NAC is a glutathione precursor. It is both anti- and pro- cancer. It is anti-cancer in a sense that glutathione reduces the risk of getting cancer in the first place. It is pro-cancer in a sense that it reduces the power of immune response due to reduction of the amount of produced ROS, which may theoretically lead to a faster cancer spread.
So yeah, they both are kind of similar in that dimension.
I can't speak either way on the cancer effects, but fun fact to all reading, NAC is a great glutamate mop because glutathione is made of 3 amino acids, IIRC, and glutamate is one of them. NAC is literally just glutathione without the glutamate, and it crosses the BBB and such more easily too, I believe?
In any case, it grabs onto free glutamate, and, whammo! less glutamate, instant glutathione. quite the nifty trick.
has some interesting data/studies backing it up, and also has some great psychiatric effects as well. IIRC it's used for schizophrenia among other things.
So yeah, they both are kind of similar in that dimension.