I did a little research:
Two uncles and a brother with prostate cancer, but not your father—fits with what researchers call familial clustering. The risk of prostate cancer is influenced by both genetic inheritance and environmental/lifestyle factors, and it doesn’t always follow a neat pattern like eye color.
Here’s how it tends to work genetically:
Inherited risk genes: Mutations in genes like BRCA2, HOXB13, ATM, CHEK2, and others can increase prostate cancer risk. These mutations can be passed down from either parent. Having one doesn’t guarantee prostate cancer, but it raises lifetime odds.
Family history effect:
Having a father or brother with prostate cancer more than doubles your risk compared to men without a family history.
The risk is even stronger when multiple relatives are affected, especially if diagnoses happened at younger ages.
Why your father didn’t get it: Genetics aren’t destiny. Even if your family carries a mutation, not everyone who inherits it will develop cancer. That’s called incomplete penetrance—the gene raises risk but doesn’t guarantee disease. Lifestyle, environment, and pure chance also play roles.
Stronger pattern with brothers/uncles: Some research shows prostate cancer risk can be more strongly influenced by brothers and uncles than fathers, possibly because they share more similar environmental exposures and X-chromosome–linked genetic factors.