Success Rate of Non-Invasive Colon Cancer Test Questioned


It appeared there was a new, easy way to screen for colon cancer in 2014. The Cologuard procedure promised a simple, less invasive and no-fuss screening of the disease with results in two days. But a recent Harvard Health Publication article says the test’s nearly 95 percent success rate might be flawed — the major study done on the screener was conducted by the company that manufactures the product.

In the original study, Cologuard identified 92 percent of colorectal cancers and 42 percent of advanced polyps. The study compared that success rate to the fecal immunochemical test (FIT), the only other non-invasive option, which identified 74 percent of cancers and 24 percent of advanced polyps.

The Potential Conflict of Interest

The review by Harvard Health found that Exact Sciences, the creator of Cologuard, was behind the only major study that supplied the data on the recommendations. A second smaller study done on Cologuard, which showed similar supporting results, was authored by the co-inventors of Cologuard technology and the scientific advisors to Exact Sciences. Because of this, the Harvard report recommends that any negative Cologuard result should be followed up with additional testing or screening via colonoscopy.

It’s important to note that the doctor who authored the Harvard Health report says she would still recommend Cologuard to her patients, but she would encourage them to take the research with a “big grain of salt.”

Related: Research Reveals How Indian Long Pepper Works to Fight Cancer

How Cologuard Works

The patient is mailed a stool collection kit. After the patient sends the sample back, the company runs the test, and numerical results are run through a special equation that tests for positive or negative results. The results are sent to the patient’s doctor, who then reports the findings to the patient. A positive test means the patient must be evaluated further via colonoscopy to locate the polyp or cancer.

The Prevalence of Colorectal Cancer in the U.S.

The fourth most common cancer in the United States, colorectal cancer is the second leading cause of cancer death, according to government statistics. Over a million people are currently living with the diagnosis, and 134,000 new cases are expected this year. Nearly four percent of all adults will be diagnosed with colorectal cancer in their lifetime.

The risks of acquiring the disease increase when you have a first-degree relative with colorectal cancer or precancerous polyps, or if you have a personal history of polyps. Obesity, alcohol use and smoking can also increase a person’s risk. African Americans have the highest risk out of all racial groups.

Cancers of the colon and rectum are very common, but with early detection there is a 90 percent survival rate, that is if the cancer is caught before it spreads.

Related: Balancing Gut Bacteria Could Be the Key to Solving Chronic Stomach Problems

Ronke Idowu Reeves

Ronke Idowu Reeves is a writer and journalist who hails from Brooklyn, NY. Her news and entertainment stories have appeared on WABC-TV-New York, Fox News Channel, VH1, plus in Sundance Film Festival’s Sundance Daily Insider and People Magazine.