As the average life expectancy increases, there are increased opportunities for the emergence of diseases of older age, including cancers.
It's all about quality of life. We've learned how to extend life, we still aren't especially learned in how to extend quality of life. Longevity on its own is a poor statistic. We are very adept at prolonging life for years using machines and intravenous concoctions. I personally do not look forward to living 10-15 years in a quasi-lucid state in a nursing home or managed care facility as my grandparents did. I hope and believe it's realistic that we will improve the quality of life for our elderly, especially if we get past some of our moral and ethical turpitudes.
There is really no such thing as death with dignity. But I respect those who choose to end their life while they are in full control of their mental faculties rather than live their last years in either perpetual pain, narcotics induced oblivion, or child-like dementia. And whether I'm 75 years old or 200 years old, I personally would never choose such a thing. And when that time comes, I've already made my peace and will do what I feel honorable, longevity statistics be damned.