Colorectal cancer is a type of cancer that begins in the rectum or colon. Depending on the location where it begins, medical professionals might also refer to it as rectal cancer or colon cancer. The condition typically begins as polyps on the inner lining of the rectum or colon. Polyps are growths that may initially be benign, but some polyps can become cancerous over time. There are different types of colorectal cancer. The most common type is adenocarcinoma, which begins in the cells that create the mucus that lubricates the inside of the rectum and colon. Other types include carcinoid tumors, gastrointestinal stromal tumors, lymphomas, and sarcomas.
What are signs and symptoms of colorectal cancer?
When colorectal cancer first develops, it may not cause any symptoms. If symptoms do develop, they can include a change in bowel habits, bloody stool, constipation, diarrhea, abdominal pain, and unexplained weight loss. As the condition does not always cause symptoms, colorectal cancer screenings are important. The U.S. Preventive Services Task Force recommends screening for people ages 45 to 75 years.
Is colorectal cancer genetic?
Colorectal cancer may be genetic in some cases. In around 10% to 30% of cases, a person with colorectal cancer also has a family member who has had the condition. Variants in genes have been identified in around 5% to 6% of cases. It is unclear if the remaining cases develop due to inherited genes or shared exposure to risk factors among families. Lynch syndrome is an inherited condition responsible for about 2% to 4% of colorectal cancer cases. If a family member has Lynch syndrome, a person can contact their doctor about screening for the condition.
What is the life expectancy of someone with colorectal cancer?
The 5-year relative survival rate for colorectal cancer is 63% for all stages combined, according to the American Cancer Society. For localized cancer, the 5-year relative survival rate is 91%. It is 72% for regional colorectal cancer, and 13% for distant colorectal cancer. A person's doctor can provide more accurate information based on their individual circumstances. Learn more about the outlook for a person with colorectal cancer.
