Wolff and Shinya's colonoscopic polypectomy

Polyps of the colon can turn malignant. Before 1969, those out of reach of the rigid sigmoidoscope had to be watched with repeated barium enemas or removed by opening the abdomen and the colon. Flexible fiberoptic instruments were beginning to change that: Overholt reported his first examinations of the colon with a flexible scope in 1967, and in Japan clinicians were designing colon fiberscopes with the makers Machida and Olympus.

At Beth Israel Medical Center in New York, W. I. Wolff and Hiromi Shinya began colonoscopy in 1969, using an instrument developed in Tokyo by Niwa and Yamagata. Shinya added a wire-loop snare, pushed through a channel of the colonoscope, that could cut and cauterize a polyp as soon as it was seen, so no second procedure was needed. Between June 1969 and June 1972 they performed more than 1,600 diagnostic colonoscopies. In February 1973 they described polypectomy through the fiberoptic colonoscope in the New England Journal of Medicine, for neoplasms beyond the reach of the sigmoidoscope.

Shinya, who also worked at Mount Sinai, kept at it. By 1982 he reported about 45,000 colonoscopies and more than 10,000 polypectomies of lesions larger than 0.5 cm. Removing polyps was the first therapeutic use of the colonoscope, which later took on the treatment of bleeding, strictures, perforations and foreign bodies.

Whether polypectomy actually prevented cancer took longer to show. The National Polyp Study followed 1,418 patients who had had one or more adenomas removed at a complete colonoscopy, for an average of 5.9 years. Colonoscopy found five early cancers, all without symptoms, and no symptomatic cancers appeared. Measured against three reference groups, colorectal cancer incidence was 76, 88 and 90 percent lower than expected. The results were published in the New England Journal of Medicine in 1993.