Peds cancer is tragic. Often times atherosclerosis and heart disease is exacerbated by lifestyle choices.
Many times people just die. This man gets to have that problem fixed and doesn't have to deal with having a cardiac event, potentially dying, going through resus in a hospital as his family wonders if he will live, staying in the ICU etc.
Surgery is never fun but the circumstances of this are grossly different than pediatric cancer. So in the terms of peds caner I agree with you. I would never be grateful for that. It would be horrific to watch my flesh and blood fight through that and not knowing if they would live.