multiple cancers over the last 10 years

I would like to find out if others have recurring issues with skin cancer? I have personally had over 25 skin cancers removed in the last ten years. I have had bout 15 sqamous cancers removed from my lip and lower face and arms. I have also had over 10 basal cell carcenomas removed from my upper face and nose. I had mohs surgery in 2005 with reconstruction due to the basal cell going to the nose. I have had 4 melanomas removed from top of my head and back. I have undergone topical chemotherapy 3 times and full chemo once. I have undergone radiation treatment and lost count of the surgieries. These started when I was 30 and too this day  (I am almost forty)  I am still having cancer cut off and treated.  when I ask my doctors they have no idea has to why cancer affects me so, So I would like to find out if anyone else has had similiar problems. Yes I did grow up in the tropics so I think sun has to be part of it and I have worked with jetfuel for most of my life, which I am sure is part of it too. But, This amount of skin cancer seems insane and very uncommon.