How susceptible am I to cancer?

I think that your family's history is the best way to see what diseases you are most likely to be susceptible to. I do believe that in your case you will be more susceptible to cancer than someone that has a family history of someone who doesn't. My family has a history of weak hearts, therefore I am always worried about my heart, and when I am older I am going to get it checked out; this is what I do suggest you do. As the other poster suggested also. I do not think a "figure" or calculation can be given for your chances of getting cancer, but I do think that it will be something to get checked out.