You are so right. I watched my brother die of lung cancer at the age of 54. I had quit more than four years prior. He had actually quit several years earlier, and just decided he wanted to go back to smoking!!! He quit again just before he was diagnosed, and died a year later ... on my birthday.
Pretty similar with my dad, quit smoking at age 50, lung cancer at 54 and "beat" it. Diagnosed with a brain tumor at age 55, didn't beat it, and died on his birthday.