Colorectal cancer develops quietly, often without early warning signs. It occurs in the colon or rectum and is the second leading cause of cancer-related deaths worldwide. Individuals with a family history of colorectal cancer face significantly higher risks due to genetic factors, which makes early detection through screenings and genetic testing especially important.
This article offers an overview of essential lab tests for individuals with a family history of colorectal cancer and explains how genetic makeup influences risk. By understanding these tests, individuals can collaborate with their healthcare provider to make informed decisions about colorectal cancer screening.
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Understanding Family History and Colorectal Cancer Risk
A person's family history can influence colorectal cancer risk. Understanding your family history and its impact on your health can be very useful when assessing your risk of colon cancer.
Impact of Family History on Colorectal Cancer Risk
A family history of colorectal cancer can increase an individual's risk of developing the disease due to shared genetic factors and lifestyle habits within families. Having a first-degree relative with colorectal cancer increases an individual's risk of the disease by 2 to 3 times.
Genetic mutations associated with familial colorectal cancer, such as Lynch syndrome and Familial Adenomatous Polyposis (FAP), play a significant role in this increased risk. Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer (HNPCC), raises the risk for various cancers. FAP leads to numerous polyps in the colon and rectum, which can become cancerous if untreated.
Given this increased risk, individuals with a family history of colorectal cancer may require earlier or more frequent screening.
Who Should Be Tested?
Most individuals should start screening for colorectal cancer shortly after turning 45 and continue at regular intervals. However, some may need to begin testing earlier than 45 or undergo more frequent screenings if they have:
- Inflammatory bowel disease, such as Crohn's disease or ulcerative colitis.
- A personal or family history of colorectal cancer or polyps.
- A first-degree relative diagnosed before age 50 or two or more first-degree or second-degree relatives diagnosed at any age.
- A genetic syndrome like Familial Adenomatous Polyposis (FAP) or Lynch syndrome.
Personalized risk assessments evaluate an individual's risk by examining family history, conducting genetic testing for mutations, and reviewing medical history. Lifestyle factors such as diet, physical activity, smoking, and alcohol use are also considered.
Newest Guidelines from Major Health Organizations
- The American Cancer Society (ACS) recommends starting regular screening for colorectal cancer at age 45 for average-risk individuals, while high-risk individuals may need to begin screening before this age.
- National Comprehensive Cancer Network (NCCN) provides specific guidelines for high-risk groups, including recommendations for genetic testing and screening intervals.
- U.S. Preventive Services Task Force (USPSTF) recommends screening for colorectal cancer in adults aged 45 to 75.
Lab Tests for Patients with a Family History of Colorectal Cancer
It is important to understand what lab tests are available for individuals with a family history of colorectal cancer, as they can help with early detection and monitoring. These include:
Fecal Occult Blood Test (FOBT)
FOBT is a simple screening tool used to detect hidden blood in the stool, which can be an early sign of colorectal cancer or polyps. This test indicates whether blood is present, but it cannot identify the source of the bleeding.
Performed annually, FOBT is recommended for individuals with average risk and no symptoms. FOBT may require dietary and medication restrictions, as these can sometimes result in false positives.
Fecal Immunochemical Test (FIT)
FIT is a screening option that offers advantages over FOBT. It specifically detects human blood in the lower gastrointestinal tract, making it a more accurate option for colorectal cancer screening.
FIT uses antibodies to detect human blood, requires no dietary changes, and is more accurate. It is performed annually and is often preferred for its ease of use and reliability.
Multitarget Stool DNA Test (Cologuard)
The Multitarget Stool DNA Test, commonly known as Cologuard, combines stool DNA analysis with blood detection. This test is particularly beneficial for patients with a family history of colorectal cancer, as it can identify both cancer and precancerous polyps.
One key advantage of Cologuard is that it can be completed at home. It also allows for early cancer detection at more treatable stages and is a less invasive alternative to colonoscopy.
Carcinoembryonic Antigen (CEA) Test
The Carcinoembryonic Antigen (CEA) test measures levels of CEA, a protein that may be elevated in certain cancers, particularly colorectal cancer. It is primarily used to monitor patients after treatment for colorectal cancer, helping to detect recurrence.
The CEA test is recommended for high-risk patients, especially those with a history of colorectal cancer. It typically begins 3 to 6 months after treatment, with testing every few months for the first couple of years, then less frequently based on risk factors. It may also be included in monitoring for patients with genetic conditions like Lynch syndrome FAP.
