The drug he's on - Stivarga (regorafenib) - is nasty. Serious side effects / toxicity, including potential for sever liver damage. It can also basically blow holes in the intestinal tract. They don't mention what he's being treated for, but I suspect - and this is pure conjecture - it's GIST (gastrointestinal stromal tumor). Stivarga is an inhibitor of two key enzymes (a "dual kinase inhibitor") that's usually used after a patient has failed several other drugs (single kinase inhibitors that are frankly less toxic). Many of these patients unfortunately may have worked their way through the other drugs in the armament and recurrences late in the game may be unresectable (surgery's not really an option anymore). He deserves tremendous credit for keeping so active and remaining "positive" for his daughters (and himself).
