Dont take the anti cancer drug so liberally. Your grandpa's situationi is very similar to my Grandma, whose lung problem was later shown to be the accumulation of her "tan", which she can not expel since she is too old and the muscles are too weak. I cant believe that the doctor allow your grandpa to have anticancer drugs when they could not find any cancer cells.

Better find a good doctor to do some examination again. Anti-cancer drugs are also cancer inducer in some way, dont just take it as Tylenol

引用我们常说的一句话。。所有的药都有毒性的。。能停就得快停。

not in the case of chemo drugs. if it ain't broken don't fix it.