The report below was published earlier this month in a well known tabloid (which gets grudging respect for acurately breaking numerous major stories, including the John Edwards affair with Reille Hunter and Bristol Palin's pregnancy during the 2008 Presidential campaign). It outlines in detail the seriousness of Williams health issues, stating that after rounds of radiation treatments and chemotherapy, his bladder cancer not only returned but metastasized. It also states he has lost significant weight and his hair.
On the positive side, it also states his ex wife Claudine Longet is with him in Branson, along with his present wife Debbie and children Noelle, Christian and Bobby.
http://www.nationalenquirer.com/celebrity/andy-williams-sad-last-days