Hi there... ditto what everyone else said. Just because they removed it surgically... even if there is no show on a scan, does not mean there is no cancer present. Cancer is cellular. There may be only a few cancer cells present and it will not show up on a scan but it could very well grow into a tumor and spread and then you are faced with a recurrence. best to have treatment full on to make sure he is clean. take care and welcome. and kids are like that. It scares them to face the possibility. I would give my kids regular updates. and never say... this will never come back. I say hopefully it won't so they are aware that there are no guarantees with this disease. hugs.