I do have a history of colon cancer in my family. Several years a I had a Colonoscopy (CO) and had 4 polyps of various sizes. All turned out to be the kind that do grow into cancer. they had a name adonomous or something like that.they were removed during the CO.
two years later I repeated the test and had none. now 3 years later I will get another CO. from my understanding the precancerous ones take a long time to turn into cancer. The others are not a problem.