Colorectal cancer is the world’s third most frequent cancer type. Recognizing its risk factors, symptoms, and screening options is key to successful treatment.
Colorectal cancer (CRC), also called bowel cancer, begins with abnormal growth of cells in the large intestine. It may start in the colon or the rectum, leading to colon cancer or rectal cancer. Doctors usually place colon and rectal cancers in the same category because they have many common features. In most cases, colon cancer originates from benign growths on the inner lining of the colon, called polyps. Over time, some polyps may mutate and transform into cancerous tissues.
The exact cause of colorectal cancer is yet unknown, but certain risk factors are associated with the disease. Having a family history of colorectal cancer or ovarian, breast, and uterine cancer in women, as well as hereditary gene syndromes, previously detected polyps, or inflammatory bowel disease, may increase your risk of developing colon cancer. Ulcerative colitis or Crohn’s disease are risk factors for developing colorectal cancer, especially in people who have had it for more than 10 years. However, behavioral risk factors, such as smoking, unhealthy diet, heavy alcohol intake, and physical inactivity account for a large share of cases. Eating a lot of red or processed meats and being overweight may also raise your risk. You are more likely to develop colon cancer after 60 though it might occur at any age. According to studies, one-third of patients diagnosed with colorectal cancer are younger than 55.
Bowel cancer affects men and women almost equally. However, the lifetime risk of developing the disease is slightly higher in men (4,3% vs. 4%). According to some studies, males tend to be diagnosed younger compared to women.
Female patients may sometimes ignore signs and symptoms of colon cancer since some of them are similar to discomfort related to menstruation or other gynecological conditions. A woman’s risk of developing cancer increases after menopause.
Very often, there are no specific early symptoms of colorectal cancer until the cancerous growth has advanced. For this reason, regular screening helps to detect the disease before symptoms develop, while colon cancer is most curable.
Symptoms of colon cancer become more noticeable with the progression of the disease. They may vary from person to person, depending on the location and size of the cancer growth:
These symptoms do not necessarily indicate cancer. Many other disorders of the digestive tract can cause similar problems, including hemorrhoids, fissures, irritable bowel syndrome, etc. Visit a doctor for any complaints that last longer than a few days.
Generally, regular screenings for colon cancer should start at the age of 50 for people who do not have a family history of the disease and have no complaints. Screening may need to begin at 40 or even earlier if you have any risk factors. In people with genetically inherited polyposis syndromes in their family, screening should start at age 15-18.
There are several screening options for early detection of colon cancer, including fecal occult blood test (FOBT), fecal DNA test, colonoscopy, flexible sigmoidoscopy, and computed tomographic colonography. The best screening method is a colonoscopy. It uses a thin, flexible tube with a camera at the end to examine the large intestine from the inside. The procedure allows doctors to detect and remove polyps before they turn into cancer, or to take samples (biopsy) from suspicious areas. Polyps removed during a colonoscopy are examined to determine if they have cancerous or precancerous cells.
If the diagnosis of colon cancer is confirmed, further blood and imaging tests will be performed to evaluate the exact type, stage, and spread of the disease. ACIBADEM Cancer Centers provide rapid access to all the latest imaging tools, including chest X-ray, abdominal computed tomography (CT), ultrasonography (US), magnetic resonance imaging (MRI), endorectal ultrasonography (ERUS), positron emission tomography (PET), for detailed diagnosis of colorectal cancer.
Colon cancer prognosis and treatment depend highly on the stage at which it is discovered. Stages are classified on a scale from 0 (carcinoma in situ) to IV. In the lower stages, the cancer is confined to the colon wall, while in stage IV colon cancer has spread to distant organs (metastasized). When the disease is detected at an early stage before it has spread, the 5-year survival rate exceeds 90%. Cancer is considered cured if it does not recur within 5 years. At an advanced stage, the survival rate is lower but steadily increasing.
The death rate for colorectal cancer has been decreasing over the last decades. This is related to improved early detection thanks to screening programs. When cancer is detected earlier, it is easier to be treated. On the other hand, the treatment methods have also progressed over time. A multidisciplinary approach and comprehensive treatment received in experienced cancer centers, such as ACIBADEM, can contribute to better outcomes.
How colon cancer is treated depends on its location, stage, and many other factors. What you should know is that colorectal cancer is a treatable disease, especially if it’s diagnosed early. Depending on the case, surgery, chemotherapy, targeted therapy, immunotherapy, or radiation may be used alone or combined.