Treatment of colorectal cancer

The article was written by Specialist Doctor I Nguyen Thi Minh Thuyen - Pathologist, Pathology Department - Vinmec Danang International General Hospital.

Colon cancer is the uncontrolled growth of cells that form tumors in the colon. If you have been diagnosed with colorectal cancer, your cancer care team will discuss treatment options with you. The treatment of colon cancer will be considered depending on the stage of the disease to minimize the risks and possible side effects.

Is to treat the tumor without affecting the rest of the body. Effective local treatment for early-stage cancers. Local treatments for colorectal cancer include: Surgery and radiation
1.1 Surgery for colon cancer Surgery is often the mainstay of treatment for early colon cancer. The type of surgery depends on the stage (how far has spread) of the cancer, the location of the tumor, and the goals of the surgery.
Colon cancer surgery by resection of part of the colon , or resection of the rectum depending on the location of the tumor and adjacent lymph nodes and re-establish gastrointestinal circulation.
Types of colorectal cancer surgery include:
Polypectomy and local resection: Some early colon cancers (stage 0 and some stage I) and most polyps can be removed. removed during endoscopy. Colectomy: Surgery to remove all or part of the colon and nearby lymph nodes. Surgery for extensive colon cancer: In some cases where the cancer has spread to other organs and the tumor is blocking the colon, surgery can be done to relieve the blockage without removing part of the colon. contain cancer. Instead, the colon is cut above the tumor and attached to an opening (opening in the skin of the abdomen) for stool to pass, called an stoma. This approach can give patients enough time to recover to begin other treatments.

1.2 Radiation therapy for colon cancer Radiation therapy uses high-energy rays (such as X-rays) to kill cancer cells.
Preoperative radiotherapy helps to shrink the tumor and make it easier to remove. Radiation therapy after surgery helps kill any cancer cells that may be left behind.
Different types of radiation therapy may be used to treat colorectal cancer.
External-beam radiation therapy (EBRT) Internal radiation therapy (brachytherapy) Radioembolization If you are about to have radiation therapy, you should ask your doctor first about side effects. Short term and long term are possible. Possible side effects of radiation therapy for colorectal cancer include:
Skin irritation at the site of radiation, which can range from redness to blistering and peeling Problems with wound healing if radiation pre-operative treatment Nausea Irritate the rectum, which can cause diarrhea, intestinal cramps, or blood in the stool Urinary incontinence (fecal leakage) Bladder irritation, which can cause problems such as a feeling of need straining (the feeling of always wanting to have a bowel movement), burning or pain when urinating, or blood in the urine Tiredness. Most side effects will improve over time after treatment ends, but some problems may not go away completely. If you notice any of these side effects, talking to your doctor right away can help.

Colorectal cancer can also be treated with drugs, orally or directly into the bloodstream, called systemic therapy because they can reach cancer cells throughout the body. Depending on the type of colorectal cancer, different drugs can be used:
Chemotherapy Targeted drugs Immunotherapy 2.1 Chemotherapy for colorectal cancer The purpose of chemotherapy uses drugs to destroy cancer cells.
Systemic chemotherapy: Medicines are given straight into the bloodstream through a vein or by mouth. Drugs that enter the bloodstream and reach the whole body can help reduce the risk of colorectal cancer spreading to other parts of the body. Regional chemotherapy: Drugs are injected right into the artery leading to the tumor area, focusing chemotherapy on the cancer cells in that area, helping to reduce side effects due to limiting the amount of drug to the rest of the body. . Hepatic artery infusion, or chemotherapy given directly into the hepatic artery, is an example of chemotherapy for liver metastases. Chemotherapy is treated in cycles, after each course of treatment is a period of rest to give the body time to recover. Chemotherapy cycles usually last about 2 to 4 weeks, and patients are usually treated for several cycles.
Chemotherapy can be given at different times during colorectal cancer treatment:
Adjuvant chemotherapy after surgery: The goal is to kill any cancer cells that may be left behind after surgery, as well as cancer cells that break out of the tumor and spread to other organs but are too small to be seen on imaging tests, and help reduce the risk of the cancer coming back. Neoadjuvant chemotherapy (sometimes with radiation): Used before surgery to try to shrink the cancer and make it easier to remove, often used for rectal cancer. For advanced cancers that have spread to other organs such as the liver, chemotherapy can help shrink tumors and ease the problems they cause. While there is no cure for cancer, it often helps patients feel better and live longer. The side effects of chemotherapy depend on the type and dose of the drug and how long it is used. Common side effects of chemotherapy may include:
Hair loss Mouth sores Loss of appetite Nausea and vomiting Diarrhea Increased risk of infection (due to too few white blood cells) Easy bruising or bleeding (due to low white blood cell count) too few platelets) Fatigue (from too few red blood cells). In addition, some drugs have specific side effects such as: Hand-limb syndrome, neuropathy (nerve damage, allergic reactions).

2.2 Targeted drug therapy This method helps inhibit the growth, invasion and metastasis of the tumor but does not damage normal cells. Targeted therapy drugs work differently than chemotherapy drugs, and often have fewer side effects, and can be used with chemotherapy or alone if chemotherapy isn't working.
2.2.1 Drugs that target angiogenesis (VEGF) Vascular endothelial growth factor (VEGF) is a protein that helps tumors form new blood vessels for nutrients develope. Medicines that block VEGF action can be used to treat some colorectal cancers, including:
Bevacizumab (Avastin) Ramucirumab (Cyramza) Ziv-aflibercept (Zaltrap) These drugs are given as an intravenous (IV) every day. 2 or 3 weeks, often combined with chemotherapy, can help patients with advanced colorectal cancer live longer.
Possible side effects of drugs that target VEGF:
High blood pressure Fatigue, headache Low white blood cell count (increased risk of infection) Mouth ulcers, loss of appetite Diarrhea 2.2.2 EGFR-targeting drugs Weak receptors Epidermal growth factor receptor (EGFR) is a protein that helps cancer cells grow, usually abundant on the surface of cancer cells. EGFR-targeting drugs may be used to treat certain advanced colorectal cancers, including:
Cetuximab (Erbitux) Panitumumab (Vectibix) A possible side effect of EGFR-targeting drugs is a rash (like a rash). such as acne) on the face and chest, which can sometimes become infected, and can lead to peeling skin.
2.2.3 Another targeted medication Regorafenib (Stivarga) is a type of target called a kinase inhibitor. Kinases are proteins on or near the surface of cells that carry important signals to the cell's control center. Regorafenib blocks certain protein kinases that help tumor cells grow or help form new blood vessels to feed tumors. Blocking these proteins can help stop the growth of cancer cells.
The drug is used to treat advanced colorectal cancer, when other drugs are no longer helpful, and is taken by mouth.
2.3 Immunotherapy for colorectal cancer Immunotherapy is the use of drugs that help the body's immune system recognize and destroy cancer cells, possibly treating some colorectal cancers evolution.
The most common side effects include fatigue, diarrhea, skin rash and itching.
Discuss side effects with your cancer care team, and tell them about any side effects or changes you notice during chemotherapy so they can be treated right away. In some cases, the dose of chemotherapy drugs may need to be reduced, or the treatment may need to be delayed or stopped so it doesn't get worse.

Article referenced source: American Cancer Society