5-Minute Test Cuts Colon Cancer Risk

An easy test, with few or no complications or secondary effects, taken once in a lifetime, may lower mortality of colon cancer by 43% and incidence by over 30%, according to a new study published this month in The Lancet.

Colon cancer is the 5th most common cancer, after melanoma, prostate cancer (for men), breast cancer (for women), and lung cancer. The lifetime risk of being diagnosed with colon cancer for men and women is over 5%. Developments that significantly lower colon cancer risk and/or mortality have a significant impact to average life expectancy for all of us.

This UK study followed more than 170,000 subjects between the age of 55 and 64, and compared those who had undergone sigmoidoscopy with a control group of subjects who had not been screened. After a follow-up of 11 years, the screened subjects were 31% less likely to have been diagnosed with colon cancer, and 43% less likely to have died of it. There was no sign of the effect wearing off either, possibly because most or all cancer precursor polyps may already be in place and detectable at age 55.

Sigmoidoscopy is a simple procedure, significantly less impacting than colonoscopy, simpler and less risky, as well as less costly. It requires no anesthesia and can be performed by nurses. The nurse inserts a thin tube with a small camera (flexi-scope) through the rectum to inspect the lower bowel, which is the location for half of all colon cancers. The nurse then snips polyps, which can be cancer precursors, with a cutting tool inserted through the same tube. Cancers issued from higher up in the bowels may be detected through a fecal occult blood test.

Harpal Kumar, head of Cancer Research UK, the UK equivalent of the American Cancer Society, calls this study a breakthrough: "We don't often use the word ‘breakthrough,' but this is one of those rare occasions when I am going to use that word... It is extremely rare to see the results of a clinical trial which are quite as compelling as this one." The study suggests a detection protocol consisting of the combination of a single sigmoidoscopy at age 55 along with regular fecal occult blood tests.

Dr. Durado Brooks, director of prostate and colorectal cancer at the American Cancer Society, said that the study results confirm the value of its colon cancer screening guidelines and would not change them. The American Cancer Society's guidelines include (but are not limited to) sigmoidoscopies every 5 years, and, alternatively, colonoscopies every 10 years.

Interested in reading more about this? Find more information in the Washington Post, WebMD, MedPage Today,  Bloomberg Business Week,  Reuters, BBC News (UK), or the LA Times.

Lifetime probability of developing cancer or dying from it  (American Cancer Society)