Lynch syndrome is an inherited genetic condition that greatly increases a person’s risk of developing colon cancer. While it is the #1 most common inherited cause of colorectal cancer, many people aren’t aware of the connection between the two. This blog will explain what Lynch syndrome is, how it disrupts DNA repair processes, and why it increases the risk of early-onset colon cancer.
What is Lynch Syndrome?
Lynch syndrome is characterized by mutations in specific genes responsible for repairing DNA errors in cells. These are known as mismatch repair (MMR) genes, and when they are mutated, they can no longer properly fix mistakes that occur during cell division.
Your cells replicate and divide as part of natural growth and repair. Sometimes, errors – known as mutations – occur in the DNA during this process. Fortunately, the MMR genes act as a sort of quality control, fixing these errors before they can cause problems. But when the MMR genes themselves are mutated due to Lynch syndrome, these errors accumulate over time, increasing the likelihood that cancer will develop in certain tissues, most notably in the colon.
READ MORE: What is Lynch Syndrome and How Can it Impact My Life?
The Role of Mismatch Repair Genes in Cancerous Tumor Formation
To understand why Lynch syndrome leads to cancer, it’s important to know what mismatch repair genes do. These genes, including MLH1, MSH2, MSH6, PMS2, and EPCAM, are responsible for detecting and correcting DNA errors. Without these repairs, cells begin to divide uncontrollably and can turn cancerous.
When one of these genes is mutated, it impairs the body’s ability to repair DNA mistakes. As a result, the accumulation of genetic errors can trigger the formation of tumors, particularly in the colon and other parts of the gastrointestinal tract. For individuals with Lynch syndrome, this process begins at a much earlier age than for those with sporadic (non-genetic) forms of colon cancer, making early detection and regular monitoring imperative.
Lynch Syndrome and Colon Cancer Risk
The link between Lynch syndrome and colon cancer is well-established. Those with Lynch syndrome have a significantly higher lifetime risk of developing colon cancer compared to the general population. In fact, it is estimated that individuals with Lynch syndrome have a lifetime risk of 50-80% for developing colon cancer. This is compared to around 4-5% of the general population.
As mentioned earlier, Lynch syndrome-associated colon cancers develop earlier than other types of colon cancers. People with Lynch syndrome often develop colon cancer somewhere between their 20s and 40s, while the average age of diagnosis for non-hereditary colon cancer is around 60. Additionally, cancers associated with Lynch syndrome are often located on the right side of the colon (the ascending colon), which is less common in the general population.
Not only does Lynch syndrome increase the risk of colon cancer, but it also raises the risk of several other cancers, including endometrial cancer, ovarian cancer, stomach cancer, small bowel cancer, and others. This widespread impact makes Lynch syndrome an important condition to identify early, so individuals can take steps to manage their health and monitor for signs of cancer.
READ MORE: How Common is Lynch Syndrome? 8 Stats That Matter
Colon Cancer Signs and Symptoms to Watch For
Like many forms of cancer, Lynch syndrome associated colon cancer may not present any obvious symptoms in its early stages. However, some signs that could indicate the presence of colon cancer or other cancers associated with Lynch syndrome include:
- Changes in bowel habits: Persistent diarrhea or constipation, or a feeling that your bowels are not fully empty.
- Blood in stool: Either visible or detected through a stool test.
- Unexplained weight loss: This could signal the presence of cancer.
- Fatigue: Feeling constantly tired or weak.
- Abdominal pain: Persistent or severe discomfort.
It’s crucial to note that while these symptoms can indicate colon cancer, they can also be related to other conditions. Regular screenings, especially for individuals with Lynch syndrome or a family history of the condition, are essential for catching potential problems early.
Genetic Testing and Early Detection
If you have a family history of colon cancer or other cancers associated with Lynch syndrome, it’s a good idea to discuss genetic testing with your healthcare provider. If you are diagnosed with Lynch syndrome and know about your cancer risk, you can significantly reduce that risk by catching it in its earliest, most treatable stages. Individuals with Lynch syndrome should start regular colonoscopies at an earlier age – typically around age 20-25, or 2-5 years earlier than the age at which the youngest family member was diagnosed with colon cancer.
The Importance of Accurate Testing
Lynsight’s assay, DiagMMR, provides accurate insights into your genetic makeup and the MMR functionality in your body, helping you understand whether you carry mutations that increase your risk of colon cancer. Armed with this knowledge, you and your healthcare team can develop a personalized plan to manage your health, stay proactive with screenings, and make informed decisions about your cancer risk.
Accurate testing is especially important because Lynch syndrome can be difficult to identify based on family history or symptoms alone. Many people with this condition may not know they’re at risk until cancer develops. By directly analyzing MMR activity, DiagMMR goes beyond traditional genetic testing to assess how your body is functioning at the cellular level – giving you a clearer, more immediate picture of your cancer risk.
Conclusion
The link between Lynch syndrome and colon cancer is clear – but so is the opportunity to act. Knowing your genetic risk can change the way you approach your health, offering clarity and a plan for moving forward. If you have a personal or family history of colon cancer, don’t wait. Talk to your doctor or a genetic counselor about how you can get tested for Lynch syndrome.
Stay informed about Lynch syndrome. Check out our resources for information on early detection, accurate testing, and prevention.