Genetic Testing for Hereditary Syndromes (Lynch Syndrome, FAP)
Genetic mutations like MLH1 and MSH2 are linked to hereditary cancer syndromes such as Lynch syndrome and FAP, which raise the risk of colorectal and other cancers. Families with these mutations often have multiple members diagnosed with cancer at a younger age, indicating a genetic predisposition that can be passed down. Testing family members identifies those who may carry cancer-related genetic mutations.
Colonoscopy
Colonoscopy is considered the gold standard for colorectal cancer screening. It allows for a comprehensive visual examination of the colon and the ability to biopsy polyps. High-risk individuals, such as those with a family history or specific genetic conditions, may need more frequent screenings every 1 to 3 years, starting before age 45.
Integrating Lab Tests into a Comprehensive Screening Plan
For individuals with a family history of colorectal cancer, lab tests are essential tools for assessing risk and guiding care.
Building a Personalized Screening Protocol
Healthcare providers can customize lab tests based on a patient's unique risk factors, including their personal and family medical history. This approach ensures that screenings are relevant and effective. They can choose from non-invasive options, such as blood or stool DNA tests, fecal immunochemical tests, and invasive procedures like colonoscopies for the best outcomes.
A blood or stool DNA test is a screening tool that detects cancer after it has developed, so it isn't used for prevention. In contrast, a colonoscopy can both screen for colon cancer before symptoms appear and remove polyps to prevent cancer from developing.
Regular follow-up testing is also important, as healthcare providers may recommend ongoing lab tests to monitor any changes after initial screenings.
Interpreting Test Results
Lab test results can range from normal to abnormal, even in high-risk patients. A normal result usually means no immediate concerns, but ongoing monitoring is still important, especially with a strong family history. An abnormal result may suggest polyps or cancer, requiring further evaluation.
It is essential to have a clear action plan for positive or unclear test results. This often includes follow-up procedures, like a colonoscopy, to investigate further and potentially remove polyps or take biopsies. Healthcare providers need to explain these results to patients and discuss lifestyle changes or preventive measures.
If results indicate a higher risk for hereditary colorectal cancer, patients may be referred to a genetic counselor for risk assessment and genetic testing. Collaborating with specialists ensures thorough evaluations and personalized care plans.
Addressing Gaps and Common Concerns
Patients with a family history of colorectal cancer often have specific concerns regarding their health screenings.
Common Questions from Patients with a Family History of Colorectal Cancer
Patients typically have questions related to testing: frequency of testing, the accuracy of the various screening and testing options, and the cost of this preventive care.
Frequency of Tests
One common question is the frequency with which high-risk individuals should be screened. Healthcare providers generally recommend more frequent screenings for those with a family history, often starting at an earlier age than the general population. This recommendation varies based on individual factors, including family history and genetics, so discussing this thoroughly with a healthcare provider is important.
Concerns About Test Accuracy
Patients frequently express concerns about the accuracy and reliability of different lab tests. As outlined above, it’s important for them to understand each test's strengths and limitations, as well as how results are interpreted.
Financial Considerations
Many also have financial concerns. Patients often want to know about insurance coverage and the costs associated with genetic and stool-based tests.
The Affordable Care Act (ACA) requires private insurers and Medicare to cover colorectal cancer screening tests recommended by the USPSTF. In most cases, there should be no out-of-pocket costs for these tests; however, it is advised to check with one’s health insurance plan.
Potential Barriers to Early Detection
Despite the importance of early detection, high-risk patients may encounter several obstacles. Accessing lab tests can be difficult due to logistical issues or limited availability, and many individuals may feel hesitant about invasive procedures like colonoscopies. Addressing these fears and offering support can encourage patients to pursue necessary screenings.
Honest discussions with healthcare providers are essential. The American Cancer Society provides a list of common questions to help patients gather the information they need for informed decisions about their care.
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Key Takeaways
- Early and personalized screening for patients with a family history of colorectal cancer is important for identifying risks and supporting preventive measures.
- Patient participation in risk assessment and lab testing is essential for early detection and personalized care.
- Healthcare providers must prioritize comprehensive testing for high-risk individuals and encourage open discussions about screening and genetic testing options to promote better health outcomes.
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