My brother had mild breathing issues and back pain for a really long time. He resisted getting tested until the day his pain got severe enough to call for an am

My brother had mild breathing issues and back pain for a really long time. He resisted getting tested until the day his pain got severe enough to call for an ambulance. It turned out to be a giant tumor - large enough to press against nerves and cause back pain. He’s the fittest person I know and we all thought he overdid himself at the gym causing a back issue. It’s just that everything can be cancer and nothing. Some cancers have obvious symptoms others not so much. Any unexplained and rapid weight loss seems to be the most obvious. I don’t want to look up all the symptoms. Everything from gastric issues, back pains to moles and warts can be due to cancer.