Ah, but you said immortality. Duplication and transfer is quite different. It is not immortality, but simply many mortalities.
That brings up a whole other set of issues regarding the recordability of thoughts and memories into a foreign body. In theory, one could create a computer of sorts that could read the brain's impulses, record them, and play them back or return them to an external source, and yet, where would they get this extra brain that would replace your previous one? Soft-tissue cloning, especially now, has been left rather untested, and we know little of how one could connect a cloned organ to a cloned vessel, be it, the body. The human body's various systems hold such complexity that to undertake such research would be not only vastly unethical, but also would be the most difficult of sciences. If, when cloning the body, one also cloned the brain, and it managed to develop correctly along with the rest of the cloned being, and if the computer stated above did exist, one could, once again in theory, get the impression of being immortal. Though, as I said, true immortality, being the infinite lifespan of a constantly living creature, is impossible by any real means.

This calls to mind another question. Would it be the same person? Would they have the same perspective? Conscience is not something one can transfer; it is more than a series of thoughts, it is a preternatural process. We know nothing of how ones existence is formed; it delves to deep into speculation and philosophy, and it rather depressing, at that!
(Everyone you know and love, and everything you think, is just the result of chemical reactions within your body and their bodies; meaning nothing between two humans has any real meaning or cognition save for those your own chemical reactions interpret, which calls to mind whether anything can be proven as real or true, if you are relying on chemical reactions which you have no control over and no knowledge of. I often ponder this and get rather morose. Don't let it get you down though, haha, life is what you make it.)

Back on topic;
Yes, cancer has been around for many years, though it has picked up drastically in the past hundred years. If life span were the issue, we would not also be seeing an increase of childhood cancers, and yet, we are. Along these same lines are the autism statistics, as well as almost any disease they consider "Inherited" when they should be labeled "Degenerated".
(Actually: History of Cancer )

Beyond that, as I said, this is the first generation that is expected to have a shorter lifespan than its predecessor. This is rather disconcerting considering the previous trend of lifespan; that with an upward slope.

And I sure hope death is never cheated; overpopulation is already an issue. Scientists have long-claimed that the world can only indefinitely support 500 million people. Currently, we are around 7 Billion. If we suddenly decided we could live forever, ironically, we would all be doomed.

This also calls to mind evolution; if humans are so self-absorbed as to think we are the end-all-be-all of life on Earth, they are crazy. Life in one million years will be as different as going back one million years. Humans will be long gone, in favor of some higher-developed life-form. Humans at this rate will never last as long, anyway, leaving room for other creatures to evolve to their potential without man's interference. So if one man were to find a way to be immortal, he would be a lone-man among a swarm of lower life for a long-while, until they developed into what humans once were, and beyond. The man would be left, undeveloped, and would live a rather sad existence alone. Speaking his English or French to ears which were not meant to hear such mumblings and gibberish.

I'm afraid I am enjoying writing about this a bit too much!