Advanced, or stage IV, colon cancer is characterized by tumors that have spread from the colon to nearby lymph nodes and other vital organs, such as the liver and lungs. Unlike treatments in the early stages of disease that aim to cure the cancer, treatments for advanced colon cancer are designed to slow the spread of the disease and improve the patient's overall survival and quality of life.
Surgery
According to the Memorial Sloan Kettering Cancer Center, up to 75 percent of patients with advanced colon cancer will develop liver metastases. Some patients my also develop metastases in the lungs. Doctors may treat these secondary tumors by surgically removing part of the liver or lungs, or by performing cryosurgery--a treatment in which liquid nitrogen is applied to the tumor to freeze and kill malignant cells. Depending on the case, doctors may also recommend surgical removal of the primary tumor in the colon along with anastamosis--a procedure in which the healthy ends of the colon are connected in order to bypass the tumor.
Radiofrequency Ablation
Radiofrequency ablation is an alternate procedure available for patients who cannot undergo traditional surgery or cryosurgery, according to the Memorial Sloan Kettering Cancer Center. During the procedure, the surgeon delivers intense heat to a localized area of malignant tissue using a special needle, in turn killing the tumor cells. The advantage of this procedure is that the tumor can be destroyed without having to be surgically removed from the body. Though more extensive research is needed, findings as of 2010 suggest that radio frequency ablation is effective and safe in treating both liver and lung metastases in some patients.
Radiation and Chemotherapy
Radiation therapy--the use of high-energy waves to kill tumor cells--and chemotherapy--the use of drugs to kill cancer cells--serve as palliative treatment options that may help to stall the spread of the cancer, reduce symptoms and improve quality of life for some with advanced colon cancer.
According to OncologyChannel.com, individuals with advanced colon cancer may receive one or more chemotherapy drugs alone or in conjunction with radiation or other medications. For example, doctors may treat those with metastatic disease with a combination of the chemotherapy agents leucovorin, 5-fluorouracil (5-FU) and irinotecan. Floxuridine may help to treat patients whose colon cancer has spread to the liver. Physicians may also combine chemotherapy drugs with blocking agents--drugs that inhibit tumor cell reproduction--such as cetuximab. Immunotherapy--drug treatment designed to boost the immune system's ability to fight disease and chemotherapy side effects--with levamisole or bacilli Calmette-Guerin (BCG) may also be used in combination with chemotherapeutic agents.
Monoclonal Antibody Treatment
Ongoing research is looking into the effectiveness of monoclonal antibody treatment--therapy that involves the administration of synthetic proteins that can bind to tumor cells and/or carry other drugs straight to the tumor, according to the National Cancer Institute. Bevacizumab is another type of monoclonal antibody treatment that may help to prevent the formation of new blood vessels surrounding the tumor, thus blocking its growth.
According to OncologyChannel.com, panitumumab is the only monoclonal antibody treatment approved by the Food and Drug Administration (FDA) for treatment of metastatic colon cancer. This drug may be administered once every two weeks following chemotherapy.
Hepatic Chemoembolization
Hepatic chemoembolization is a type of treatment that may be appropriate for some patients with colon cancer that has metastasized to the liver. During the procedure, surgeons cut off blood supply to the tumor and administer anticancer drugs directly to malignant cells in the liver. By blocking the blood vessels into and out of the tumor, doctors can prevent the chemotherapy medication from leaving the tumor site, thus increasing the drug's potency, according to the National Cancer Institute. Ongoing research is examining whether this treatment is most effective alone or in combination with other treatments.
