The following is an interesting article from
Johns Hopkins.
Basically they did a statistical study and concluded that 2/3 of cancers were "bad luck" related to the length of life and the other 1/3 other contributing causes like genetics, environment, diet, etc.
I too have noticed that Goldens are more prone to cancer now than 30 years ago. We've had 5, two made it to 15+, one to 12, one to 10 and Jill is approaching 13 and healthy. I think expected the life span is closer to 10 than 7.
Maybe we need to add a few flat coated retrievers and water spaniels into the gene pool and mix European gene pool with American.
Doug, DVM