The Food and Drug Administration (FDA) has expanded its approval of a noninvasive at-home colorectal screening test to include a younger portion of the population.

Cologuard, which identifies altered DNA or blood in stool, was initially approved in 2014 for people between 50 and 75 years old. Now, the test is available for individuals as young as 45 with a prescription from their doctor.

According to the American Cancer Society (ACS), rates of colorectal cancer in adults under age 55 have increased annually from 2006 to 2015. Last year, the ACS updated its screening guidelines to include individuals with average risk of colon cancer 45 to 49 years old.

“I think it is great to expand screening to the younger population, however keep in mind the screening tests for this type of cancer are ranked in three tiers based on performance features, cost and practical considerations,” said Dr. Luis Pena, a gastroenterologist in Moffitt Cancer Center’s Gastrointestinal Oncology Program. “A colonoscopy and fecal immunochemical test (FIT) are tier one, while Cologuard is tier two.” That means while Cologuard is an appropriate screening test, it has more disadvantages than tier-one tests.

The FIT is done once a year and uses antibodies to detect blood in the stool. For this test, you receive a test kit from your health care provider to perform at home. You use a brush to obtain a small amount of stool and return the test kit to the doctor or lab, where the samples are checked for the presence of blood.

Cologuard is considered a FIT-DNA test, or stool DNA test. For this test, you collect an entire bowel movement and send it to a lab where it is checked for cancer cells. It is done every three years.

Pena says while it is unlikely Cologuard would replace FIT in large organized screening programs, it could be particularly appropriate for patients in the 50 to 65 year age group who seek a noninvasive test with very high sensitivity for cancer because the test has better specificity in this age group.

Studies done at Moffitt show that about 6% to 10% of patients who utilize at-home colon cancer test kits have shown abnormal results. All abnormal test results must be followed up by a colonoscopy.