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Start screenings at age 45 to prevent colorectal cancer, UT Southwestern experts advise

Illustration of colorectal polyps, showing numerous polypous protrusions on the the lining of the intestine.
An illustration shows polyps on the lining of the colon, or large intestine. The structure of small polyps changes over time, and they can become cancerous, a process that takes about 10 years. (Photo credit: Getty Images)

DALLAS – June 06, 2023 – Colorectal cancer is on the rise among younger adults. According to the American Cancer Society, the proportion of cases among people under 55 increased from 11% in 1995 to 20% in 2019, and it is now the leading cause of cancer-related deaths for men younger than 50.

But colorectal cancer, which affects the large intestine (colon) or the rectum, is preventable if precancerous polyps are removed before they become malignant. Screening for the cancer – now recommended starting at age 45 by the U.S. Preventive Services Task Force – is crucial, said Rozina Mithani, M.D., Associate Professor of Internal Medicine, and Agnes Augustine, M.S.N., APRN, AGNP-C, both members of the Division of Digestive and Liver Diseases at UT Southwestern Medical Center.

Rozina Mithani, M.D.
Rozina Mithani, M.D., is an Associate Professor of Internal Medicine in the Division of Digestive and Liver Diseases at UT Southwestern.

“Early detection and intervention can lead to better outcomes in all cases,” said Dr. Mithani.

Men are somewhat more likely to develop polyps than women, both experts said. They advised that people should start screening for colon cancer earlier than age 45 if they have a family history of cancer or colon polyps. If an immediate family member has had colon cancer, talk to your health care provider, particularly if the cancer developed at an early age.

Colonoscopy is the most common and accurate type of screening for colorectal cancer, but any screening is better than none with this preventable cancer, Dr. Mithani and Ms. Augustine said. The test allows a physician to see directly inside the entire colon and, if needed, to remove any polyps and send them to a lab for biopsy. A colonoscopy finds most small polyps and almost all large polyps and cancers.

If there’s a positive result from another screening test, such as CT colonography (CTC), stool test for blood or DNA, or sigmoidoscopy, you’ll also need a colonoscopy. But if you have a colonoscopy first, another test probably won’t be necessary.

Agnes Augustine, M.S.N., APRN, AGNP-C
Agnes Augustine, M.S.N., APRN, AGNP-C, is a member of the Division of Digestive and Liver Diseases at UTSW.

Although colorectal cancer might not cause symptoms at first, patients can develop stomach pain, changes in bowel movements (number, texture, color, size), bloody stool, and weakness, fatigue, or shortness of breath.

Over time, the structure of small polyps changes, and they can become cancerous, a process that takes about 10 years.

Colon polyps are common in men and women of all races in industrialized countries, suggesting dietary and environmental factors play a role in their development, Dr. Mithani and Ms. Augustine said. Lifestyle risk factors include a high-fat diet, a diet high in red meat, a low-fiber diet, obesity, and smoking.

Some types of precancerous polyps (adenomas) have the potential to become cancerous, while others (hyperplastic or inflammatory polyps) have virtually no chance of becoming cancerous.

Genetics plays an important role in familial and hereditary colon cancers, both UT Southwestern experts said. Some rare genetic diseases increase the chance of getting colorectal cancer relatively early in adulthood, including familial adenomatous polyposis and MUTYH-associated polyposis, a gene mutation that can cause multiple colon polyps. Lynch syndrome, also known as hereditary nonpolyposis colon cancer, increases the risk of polyps and cancer.

Testing for these genes may be recommended for families with high rates of cancer. People diagnosed with colorectal cancer should have genetic testing, which may identify the presence of some of these conditions.

About UT Southwestern Medical Center
UT Southwestern, one of the nation’s premier academic medical centers, integrates pioneering biomedical research with exceptional clinical care and education. The institution’s faculty has received six Nobel Prizes, and includes 26 members of the National Academy of Sciences, 19 members of the National Academy of Medicine, and 14 Howard Hughes Medical Institute Investigators. The full-time faculty of more than 2,900 is responsible for groundbreaking medical advances and is committed to translating science-driven research quickly to new clinical treatments. UT Southwestern physicians provide care in more than 80 specialties to more than 100,000 hospitalized patients, more than 360,000 emergency room cases, and oversee nearly 4 million outpatient visits a year.