Hi George,
I just wanted to recommend a (free online) cancer book:
http://stevefrank.org/cancer/cancer.html by a guy named Steve Frank who's an evolutionary biologist in California. I've read his two other books on social evolution and infectious diseases (which I study), and they're both great at concisely synthesizing the fields in a clear, 'big-picture' sort of way like few people can. Anyway, I've never actually read the cancer one, but I'm sure it's also great and frames the problem with an evolutionary perspective.
Best,
Dan