I used to work at Myriad Genetics on their lab software and believe me they don't give a single shit about anybody's health. They care about charging exorbitant amounts for testing and counseling. Remember, these tests do not definitely tell anybody they will get cancer. They are simply and statistical indicator.
What Myriad patented are not the genes themselves (EVERYBODY has them). What they patented are the pattern of specific mutations of the BRCA1 and BRCA2 genes. It is these specific mutations (nucleotide patterns) within the genes that MAY indicate the POSSIBILITY of cancer. You have to also consider the medical and family history of a specific patient and then make a guess as to what the probability of cancer will be in the future. It's never a yes or no answer.
To add insult to injury, the original research for finding the mutations of the BRCA1 and BRCA2 genes was done by the founders of Myriad at the University of Utah which is a state school. The public paid for the original research.