Your risk of cancer can incrrease if another in your family has had cancer before.
Your Genetics only play in at your cancer risk at about 5%
Certain DNA is more likely to make weaker cells
These weaker cells have a higher chance to mutate
Cancer is a mutation therefore it could be caused by genetics
The DNA that is fragile to cancer is transferd to you from either your mother or father
This DNA gets copied along with other DNA
Which is how genetics is passed down through inheritance
These "Cancer Genes" work the same way as they did in your reletives
which puts you at a higher risk for cancer.
Thats how our parents cancer genes affect us with nothing but a higher risk