“Colonoscopies can reduce colorectal cancer risk by 40%”

Colorectal cancer is the third most common cancer diagnosed in both men and women in the United States. According to the American Cancer Society, there were 95,520 cases of colon cancer and 39,910 cases of rectal cancer in 2017.

The CDC generally recommends colonoscopies starting at age 50, but earlier for people at increased risk, including those with a history of colorectal polyps or other bowel issues. According to a Harvard School of Public Health study published by the New England Journal of Medicine, colonoscopies can help reduce colorectal cancer risk by 40%.

Sigmoidoscopies, which only scope the left colon (sigmoid and descending colons), can only screen for distal colon cancers, but not right and upper colon cancers. In the right colon, there are flat adenomas, which are harder to see. The Harvard study showed that both colonoscopy and sigmoidoscopy were associated with a reduced incidence of cancer in the distal colorectum, but only colonoscopies were linked to reduced incidence of cancer that begins in the proximal colon and, most importantly, to reduced mortality from this type of cancer.

The adenoma detection rate (ADR) is the proportion of individuals undergoing a screening colonoscopy who have one or more adenomas detected. The current national benchmark for ADR is 25% (30% in men and 20% in women). SJGI conducted a 2017 colonoscopy study to see whether our physicians’ ADR is on par with the national benchmark and found that we surpassed all benchmarks for quality at 45% (50% in men and 40% in women). Among 6,200 colonoscopies done last year by SJGI, 48 patients had colon cancer. The rate of colon cancer in our patient population is 8 per 1,000.