Bad news for my brother.

The Mayo Clinic in FL. where he lives has just told him that the cancer is
so aggressive that there isn't anything else they can do for him.

He is getting a second opinion from MD Anderson Cancer Center in Houston. I just found out that the type of cancer he has spreads through the body 70% of the time.

It's possible that he might be among that percentage.
He had a PET Scan yesterday that was concerning. That was followed up by an MRI. There seems to be "elevated metastatic activity." It's unclear whether that's from the amputation area trying to heal or from the cancer returning.