I know Guy’s cancer isn’t contagious; you can’t catch it off him, no matter how close you are…

I know Guy&rsquo;s cancer isn&rsquo;t contagious; you can&rsquo;t catch it off him, no matter how close you are physically or genetically, not even if you&rsquo;re his son. That&rsquo;s the thing about cancer; it&rsquo;s all yours — it&rsquo;s entirely, perfectly personalised. The cause might have come from outside — carcinogens in tobacco smoke or whatever — but that just triggered the runaway…