In the laboratory, the pathologist will examine the margins the removed piece of bowel. He will also determine the depth of penetration of the cancer as well as any lymph node involvement. This is referred to as Pathological Staging. The need for further treatment is dependent on the full staging of the cancer.
Treatment depends on many things, including the stage of the cancer. In general, treatments may include:
- Chemotherapy to kill cancer cells
- Radiation therapy to destroy cancerous tissue
- Surgery (most often a colectomy) to remove cancer cells
Almost all patients with stage III colon cancer should receive chemotherapy after surgery for approximately 6 - 8 months. This is called adjuvant chemotherapy. The chemotherapy drug 5-fluorouracil has been shown to increase the chance of a cure in certain patients.
Chemotherapy is also used to improve symptoms and prolong survival in patients with stage IV colon cancer.
- Irinotecan, oxaliplatin, capecitabine, and 5-fluorouracil are the three most commonly used drugs.
- Monoclonal antibodies, including cetuximab (Erbitux), panitumumab (Vectibix), bevacizumab (Avastin), and other drugs have been used alone or in combination with chemotherapy.
** Radiation
Although radiation therapy is occasionally used in patients with colon cancer, it is usually used in combination with chemotherapy for patients with stage III rectal cancer.
For patients with stage IV disease that has spread to the liver, various treatments directed specifically at the liver can be used. This may include:
- Burning the cancer (ablation)
- Delivering chemotherapy or radiation directly into the liver
- Freezing the cancer (cryotherapy)
- Surgery
Stage 0 colon cancer may be treated by removing the cancer cells, often during a colonoscopy. For stages I, II, and III cancer, more extensive surgery is needed to remove the part of the colon that is cancerous.