Colon Cancer Treatment

Colon Cancer Treatment

Colon cancer treatment programs vary by the stage of the disease at the time of surgery (if operable) or at the time of diagnosis (if metastatic or not operable). Your surgeon or oncologist will determine your stage based on criteria in the pathology report (if operable) or radiology scans. Colon cancer stage is based on a combination of tumor properties and whether it is found in lymph nodes or organs distant from the colon (such as liver or lungs).

Detailed Guide: Colon and Rectum Cancer – How Is Colorectal Cancer Staged?

Colon Cancer Treatment (by Stage)

Stage I (93% alive at 5 years)

    • Observation
      • colonoscopy surveillance for new cancers
      • Checkups and CEA tests every 3-6 months for 3 years, every 6 months for 5 years

Stage IIA (85% alive at 5 years)

    • Observation vs, Chemotherapy to reduce relapse risk
    • Reasons to consider chemotherapy (FOLFOX):
      • Age/overall health and vigor
      • Intestinal obstruction due to tumor
      • Perforation of the large intestine by the tumor
      • Patient preference
      • “Microsatellite instability” of the tumor (a genetic property of certain colon tumors currently under investigation but used by some oncologists as a criterion for chemotherapy)Whether treated or not: Checkups and CEA tests every 3-6 months for 3 years, every 6 months for 5 years; CT scans annually for 3 years based on risk of recurrence

Stage IIB (72% alive at 5 years)

    • Chemotherapy (FOLFOX) to reduce relapse risk
    • Checkups and CEA tests every 3-6 months for 3 years, every 6 months for 5 years; CT scans annually for 3 years

Stage III (44-83% alive at 5 years depending on # of positive lymph nodes and tumor invasiveness)

    • Chemotherapy (FOLFOX) to reduce relapse risk
    • Checkups and CEA tests every 3-6 months for 3 years, every 6 months for 5 years; CT scans annually for 3 years

Stage IV (8% alive at 5 years)

    • 1 st line therapy: FOLFOX (or FOLFIRI) + avastin
    • 2nd line therapy:FOLFIRI (or FOLFOX) + avastin OR
      • Irinotecan + cetuximab (or panitumumab) [if tumor is not mutated at the K-Ras oncogene]
    • 3 rd line therapy: panitumumab (K-ras non-mutated) OR
      • Irinotecan + cetuximab (K-ras non-mutated) OR
      • Clinical Trial (if K-Ras mutated)

Chemotherapy Drugs for Colon Cancer

  • 5-FU (also: 5-fluorouracil)- the oldest drug in continuous use for colon cancer. It is now the anchor drug in many combinations (see below), and rarely used alone. It can be given as a quick injection or as a slow infusion over a number of days using a wearable pump. Main side effects: Diarrhea, mouth sores, rash/pain of hands and feet, weight gain. Uncommon side effects: Vertigo/dizziness, excessive tearing, chest pain. A small percentage of women are intolerant of 5-FU due to an inherited enzyme deficiency (which can be screened for), and can become seriously ill even from small doses of 5-FU.
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  • Leucovorin- is not formally a chemotherapeutic, but a B-vitamin derivative that potentiates the effects of 5-FU. It is given as a 2 hour infusion (for larger doses). There are no serious side effects.
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  • Oxaliplatin- is the mainstay of first line treatment of stage II-IV colon cancer, in combination with 5-FU, Leucovorin and avastin (avastin in stage IV disease only). It is given as a 2-3 hour infusion every 2 weeks. Main side effects: Neuropathy (deadening of nerve endings in hands/feet/mouth) with paradoxical pain, extreme cold sensitivity of hands and mouth (usually 1-5 days after an infusion), nausea/vomiting, elevation of liver tests. Neuropathy is usually reversible after a dose, but can become permanent and debilitating after repetitive dosing, so constant monitoring is essential. Women are prone to laryngeal dysesthesia during or immediately after the infusion, where the sensation of the throat closing occurs, though it is not physically happening. Oxaliplatin can suppress the bone marrow, causing white cell, red cell, and platelet deficiencies, though its effects are modest compared with most other chemotherapy drugs.
  • Irinotecan-often used in 2 nd line/3 rd line therapy, in various combinations with 5-FU, leucovorin, cetuximab, and avastin, but only in stage IV disease. It is given as a 90 minute infusion on schedules that vary based on the regimen. The main toxicity is diarrhea, which can be severe or even fatal if not monitored and treated. Patients are given specific instructions on how to deal with diarrhea at home, using OTC anti-diarrheals or other prescription medications. Irinotecan also suppresses the bone marrow to varying degrees, and causes hair loss, nausea and vomiting.
  • Capecitabine (Xeloda)- pill form of 5-FU, which is turned into 5-FU in cells of the tumors. Side effects: as for 5-FU, with more pronounced diarrhea, hand/foot syndrome, mouth sores.

All patients on chemotherapy are at risk for possibly fatal infection if white cell counts drop, and must report any fever (especially if >100.5 F), chills, or other infective symptoms to their doctor immediately or otherwise report to an emergency room without delay.

Chemotherapy Combination Regimens for Colon Cancer

  • FOLFOX- 5-FU (as injection and as 46 hour infusion by pump), Leucovorin (injection), oxaliplatin (injection). Repeated every 2 weeks for 6 months—or longer. Can be combined with avastin.
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  • FOLFIRI- 5-FU (as injection and as 46 hour infusion by pump), Leucovorin (injection), irinotecan (injection). Repeat every 2 weeks for 6 months-or longer. Can be combined with avastin.
  • Irinotecan/cetuximab- both as injections- cetuximab weekly and irinotecan at varying scedhules based on MD preference (K-ras non-mutated).
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  • XELOX- combination of capecitabine (daily for 14 days every 3 wks) + oxaliplatin (once every 3 weeks), where capecitabine substitutes for 5-FU and leucovorin. Sometimes used for convenience, instead of FOLFOX. Appears to be therapeutically equivalent to FOLFOX.

Biologic Agents for Colon Cancer Biology

  • Cetuximab- an antibody that targets the EGF receptor on tumor cells. It can only be used against K-ras mutated tumors. It is given weekly as a 60 minute infusion. It can cause infusion reactions (chills, fever, etc.) and steroids and other premedications are used to prevent reactions. Cetuximab is generally used with irinotecan in 2 nd or 3 rd line therapy. Side effects include possibly severe skin rash (treated with topical creams or antibiotic pills), diarrhea.
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  • Panitumumab- Also an EGFR inhibitor antibody but given every 2 weeks. Side effects as per cetuximab.
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  • Avastin-antibody against the blood vessel promoting substance in the body VEGF, in the hope it would starve tumor of blood supply. Avastin is given as a 15-30 min infusion on varying schedules, usually with FOLFOX or FOLFIRI combinations in stage IV colon cancer. Main side effects include: bleeding, clotting, high blood pressure, protein in the urine. Serious but rare side effect is perforation of the intestine. Avastin impairs wound healing and must be avoided 6-8 weeks before and after major elective surgery.