Cancer affects most families in some form, be a family member or a friend.  The fear that is felt is comparable to this event.  The unknown and waiting for results is consumed with fear/the worst "what if" feelings.  

In my lifetime, I have had my family cancer memories and at a very young age, watched some friends lose their life or parent due to cancer.  This is for them..... high heights has always been my greatest fear, so conquering this activity is a way to celebrate their memories/lifetime.