Comment by LorenPechtel

And note that it's not "get cancer" but "find cancer".

In a harsh environment how many die of a tumor that saps their energy before causing any specific effect that causes them to seek out a doctor and presents with something the doctor can find without the million-dollar machinery?

Let's grab our Mr. Fusion and head back a quarter century. My father came to visit. He had definitely declined since the last time we saw him but had no known major health issues. There wasn't anything in particular, yet what my wife saw was enough that she said we wouldn't see him again. Half a year later the big machines found the cancer. Would he have made it that half year in a harsh environment? No.