Lynch syndrome is a condition that increases the predisposition for certain cancers. People with Lynch syndrome should undergo frequent cancer screening for early diagnosis and treatment. But if Lynch syndrome remains underdiagnosed, these individuals cannot get the care that they need. According to reporting from Izzy Wood on Drug Target Review, new research found that the existing screening measures for Lynch syndrome often contributes to younger individuals not receiving diagnoses in a timely manner. 

Determining the Impact of Living Undiagnosed 

In research published in the Journal of the National Comprehensive Cancer Network, the authors note that Lynch syndrome is often caused by a mismatch repair gene mutation. However, they continued, mismatch repair deficiency may also occur due to methylation of the MLH1 gene; in fact, as much as 75% of tumors with this deficiency show signs of methylation. The research team wanted to explore MLH1 methylation as an underexplored and poorly known cause of this condition. If methylation is found just in the tumor but not in bodily tissues, it is not characteristic of Lynch syndrome. Alternatively, methylation in normal tissue is a hallmark of this condition. Learn more about gene methylation. 

Within this study, the research team wanted to see how often MLH1 methylation occurred in people with colorectal cancer who also had mismatch repair deficiency. The findings show that:

• Anywhere between 25% to 75% of people under 55 years old had tumors and blood that showed signs of methylation. This suggested that these individuals had this condition but were undiagnosed.
• In younger people with endometrial cancer, 15-20% were believed to have undiagnosed Lynch syndrome following methylation testing. 

As a result, the researchers suggest that there should be improved screening guidelines for younger individuals with endometrial or colorectal cancer. Further, they advocate for people within this group to speak with their doctors about additional oncologic screening methods. 

About Lynch Syndrome

Also known as: Hereditary non-polyposis colorectal cancer

MLH1, MSH2, MSH6, PMS2, and EPCAM gene mutations may all cause Lynch syndrome and increase the risk of developing certain cancers. These mutations are inherited in an autosomal recessive pattern, meaning that someone affected must inherit one defective gene from each parent. Outside of colorectal and endometrial cancers, Lynch syndrome may also increase the predisposition to gastric, ovarian, bile duct, brain, and pancreatic cancers (among others). 

The symptoms of this condition may include:

• Getting certain cancers before 50 years old
• Having a mismatch repair deficiency or high-level microsatellite instability
• Developing colorectal cancer and other types of cancer at the same or different times
• Colon polyps