Two years ago I watched my best friend die from cancer. It was awful.
Yes, pregnancies can be hard, but people need to remember that going through chemo is effectively having poisons pumped directly into your blood stream, and they affect everything! There is not only sickness to deal with, there is also chemo rash where itchy little blisters filled with what feels like acid form and burst, there is confusion, weight loss, muscle loss, diarrhea, exhaustion to the point of collapse, not to mention susceptibility to every little germ out there where contraction can be very serious, very quickly, and I'm talking about blue light ambulance journey to try to save a life. And that was just from the chemo, not from the cancer, the cancer brings it's own problems to the game.
People can choose to have children, no one chooses to have cancer.