OP imo your family is half right. I believe firmly that they're things that can be done to drastically increase ones chance of cancer survival, at cost. Not in a "gubment holding out" miracle drug way, more like expensive frequent blood transfusions, intravenous liquid meals, constant therapy kind of way. If you can afford it, you'll hear about it, however there is no miracle cure for anyone.
That's the saddest part really, you always hear about miracle cures as if they exist and for sale only to the elite. This is so backwards it hurts. Reality is, prevention is the only cure at this stage, available to rich/poor/young/old, that's where the government is truly letting their people down. Allowing known cancer producing products that unquestionably kill to be sold and taxed puts dollars in coffers at human cost. Blood is definitely on their hands, OP's family is misguided but not far off.