"Only about 5% to 10% of all cancer cases are hereditary, meaning they are caused by an inherited gene mutation."

https://cancer.ca/en/cancer-information/reduce-your-risk/che...

No. This is 5-10% are from inherited genetic issues, not environment. And that is the canadian cancer society saying so, not a random website or drug company. 5-10% is a monumental number of cancers. If someone came out with a drug to reduce cancers across the board by 5-10% there would be talk at the Nobel commitee.