Colon Cancer Screening in Dallas & Sachse, TX

Why Colon Cancer Screening Matters

Colorectal cancer is the third most commonly diagnosed cancer and the second leading cause of cancer-related death in the United States, according to the American Cancer Society (ACS). In 2024 alone, an estimated 153,000 new cases of colorectal cancer were diagnosed and approximately 53,000 Americans died from the disease. Despite these sobering numbers, colorectal cancer is also one of the most preventable and treatable cancers when caught early through screening.

The goal of colon cancer screening is twofold: to detect cancer at an early stage, when treatment is most effective, and to find and remove precancerous growths called polyps before they have a chance to become cancerous. This is what makes colorectal cancer screening uniquely powerful compared to screening for many other types of cancer — it can actually prevent cancer, not just detect it.

Studies published in the New England Journal of Medicine and other leading medical journals have shown that regular screening with colonoscopy and polypectomy (polyp removal) can reduce the incidence of colorectal cancer by 40% to 90% and reduce colorectal cancer mortality by 29% to 68%. When colorectal cancer is found at an early, localized stage, the 5-year survival rate is approximately 91%. When diagnosed at a distant (metastatic) stage, the survival rate drops to approximately 14%.

At Texas Gut Health in Sachse, TX, Dr. Jaison John is dedicated to helping patients throughout the Dallas-Fort Worth area understand their screening options, assess their personal risk, and choose the right screening strategy. Dr. John completed his gastroenterology fellowship at UT Medical Branch, where he served as Chief Fellow, and his internal medicine residency at UT Austin Dell Medical School, where he served as Chief Resident. He holds dual board certifications from the American Board of Internal Medicine in both internal medicine and gastroenterology.

Current Screening Guidelines

Three major medical organizations provide guidelines for colorectal cancer screening in the United States. While they differ slightly in their specific recommendations, all agree on the critical importance of screening beginning at age 45 for average-risk adults.

American Cancer Society (ACS)

• Adults at average risk should begin regular screening at age 45.
• Screening should continue through age 75 for people in good health with a life expectancy of more than 10 years.
• For adults aged 76 to 85, the decision to screen should be individualized based on patient preferences, life expectancy, overall health, and prior screening history.
• Adults over 85 should no longer undergo screening.

U.S. Preventive Services Task Force (USPSTF)

• Recommends screening for all adults aged 45 to 75 (Grade A recommendation).
• For adults aged 76 to 85, the decision to screen should be individualized (Grade C recommendation). The net benefit is smaller in this age group and depends on individual risk factors and overall health.
• The USPSTF does not specify a preferred screening method but recognizes multiple effective options including colonoscopy, FIT, FIT-DNA, and CT colonography.

American College of Gastroenterology (ACG)

• Recommends colonoscopy as the preferred screening test for average-risk adults beginning at age 45, repeated every 10 years if normal.
• Recognizes annual FIT as the preferred alternative for patients who decline or cannot undergo colonoscopy.
• Recommends that African American patients consider beginning screening at age 45 (this recommendation predated the broader lowering of the screening age from 50 to 45 for all adults).
• Emphasizes that any positive stool-based test or CT colonography must be followed by a colonoscopy for definitive evaluation.

Screening Methods

Several evidence-based screening methods are available for colorectal cancer. Dr. John will help you determine which approach is most appropriate based on your age, risk factors, medical history, and personal preferences.

Colonoscopy (Every 10 Years)

Colonoscopy is the gold standard for colorectal cancer screening. It is the only screening method that both detects and prevents cancer in a single procedure by allowing the physician to find and remove polyps during the same exam. Colonoscopy examines the entire colon and rectum, and a normal result in an average-risk patient allows a 10-year interval before the next screening. Colonoscopy requires bowel preparation and intravenous sedation, and a responsible adult must be available to provide transportation home after the procedure.

Fecal Immunochemical Test — FIT (Annual)

FIT is a stool-based test that detects hidden blood in the stool, which can be an early sign of colorectal cancer or large polyps. FIT is non-invasive, inexpensive, and can be done at home using a kit provided by your physician. It does not require bowel preparation or dietary restrictions. However, FIT must be performed every year to be effective, and any positive result must be followed up with a colonoscopy. FIT does not detect most polyps and has lower sensitivity for early-stage cancer compared to colonoscopy.

Stool DNA Test — FIT-DNA / Cologuard (Every 3 Years)

The FIT-DNA test (marketed as Cologuard) combines a FIT test with a test for altered DNA markers shed by colorectal cancers and advanced polyps into the stool. It is more sensitive than FIT alone for detecting cancer and advanced adenomas but has a higher false-positive rate. The test is done at home using a collection kit. A positive result requires follow-up with a colonoscopy. The recommended interval for FIT-DNA is every 3 years.

