While advancing there is increased chance of developing cancers. Tumorigenesis in aging is due to:
Telomerase is a ribonucleoprotein that is expressed in stem cells and most cancer cells, but not in somatic cells. More than 90% of human cancers express high levels of telomerase that prevent telomere shoening to critical levels and allow indefinite cell proliferation. Ref: Longo D.L. (2012). Chapter 84. Cancer Cell Biology and Angiogenesis. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison's Principles of Internal Medicine, 18e.
Telomerase reactivation
Telomerase inactivation
Increased apoptosis
Suppression of proto-oncogenes