Colorectal cancer is more prevalent than many people might think. The lifetime risk of developing colorectal cancer is 1 in 24 for men and 1 in 26 for women. To illustrate, in a room of 100 people, roughly a quarter will be diagnosed with colon cancer at some point in their lives.
Jenifer Dumire, BSN, RN, CVRN-BC, BHCN, CGRA High Risk & Genetic Navigator at Midland Health, highlights that colon cancer typically grows slowly and goes through a linear progression. It begins with pre-cancerous polyps, advances to adenomas, and finally becomes full-blown colon cancer. This progression usually spans about ten years. Consequently, a person who undergoes a colonoscopy without polyps can wait a decade for their next screening. However, if polyps are detected, a follow-up colonoscopy should occur in three years to confirm there are no new polyps. "Colonoscopy is the golden standard for screening because no other test can detect if there are polyps," Dumire says. Other tests reveal DNA changes that could indicate the presence of pre-cancerous or cancerous cells.
Gene mutations can hinder DNA repair processes, elevating the risk of colon cancer. These mutations may accelerate the typical ten-year progression mentioned. Lynch Syndrome is a notable mutation that can raise the risk of colon cancer. Statistics indicate about 1 in 279 people in the general population carry a Lynch Syndrome-associated mutation. Based on Midland's estimated population of 140,000, around 500 individuals might carry this mutation. However, national data suggest up to 90% of those with a Lynch Syndrome mutation remain undiagnosed. This lack of detection stems mainly from insufficient education and limited genetic testing availability.
Family history plays a crucial role in genetic testing decisions. A history of cancers linked to Lynch Syndrome—including colon, stomach, ovarian, pancreatic, kidney, bladder, ureteral, brain, small bowel, gallbladder, bile duct, and skin cancers—might justify genetic testing, especially if these cancers appeared at an early age or spanned multiple generations. Those diagnosed with Lynch Syndrome mutations may require more frequent screenings, possibly as often as every 1-2 years.
"If any of this sounds familiar to you, I urge you to have a discussion with your doctor about the need for genetic testing," Dumire advises. She emphasizes, "As with all cancer, remember early detection is the key to survival with colorectal cancer."