What I understand by “Life extension” can be 1/ the effective source or reason that allows someone to live for a substantially longer period of time. 
2/ history, the extension of someone in time though tales and stories. 

In my opinion 2 would be the most possible case to your argument. 

But not life, or essence of a being. That is too much day for such a ledger. 

PS: I don’t really know about quantum physics.