My sister had cancer and we did ignore the warning signs because the symptoms didn’t seem like anything concerning. As there are numerous types of cancers, most of them don’t have severe symptoms so people won’t think it’s all that serious. For instance, being simply fatigue could be a warning sign, along with night sweats. Loss of appetite, or even a sore that doesn’t heal. The warning signs are things most people will brush off and say “oh it’s probably just this or that”. That’s why whenever people go to the doctor and get diagnosed with cancer, it catches you by surprise.