There is a theory that has substantial evidence that &quot;senescence&quot; the technical term for aging is a defense against cancers.  Here is a long article about how cancer and senescence are related.[0]<p>[0]<a href="http:&#x2F;&#x2F;www.nature.com&#x2F;nature&#x2F;journal&#x2F;v448&#x2F;n7155&#x2F;full&#x2F;nature05985.html" rel="nofollow">http:&#x2F;&#x2F;www.nature.com&#x2F;nature&#x2F;journal&#x2F;v448&#x2F;n7155&#x2F;full&#x2F;nature0...</a>