I'm not saying it would mean end of life

Two things

What allows increased life span things like telemore extensions, cellular repair also increase often cancer risks, essentially what often limits cellular repair, regeneration often limits cancer

We all have latent cancer but sometimes something us kills us first. Mice get cancer in such high rates in old age because essentially natural selection in the wild made it so most didn't live past a certain time, so cancer in old mouse age wasn't selected against, again with humans, extreme old age will mean certain cancers might show up at 130 that we wouldn't see without