Stages & Treatment of Colorectal Cancer | Dr Meenu Walia | DNB Medical Oncologist

Stages of Colorectal Cancer

Stage 0 : Since these cancers have not grown beyond the inner lining of the colon, surgery to take out the cancer is all that is needed. This may be done in most cases by polypectomy (removing the polyp) or local excision through a colonoscope. Colon resection (colectomy) may occasionally be needed if a tumor is too big to be removed by local excision.

Stage I : These cancers have grown through several layers of the colon, but they have not spread outside the colon wall itself (or into the nearby lymph nodes). Stage I includes cancers that were part of a polyp. If the polyp is removed completely, with no cancer cells in the edges (margins), no other treatment may be needed. If the cancer in the polyp was high grade (see “How is colorectal cancer staged?”) or there were cancer cells at the edges of the polyp, more surgery may be advised. You may also be advised to have more surgery if the polyp couldn’t be removed completely or if it had to be removed in many pieces, making it hard to see if cancer cells were at the edges.

For cancers not in a polyp, partial colectomy ─ surgery to remove the section of colon that has cancer and nearby lymph nodes ─ is the standard treatment. You do not need any additional therapy.

Stage II : Many of these cancers have grown through the wall of the colon and they may extend into nearby tissue. They have not yet spread to the lymph nodes.

** Surgery to remove the section of the colon containing the cancer along with nearby lymph nodes (partial colectomy) may be the only treatment needed. But your doctor may recommend chemotherapy (chemo) after surgery (adjuvant chemo) if your cancer has a higher risk of coming back because of certain factors, such as:

• The cancer looks very abnormal (is high grade) when viewed under a microscope.
• The cancer has grown into nearby organs.
• The surgeon did not remove at least 12 lymph nodes.
• Cancer was found in or near the margin (edge) of the surgical specimen, meaning that some cancer may have been left behind.
• The cancer had blocked off (obstructed) the colon.
• The cancer caused a perforation (hole) in the wall of the colon.
• The main options for chemo for this stage include 5-FU and leucovorin (alone) or capecitabine, but other combinations may also be used.

** If your surgeon is not sure all of the cancer was removed because it was growing into other tissues, he or she may advise radiation therapy to try to kill any remaining cancer cells. Radiation therapy can be given to the area of your abdomen where the cancer was growing.

Stage III : In this stage, the cancer has spread to nearby lymph nodes, but it has not yet spread to other parts of the body.

** Surgery to remove the section of the colon containing the cancer along with nearby lymph nodes (partial colectomy) followed by adjuvant chemo is the standard treatment for this stage. Either the FOLFOX (5-FU, leucovorin, and oxaliplatin) or CapeOx (capecitabine and oxaliplatin) regimens are used most often, but some patients may get 5-FU with leucovorin or capecitabine alone based on their age and health needs.

** In people who aren’t healthy enough for surgery, radiation therapy and/or chemo may be options.

Stage IV : The cancer has spread from the colon to distant organs and tissues. Colon cancer most often spreads to the liver, but it can also spread to other places such as the lungs, peritoneum (the lining of the abdominal cavity), or distant lymph nodes.

Treatment of Colorectal Cancer

Surgery

** Surgery is the mainstay of treatment and involves in block removal of diseased segment with adequate margins, surrounding tissue and lymph nodes. The names given to such resections are right hemicolectomy, transverse colectomy, left hemicolectomy, sigmoid colectomy, and subtotal colectomy.

1. Polypectomy: If the cancer is found in a polyp (a small piece of bulging tissue), the polyp is often removed during a colonoscopy.
2. Local excision: If the cancer is found on the inside surface of the rectum and has not spread into the wall of the rectum, the cancer and a small amount of surrounding healthy tissue is removed.
3. Resection: If the cancer has spread into the wall of the rectum, the section of the rectum with cancer and nearby healthy tissue is removed. Sometimes the tissue between the rectum and the abdominal wall is also removed. The lymph nodes near the rectum are removed and checked under a microscope for signs of cancer.
4. Pelvic exenteration: If the cancer has spread to other organs near the rectum, the lower colon, rectum, and bladder are removed. In women, the cervix, vagina, ovaries, and nearby lymph nodes may be removed. In men, the prostate may be removed. Artificial openings (stoma) are made for urine and stool to flow from the body to a collection bag.

** Radiation therapy or chemotherapy may be given before surgery to shrink the tumor, make it easier to remove the cancer, and lessen problems with bowel control after surgery. Treatment given before surgery is called neoadjuvant therapy. Even if all the cancer that can be seen at the time of the operation is removed, some patients may be given radiation therapy or chemotherapy after surgery to kill any cancer cells that are left. Treatment given after the surgery, to lower the risk that the cancer will come back, is called adjuvant therapy.

Radiation therapy

** Radiation therapy is a cancer treatment that uses high-energy beams or other types of radiation to kill cancer cells. There are two types of radiation therapy. External radiation therapy uses linear accelerators outside the body to send radiation toward the cancer. Internal radiation therapy (Brachytherapy) uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.

Chemotherapy

** Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly in the cerebrospinal fluid, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.

Targeted therapy

** Targeted therapy is a type of treatment that uses drugs or other substances to identify and attack specific cancer cells without harming normal cells. Monoclonal antibody therapy is a type of targeted therapy being studied in the treatment of rectal cancer.

**  Monoclonal antibody therapy uses antibodies made in the laboratory from a single type of immune system cell. These antibodies can identify substances on cancer cells or normal substances that may help cancer cells grow. The antibodies attach to the substances and kill the cancer cells, block their growth, or keep them from spreading. Monoclonal antibodies are given by infusion. They may be used alone or to carry drugs, toxins, or radioactive material directly to cancer cells.