Would you have gene testing if it was affordable or even paid for by your insurance?

I’m talking about the screening tests available that tells you if you are likely to get breast cancer, prostate cancer, etc. Not a test that tells you that you have the disease.
I don’t know if I would want to know. And if you found out you had the gene, would you go ahead and have a mastectomy or whatever your test tells you that you have the gene?