancer. BRCA, for example, may lead to earlier development of cancers of the breast, ovarian, prostate, pancreatic, or melanoma. Thus it's optimal to get a broad panel test than a narrow one.
Any doctor who says you don't need testing because they have you getting mammographies each year, may only be conducting 1/4th the appropriate screening. What about ovarian risk for positive patients? Or, if a physician says they will order a "breast cancer panel" genetic test is not accurate, as there is no such thing, and they should be explaining the option and benefit to you, so you can make the choice if a broader panel is what you want.
And if you're a man, BRCA doesn't just cause "female cancers." It can cause male breast cancer to the same degree as women of general population risk (~13%), prostate and pancreatic cancer. So yes, testing matters for your sakes and for the sakes of your children and family.
WHAT CAUSES DNA DAMAGE
There are essentially two ways that genes become damaged to a point where their instructions are ineffective. You are either born with an oncogene that has instructional errors (think spelling or grammatical errors). Or, you experience significant exposure to environmental factors that disrupt those instructions, and then when those cells divide, they replicate the problematic instructions; over and, and over, and over again. You probably guessed the environmental factors like smoking, overexposure to sun radiation, etc.
Without testing, you can't surely know what the best plan and options are for you
SUMMARY
That is the basic explanation of BRCA testing. If you’re getting BRCA testing you’re actually seeing if your cancer protection genes are working properly. Not if you have the genes. The test will not tell you if you have cancer, but it will help you and your provider plan out the precise screening and medical management plan you need to either catch cancer in the earliest stages so you can avoid gnarly treatments like chemo, or take preventative surgery options to drastically reduce your risk. Without testing, you can't surely know what the best plan and options are for you, and not knowing may possibly leave you worse off in the long run.
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