Possibility vs. Probability

I find myself considering the word probability… with a BRCA2 mutation, the probability of getting breast cancer in my lifetime is as high as 85% and ovarian cancer as high as 27%. Not every woman who has a harmful BRCA1 or BRCA2 mutation will develop breast and/or ovarian cancer. Which makes this all incredibly confusing.

Possibility is the condition or fact of being possible. The Latin origins of the word hint at ability. Possibility also refers to something that “could happen”, that is not precluded by the facts, but usually not probable.

Probability is a measure or estimation of how likely it is that something will happen or that a statement is true. Probabilities are given a value between 0 (0% chance or will not happen) and 1 (100% chance or will happen). The higher the degree of probability, the more likely the event is to happen, or, in a longer series of samples, the greater the number of times such event is expected to happen.

Between visits to my genetic counselor, reading the book Positive Results, researching  information (eg BRCA FAQs here), and talking to others who have gone through this themselves, my husband and I are confronting the probability head on… (yes, I am the luckiest girl in the world to have a husband who is right beside me and in this with me together).

I’ve never been good at math. But look, I get it. I will probably get breast and/or ovarian cancer by the time I’m 70, if not before. I have choices now that I know this. I can avoid a diagnosis altogether. But there’s still more research to do.

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