Medical professionals often call cancer "the silent killer." And there are good reasons why. Because most cancer signs and symptoms don’t show up until it’s too late to do anything about it. So, when it comes to cancer, don’t rest on your laurels. And just in case, here are some possible cancer signs that might help you stop its progression before it’s too late. A lot of these symptoms could indicate something much less serious. So always check with your doctor if you're concerned.