I know someone that has primary cancer in his stomach (gist) and was taking gleevec for chemo. He recently found out the chemo didn't work and he has a problem in the past with meth. Could it be because he used that the chemo didn't work?

He will need to discuss this with his oncologist. Most likely the past meth use has little to do with whether the chemo worked, but we cannot state that for certain.

Most likely the past meth use has little to do with whether or not the chemo worked, but we cannot state that for certain.

Reiterating the foregoing by J_9 Possible but very unlikely

Reiterating the foregoing by J_9 Possible but very unlikely

Explain please.