Colon Cancer

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Cancer that forms in the tissues of the colon (the longest part of the large intestine). Most colon cancers are adenocarcinomas (cancers that begin in cells that make and release mucus and other fluids).

Colorectal cancer may not cause any signs or symptoms in its early stages because there is lots of room in the abdomen where a tumour can grow. Symptoms often appear once the tumour blocks (obstructs) or causes ulcerations (sores) in the colon or rectum.

A sign is something that can be observed and recognized by a doctor or healthcare professional (for example, a rash). A symptom is something that only the person experiencing it can feel and know (for example, pain or tiredness). Colorectal cancer may not cause any signs or symptoms in its early stages because there is lots of room in the abdomen where a tumour can grow. Symptoms often appear once the tumour blocks (obstructs) or causes ulcerations (sores) in the colon or rectum. The signs and symptoms of colorectal cancer can also be caused by other health conditions. It is important to have any unusual symptoms checked by a doctor

  • Change in bowel habits
    • Narrowing of stools (due to partial blockage of the large intestine)
    • Red, bloody bowel movements
    • Black, tarry bowel movements (melena)
    • Mucus in the stool
    • Persistent diarrhea
    • Persistent constipation
    • Rectal bleeding between bowel movements
    • Feeling that the bowel has not completely emptied
    • Urgent need to have a bowel movement
  • Abdominal discomfort
    • Pain
    • Cramps
    • Gas
    • Bloating
    • Fullness
    • A lump may be felt in the abdomen
  • Changes to digestion
    • Nausea
    • Vomiting
    • Loss of appetite
  • Fatigue
  • Weight loss
  • Anemia
    • Usually a result of bleeding from within the bowel
    • Causes fatigue, shortness of breath and weakness
  • Bowel obstruction (blockage)
  • Perforation (piercing) of the bowel (large intestine) accompanied by fever and pain
  • Weakness
  • Frequent urinary tract infection (as a result of fistula formation or perforation into the bladder)
  • Colorectal cancer symptoms depend on where the tumour is located in the colon or if it is in the rectum. Blockage of the ascending (right-side) colon is unlikely because the stool in this part of the colon is still in liquid form and can pass a partial blockage or constriction quite easily
  • Black, tarry bowel movements, called melena, are usually associated with tumours of the ascending colon
  • Bright red rectal bleeding either mixed with or coating the surface of the stool is most common with tumours of the descending (left-side) colon or rectum
  • Severe abdominal pain< /li>
  • Buildup of fluid in the abdomen (ascites)
  • Enlargement of the liver (hepatomegaly)
  • Jaundice
  • Enlarged lymph nodes
  • Pain in the hip or buttock
  • Breathing problems
  • Loss of appetite

Cancer treatment is given by cancer specialists (oncologists). Some specialize in surgery, some in radiation therapy and others in chemotherapy (drugs). These doctors work with the person with cancer to decide on a treatment plan.

Treatment plans are designed to meet the unique needs of each person with cancer. Treatment decisions for colorectal cancer are based on:

  • Stage.
  • Type of cancer (colon or rectal)
  • Location of the tumour
  • Whether the cancer has recurred or spread
  • The person’s overall health
  • Surgery
    • Removal of a polyp (polypectomy)
    • A polyp is not a cancer, but there may be cancer cells within a polyp. If polyps are found during colonoscopy or sigmoidoscopy, they are surgically removed and checked for cancer cells.
    • Removal of tumours in the mucosa layer of the colon (local excision or endoscopic mucosal resection)
    • Removal of part of the colon (hemicolectomy, partial bowel resection)
    • Removal of all of the colon (colectomy, total bowel resection)
    • Removal of all of the colon, rectum and pelvic organs (pelvic exenteration)
    • Removal of colon cancer that has spread to the liver or lung (metastases)
  • Chemotherapy.
    • Chemotherapy for colon cancer may include:
    • 5-fluorouracil (Adrucil, 5-FU))
    • Folinic acid (leucovorin)
    • Oxaliplatin (Eloxatin)
    • Capecitabine (Xeloda)
    • Irinotecan (Camptosar, CPT-11)
    • Raltitrexed (Tomudex)
    • Chemotherapy is sometimes injected directly into the hepatic artery in the liver to treat liver metastases (hepatic artery infusion). This approach is not a common practice in Canada.
  • Targeted therapy
    • It may be given alone or combined with chemotherapy for treatment of advanced disease
    • Targeted therapy for colon cancer may include:
    • Bevacizumab (Avastin)
    • Cetuximab (Erbitux)
    • Panitumumab (Vectibix)
  • Radiation
    • May include external beam radiation therapy given to relieve symptoms of advanced disease.
  • Radiofrequency ablation
    • Sometimes used to treat liver metastases
  • Follow-up after treatment is finished
    • It is important to have regular follow-up visits, especially in the first 2–3 years after treatment.