Does telomere elongation in cloned organisms lead to a longer lifespan   if cancer is considered ?
  ... By additionally considering a two-mutation model for carcinogenesis and indefinite proliferation by the activation of telomerase, we demonstrate that the risk of dying doe to cancer can outweigh the positive effect of longer telomeres on the longevity. 
M. Masa, S. Cebrat and D. Stauffer