CT Colonography — Virtual Colonoscopy (Every 5 Years)

CT colonography uses specialized CT scanning to produce detailed images of the colon and rectum. It requires bowel preparation similar to colonoscopy but does not require sedation. If polyps or suspicious findings are detected, a follow-up colonoscopy is required for biopsy or removal. CT colonography involves exposure to ionizing radiation and cannot be used to remove polyps or obtain biopsies.

Flexible Sigmoidoscopy (Every 5 to 10 Years)

Flexible sigmoidoscopy examines the lower third of the colon (the rectum and sigmoid colon). It does not evaluate the entire colon and is therefore less comprehensive than colonoscopy. Sigmoidoscopy may be combined with annual FIT for a more thorough screening approach. It requires only a limited bowel preparation and may or may not involve sedation.

Risk Factors for Colorectal Cancer

Understanding your personal risk factors for colorectal cancer is essential for determining when to start screening and how often to be tested. Risk factors fall into two categories: modifiable and non-modifiable.

Non-Modifiable Risk Factors

• Age: The risk of colorectal cancer increases significantly after age 45, with the majority of cases diagnosed in adults over 50.
• Family history: A first-degree relative (parent, sibling, or child) with colorectal cancer or advanced adenomatous polyps, especially if diagnosed before age 60, significantly increases your risk. The ACG recommends screening 10 years before the youngest affected relative's age of diagnosis, or at age 40, whichever comes first.
• Personal history of polyps or colorectal cancer: Patients with prior adenomatous polyps or a personal history of colorectal cancer are at increased risk for recurrence and require more frequent surveillance.
• Inflammatory bowel disease (IBD): Long-standing Crohn's disease or ulcerative colitis involving the colon increases colorectal cancer risk. Surveillance colonoscopy should begin 8 years after IBD diagnosis.
• Hereditary cancer syndromes: Lynch syndrome (hereditary nonpolyposis colorectal cancer) and familial adenomatous polyposis (FAP) carry very high lifetime risks of colorectal cancer and require early, intensive screening and surveillance.
• Race and ethnicity: African Americans have the highest incidence and mortality rates from colorectal cancer among all racial and ethnic groups in the United States.

Modifiable Risk Factors

• Physical inactivity: A sedentary lifestyle is associated with increased colorectal cancer risk. Regular physical activity has been shown to reduce risk by up to 24%.
• Obesity: Excess body weight, particularly abdominal obesity, is linked to an increased risk of colon cancer, especially in men.
• Diet: Diets high in red and processed meats and low in fruits, vegetables, and whole grains have been associated with higher colorectal cancer risk.
• Tobacco use: Long-term smoking increases the risk of developing and dying from colorectal cancer.
• Heavy alcohol consumption: Moderate to heavy alcohol intake (3 or more drinks per day) is associated with an increased risk of colorectal cancer.
• Type 2 diabetes: Individuals with type 2 diabetes have an increased risk of colorectal cancer, independent of obesity.

If you are a resident of Sachse, Murphy, Wylie, Plano, Garland, Rowlett, Richardson, or anywhere else in the Dallas-Fort Worth metroplex and are unsure about your risk level or when to start screening, Dr. John can help you develop a personalized screening plan.

Risks and Benefits of Screening

Benefits

• Cancer prevention: Colonoscopy screening with polypectomy can prevent up to 90% of colorectal cancers by removing precancerous polyps before they become malignant.
• Early detection saves lives: Colorectal cancer detected at an early, localized stage has a 91% five-year survival rate, compared to 14% when found at a distant stage.
• Multiple options available: Patients can choose from several evidence-based screening methods, including non-invasive stool-based tests, depending on their preferences and risk profile.
• Coverage under the ACA: Screening colonoscopy is covered at no out-of-pocket cost for eligible patients under most insurance plans, removing a major financial barrier.

Risks

The risks of screening depend on the method used:

• Colonoscopy risks: Serious complications from colonoscopy are uncommon. The overall complication rate is approximately 2.8 per 1,000 procedures. Risks include bleeding (approximately 1 in 1,000 with polypectomy), perforation (approximately 1 in 1,500 to 2,000), and adverse reactions to sedation. For a detailed discussion of colonoscopy risks and benefits, see our colonoscopy page.
• Stool-based test risks: FIT and FIT-DNA carry no physical risks. The primary risk is a false-positive result, which leads to an unnecessary follow-up colonoscopy, or a false-negative result, which may provide false reassurance.
• CT colonography risks: CT colonography involves exposure to ionizing radiation and may identify incidental findings outside the colon that require further workup, potentially causing anxiety and additional testing.

The unanimous consensus of the ACS, USPSTF, ACG, and AGA is that the benefits of colorectal cancer screening far outweigh the risks for adults ages 45 to 75.

Frequently Asked Questions