Screening Sigmoidoscopy for Colorectal Cancer

Abstract

There is controversy about the value of screening for colorectal cancers. These cancers are thought to develop by progression through a series of premalignant and early malignant phases that culminate in invasive cancer. Theoretically, screening procedures that detect and lead to the removal of adenomatous polyps or early cancers should result in a decrease in mortality. Unfortunately, there is incomplete evidence to date from any prospective study that screening produces this benefit. The lack of evidence supporting the efficacy of screening for colorectal cancer has led to a divergence in expert recommendations. The National Cancer Institute, the American Cancer Society, . . .