Colorectal cancer is a type of cancer that begins in the colon or rectum. It is the third most common cancer in both men and women, and the second leading cause of cancer-related deaths in the United States. However, it is also one of the most preventable cancers through screening and early detection.
Causes and Risk Factors
The exact cause of colorectal cancer is unknown, but there are several factors that increase the risk of developing it. Age is the biggest risk factor, as most cases occur in people over the age of 50. Other risk factors include:
Family history of colorectal cancer or polyps
Personal history of inflammatory bowel disease (IBD), such as Crohn’s disease or ulcerative colitis
Inherited gene mutations, such as Lynch syndrome or familial adenomatous polyposis (FAP)
Sedentary lifestyle and lack of physical activity
High consumption of processed and red meats
Smoking and heavy alcohol consumption.
In the early stages, colorectal cancer may not cause any symptoms. However, as the cancer grows and spreads, symptoms may include:
Change in bowel habits, such as diarrhea, constipation, or narrowing of the stool
Blood in the stool
Abdominal pain or cramping
Unexplained weight loss
Fatigue and weakness
Screening and Diagnosis
Screening for colorectal cancer is important because it can detect precancerous polyps and early-stage cancer, which are more easily treated. The American Cancer Society recommends that people at average risk of colorectal cancer begin regular screening at age 45. However, people with a family history of colorectal cancer or certain other risk factors may need to start screening earlier.
There are several screening tests available, including:
Colonoscopy: a procedure in which a long, flexible tube with a camera is inserted into the rectum to examine the entire colon and rectum.
Fecal immunochemical test (FIT): a test that checks for blood in the stool
Stool DNA test: a test that checks for genetic changes in the stool that may indicate the presence of cancer or precancerous polyps.
Flexible sigmoidoscopy: a procedure in which a shorter, flexible tube with a camera is inserted into the rectum to examine the lower part of the colon.
If a screening test detects something abnormal, further testing may be needed to diagnose colorectal cancer. This may include a biopsy, in which a small piece of tissue is removed and examined under a microscope.
The treatment for colorectal cancer depends on the stage of the cancer and other factors, such as the person’s overall health. Treatment options may include:
Surgery: the most common treatment for early-stage colorectal cancer, in which the cancer and surrounding tissue are removed.
Chemotherapy: drugs that are used to kill cancer cells or prevent them from growing Radiation therapy: high-energy beams of radiation that are used to kill cancer cells Targeted therapy: drugs that target specific molecules that help cancer cells grow
There are several ways to reduce the risk of developing colorectal cancer, including:
Getting regular screening tests
Eating a healthy diet that is high in fiber and low in processed and red meats
Maintaining a healthy weight and being physically active
Limiting alcohol consumption
Colorectal cancer is a common and potentially deadly disease, but it is also highly preventable through screening and early detection. If you are at average risk of colorectal cancer, talk to your doctor about when to start screening and which tests are right for you. By taking steps to reduce your risk and catch any potential cancer early.