Most types of cancers are not genetic. According to the American Cancer Society, only 5 to 10 percent stem from direct genetic mutations or defects. Every person has two sets of genes, one from each parent, and cancer only requires one mutated gene to be present.
Even with a single parent having a mutated gene that is passed on via sperm or eggs, this does not mean a child develops cancer later in life, notes Coriell Personalized Medical Collaborative. With mutated genes present, it is simply an increased risk factor. Discuss preventative measures with a primary care physician to help decrease the risk of receiving a cancer diagnosis.