The colon is the first six feet of the large intestine. Cancer arising in the colon is curable if caught in the early stages, says the National Institutes of Health. According to the National Cancer Institute, options available in the treatment of colon cancer are surgery, radiation therapy and chemotherapy. Diverse combinations of these options may be used. Different stages of colon cancer determine the choice of treatment options.
Stage 0
This stage is called carcinoma in situ. The cancer has not grown beyond the lining or epithelium of the colon. The American Cancer Society suggests that surgery is the mode of treatment at this stage. The cancer can be removed by simple excision or polypectomy, using a laparoscope. Large cancers at this stage may require a more extensive surgery ,called colectomy, involving removal of a section of the colon. The two healthy ends of the cut colon are rejoined by a procedure called anastomosis.
Stage 1
Cancers at this stage have grown through several layers of the colon but have not spread beyond the colon. The ACS recommends colectomy or resection of the affected segment of the colon with removal of neighboring lymph nodes.
Stage 2
According to the ACS, cancers at this stage have grown right through the full thickness of the colon and may have spread into nearby structures but have not spread up to the lymph nodes.
Surgery is also the first choice in these cases, involving colectomy and removal of neighboring lymph nodes. In some cases, chemotherapy is added after surgery, particularly in high-grade cancers with the risk of recurrence, as in instances where residual cancer is suspected or lymph node spread is confirmed. The ACS reports that the risk of recurrence is high in colon cancers that have caused obstruction or perforation of the intestine, warranting follow-up, or adjuvant, chemotherapy. Suspicion of residual cancer may mean the addition of radiation therapy to the prescribed treatment, after surgery.
Stage 3
Stage 3 cancers have spread beyond the colon into nearby lymph nodes but not to other parts of the body. The treatment options here are colectomy with removal of the lymph nodes, explains the ACS. This is usually followed by chemotherapy with or without radiation therapy. Radiation therapy following surgery may be the doctor's choice if the tumor is at high risk for recurrence. In stage 3 cases where patients are too sick for surgery, a combination of chemotherapy and radiation therapy may be used.
Stage 4
Stage 4 cancers have spread beyond the colon to other parts of the body, like the liver, lungs or ovaries. Surgery may not cure the cancer in a majority of cases, reports the ACS. In some cases, the cancer can be successfully removed and localized areas of spread, called metastases, can also be removed from the liver and lungs. In other cases, surgery may be to prolong life and relieve discomfort. Obstruction of the intestine by the cancer may warrant bypass surgery or the placing of a rubber tube or stent to keep the intestine open and prevent further obstruction.
Chemotherapy is used in most patients at this stage. It is intended to shrink the cancer before surgery or as a follow-up to surgery to prevent or slow recurrence. Targeted therapy or immunotherapy is often combined with chemotherapy in these cases. Radiation therapy is also used at this stage, but usually to relieve severe symptoms like pain or prevent their occurrence.
Recurrent Cancer
According to the ACS, recurrence can take place at the original site of the tumor or at a distance from the site of origin, usually the liver. Treatment generally follows the format for stage 4 cancers. Where possible, the cancer is surgically removed. Surgery may also be used to relieve symptoms. Chemotherapy may precede the surgical removal of recurrent colon cancer, usually to shrink it and make surgery easier. Chemotherapy with or without targeted therapy usually follows surgery to increase the chances of cure or further prolong life. Chemotherapy may also be used alone in cases where the recurrent cancer is inoperable. The same combinations used in stage 4 cancers are used here. Radiation therapy is utilized here usually to prevent or relieve discomfort and pain.
