Colorectal Cancer
Introduction : Colon (colorectal) cancer starts in your colon (large intestine), the long tube that helps carry digested food to your rectum and out of your body.
Colon cancer develops from certain polyps or growths in the inner lining of your colon. Colon cancer that’s not detected or treated may spread to other areas of your body.
You can have colon cancer without having symptoms. If you do have symptoms, you may not be sure if changes in your body are signs of colon cancer. That’s because some colon cancer symptoms are similar to symptoms of less serious conditions. Common symptoms of colon cancer include:
- Blood on or in your stool (poop): Talk to a healthcare provider if you notice blood in the toilet after you poop or after wiping, or if your poop looks dark or bright red. It’s important to remember blood in poop doesn’t mean you have colon cancer. Other things — from hemorrhoids to anal tears to eating beets — may change your poop’s appearance. But it’s always better to check with a healthcare provider any time you notice blood in or on your stool.
- Persistent changes in your bowel habits (how you poop): Talk to a healthcare provider if you have persistent constipation and/or diarrhea, or if you feel as if you still need to poop after going to the bathroom.
- Abdominal (belly) pain: Talk to a healthcare provider if you have belly pain with no known cause, that doesn’t go away or hurts a lot. Many things may cause belly pain, but it’s always best to check with a healthcare provider if you have unusual or frequent belly pain.
- Bloated stomach: Like belly pain, there are many things that may make you feel bloated. Talk to a healthcare provider if your bloated belly lasts for more than a week, gets worse or you have other symptoms like vomiting or blood in or on your poop.
- Unexplained weight loss: This is a noticeable drop in your body weight when you’re not trying to lose weight.
- Vomiting: Talk to a healthcare provider if you’ve been vomiting periodically for no known reason or if you vomit a lot in 24 hours.
- Fatigue and feeling short of breath: These are symptoms of anemia. Anemia may be a sign of colon cancer.
Lifestyle choices that are risk factors for colon cancer
- Smoking: Using tobacco products, including chewing tobacco and e-cigarettes, increases your risk of developing colon cancer.
- Excessive alcohol use: In general, men and people AMAB should limit beverages containing alcohol to two servings a day. Women and people AFAB should limit beverages containing alcohol to one serving a day. Even light alcohol use can increase your risk of developing cancer.
- Having obesity: Eating high-fat, high-calorie foods may affect your weight and increase your risk of colon cancer.
- Having a diet that includes lots of red meat and processed meat: Processed meat includes bacon sausage and lunchmeat. Healthcare providers recommend you limit red meat and processed meat to two servings a week.
- Not exercising: Any kind of physical activity may reduce your risk of developing colon cancer.
Medical conditions that increase colon cancer risk
- Inflammatory bowel disease: People who have conditions like chronic ulcerative colitis and Crohn’s colitis, which cause inflammation in their colon lining, may have an increased risk of colon cancer. The risk increases if you have inflammatory bowel disease that lasts more than seven years and affects large parts of your colon.
- Inherited conditions: Certain conditions like Lynch syndrome and familial adenomatous polyposis may increase your risk of developing colon cancer. Colon cancer may happen if you inherit a gene that causes cancer.
- A family history of colon and other kinds of cancer: If a close family member has colon cancer, you may have an increased risk of developing the condition. Close family members include your biological parents, siblings and children. Your risk may be higher if any biological family member developed colon cancer before age 45.
- A family history of polyps: If your parent, sibling or child has an advanced polyp, you may have an increased risk of getting colon cancer. An advanced polyp may be a large polyp. Medical pathologists may characterize a polyp as being advanced if they see certain changes in the polyp when they look at it under a microscope that are signs the polyp may contain cancerous cells.
- Many polyps: People with numerous colon polyps — including adenomas, serrated polyps or other types of polyps — often have an increased risk of developing polyps and colon cancer. People may inherit a tendency toward having many colon polyps.
Healthcare providers use several tests to diagnose colon cancer. Those tests include:
- Complete blood count (CBC).
- Comprehensive metabolic panel (CMP).
- Carcinoembryonic antigen (CEA) assay: Cancer cells and normal cells release CEA into your bloodstream. High CEA levels may be a sign of colon cancer.
- X-rays.
- Computed tomography (CT) scan.
- Magnetic resonance imaging (MRI) scan.
- Positron emission tomography (PET) scan.
- Ultrasound.
- Biopsy.
Surgery is the most common colon cancer treatment. There are different colon cancer surgeries and procedures:
- Polypectomy: This surgery removes cancerous polyps.
- Partial colectomy: This is also called colon resection surgery. Surgeons remove the section of your colon that contains a tumor and some surrounding healthy tissue. They’ll reconnect healthy colon sections in a procedure called anastomosis.
- Surgical resection with colostomy: Like a colectomy, surgeons remove the section of your colon that contains a tumor. In this surgery, however, they can’t connect healthy colon sections. Instead, they do a colostomy. In a colostomy, your bowel is moved to an opening in your abdominal wall so your poop is collected in a bag.
- Radiofrequency ablation: This procedure uses heat to destroy cancer cells.
Healthcare providers may combine surgery with adjuvant therapy. This is cancer treatment done before or after surgery. They may also use these treatments for colon cancer that has spread or come back. Treatments may include:
- Chemotherapy: Healthcare providers may use chemotherapy drugs to shrink tumors and ease colon cancer symptoms.
- Targeted therapy: This treatment targets the genes, proteins and tissues that help colon cancer cells grow and multiply. Healthcare providers often use a type of targeted therapy called monoclonal antibody therapy. This therapy uses lab-created antibodies that attach to specific targets on cancer cells or cells that help cancer cells grow. The antibodies kill the cancer cells.
- Immunotherapy:
The stage wise 5-year survival percentages
Colon Cancer
- Stage 1: ~90%
- Stage 2: ~75%
- Stage 3: ~50–60%
- Stage 4: ~14%
Rectal Cancer
- Stage 1: ~88–90%
- Stage 2: ~70–75%
- Stage 3: ~45–50%
- Stage 4: ~14%
You may not be able to prevent colon cancer, but you can reduce your risk of developing the condition by managing risk factors:
- Avoid tobacco. If you smoke and want help quitting, talk to a healthcare provider about smoking cessation programs.
- Use moderation when you drink beverages containing alcohol.
- Maintain a healthy weight.
- Eat a healthy diet. Add fruit and vegetables to your diet and cut back on red meat processed foods, and high-fat and high-calorie foods. Drinking coffee may lower your risk of developing colon cancer.
- Keep track of your family medical history. Colon cancer can run in families. Tell your healthcare provider if your biological parents, siblings or children have colon cancer or an advanced polyp or if any of your family has cancer before age 45.
- Follow colon cancer screening guidelines. Ask your healthcare provider when you should have colon cancer screening. If you have chronic irritable bowel disease or a family history of colon cancer, your healthcare provider may recommend you start screening earlier than age 45.
A colonoscopy is the most common screening test for colon cancer. Other tests include:
- Fecal immunochemical test (FIT): This test detects hidden blood in your poop. Medical pathologists test samples of your poop for blood that you may not see just by looking.
- Guaiac-based fecal occult blood test (gFOBT): Like the FIT, this test looks for blood in poop that may not be visible.
- Fecal DNA test: This test looks for signs of genetic mutations and blood products in your poop.
- Flexible sigmoidoscopy: Healthcare providers use a flexible scope called a sigmoidoscope to see inside your lower colon and rectum.
- Virtual colonoscopy: A virtual colonoscopy is an X-ray that looks for polyps, tumors and ulcers (sores) in your colon and rectum.