Risk factors and screening techniques in 500 patients with benign and malignant colon polyps. An urban community experience.

The authors have reviewed 13 years of experience with 500 patients who had 1240 polypoid lesions identified at colonoscopy. An analysis of these patients' symptoms, signs, and past histories prior to initial colonoscopy were collated by computer in order to provide useful information to help in early identification of patients with polyps and to define specific risk factors in patients with polypoid cancers (71 patients with 79 cancers). This study shows that the 500 patients with colon polyps, with and without cancer, are similar in all parameters measured. Their symptoms correlated poorly with the pathology or location of the polyp. Frequently unrelated symptoms brought the patient to the attention of their private physician. A significant high-risk group of patients identified were those with prior colon polyps and cancer. A positive family history of colon cancer was not common. Barium enema, the most common examination, was performed in 90 percent of patients and was the first test to diagnose polyps in 54 percent. Flexible sigmoidoscopy, only more recently available and performed in 20 percent of the patients, established a diagnosis of polypoid disease 96 percent of the time. This study supports screening for all adults above 40 years of age with flexible sigmoidoscopy and stool occult blood.

Review of recurrent polyps and cancer in 500 patients with initial colonoscopy for polyps.

Five hundred patients with 1240 polyps removed by colonoscopy and polypectomy over a 13-year period are the subject of ongoing follow-up study. Ninety-three percent of the patients have been followed an average of 53 months with a recurrence rate of polypoid disease in 26 percent, of which approximately 7 percent demonstrated malignant changes. This compares to a rate of 7 percent metachronous cancer in patients with a malignancy demonstrated at any time in the past. The highest risk group for recurrence are patients with more than four polyps at initial colonoscopy, with a 59 percent recurrence rate. The following recommendations for follow-up are made: 1) Flexible sigmoidoscopy is adequate yearly follow-up if the original polyps are confined to the rectum and sigmoid. 2) Colonoscopy should be carried out the first year if the original polyps are beyond the rectum and sigmoid, and yearly until the colon is cleared of recurring lesions. 3) Colonoscopy is indicated in patients with cancer before surgery if possible; if not, within six months after resection. 4) Interval six-month examinations are indicated in patients with colon cancer and multiple synchronous polyps until the colon is cleared. 5) Large, sessile polyps resected piecemeal require a three-month follow-up until gone. 6) When the above conditions are met, colonoscopy at three-year intervals is adequate for long-term follow-up of neoplastic polyps to detect and prevent early malignancy.