You asked if the other poster was an oncologist, as though only oncologists have relevant opinions or thoughts about cancer. Your post completely dismissed the validity of the other poster's opinion. Oncologists are not the only people who can speak authoritatively about cancer.
You are full of crap. The other poster claimed to "know all about it." Something that someone who is an oncologist might validly make, but not someone who had a relative with it. And "knowing all about it" is not a claim I'd make. And no I'm not an oncologist, but one of my past jobs was analyzing data from clinical trials for cancer treatments, so I know a fair amount about life expectancies vs staging with and wihout treatment etc. but very little about the clinical side of it.