How come so often, someone beats cancer the first time and then it comes back and kills them? i am sure these people are getting more routine screening and looking out for reoccurrence, so how does it get to the point of losing the battle?

Unfortunately, sometimes there are microscopic cancer cells in places that cannot be seen in the typical scans. Then, when these microscopic cells grow, the cancer returns and it is sometimes widely metastatic-meaning the cancer.is now in multiple places in the body. This makes any treatment palliative-meaning it gives the person more time but it does not cure them. Good luck!