My wife had some warning signs nearly a year ago, and we did nothing. To make a long story short, all hell broke lose when she started getting bleeding bowels. Please don't wait for symptoms, her oncologist said that colon cancer is the sneakiest form, and can hit you with little warning. There's more cases popping up of younger people getting it.
Don't wait. Don't let good overall good health fool you. Everybody feels pretty good at Stage 1 cancer...
Redundancy is bad, mkay?