Bad News that I receieved

I had tons of bad news that I had received, but, this new is the worst news I have ever receive. It was when my mother said that my Great Grand Father died two years ago. I cried a lot because my Great Grandfather was the dearest person to me beside my parents... I miss him a lot. He died because he had cancer, I'm not sure what kind of cancer it was because I forgot but my mom told me that when he had cancer, he suffered in pain, so I am very scare if any of my family or my friends will have it... I hope they won't.