Metastatic rectal cancer is cancer arising from the rectum that has spread beyond the rectum, usually to the liver, lungs, ovaries and elsewhere in the abdominal cavity. According to the American Cancer Society (ACS), treatment options at this stage depend largely on the extent of the cancer's spread.
Surgery
According to the National Cancer Institute (NCI), surgery can be used to remove isolated metastasis in the liver, lungs or ovaries. Resection of the primary tumor in the rectum and/or a recto-anal anastomosis, involving a bypass surgery to join the colon directly to the anus, are all surgical options mentioned by the ACS. A colostomy, an opening on the wall of the abdomen to bypass any obstruction in the rectum and drain the colon, is another surgical option that may be used in metastatic rectal cancer.
Chemotherapy
Drugs that destroy cancer cells are used in chemotherapy of metastatic rectal cancer. The drugs are given intravenously, or into the liver artery as a hepatic artery infusion in the case of liver metastasis.
According to the NCI, the drugs used in chemotherapy for metastatic rectal cancer are 5-flourouracil with leucovorin, capecitabine, irinotecan and oxaliplatin. These are used as single agents or in combinations. Chemotherapy can be used before surgery to shrink cancers and metastases to make surgical removal possible or easier. It may also be given after surgery to increase the effectiveness of treatment and reduce chances of recurrence. Chemotherapy can also be combined with radiation therapy, according to the ACS.
Targeted Therapy
Targeted therapy is the use of drugs designed to attack cancer-specific structures and functions. According to the ACS, the drugs used in targeted therapy for metastatic rectal cancer are bevacizumab, cetuximab and panitumumab. Targeted therapy is sometimes combined with chemotherapy or given alone.
Radiation Therapy
Radiation therapy, according to the ACS, can be used in metastatic rectal cancer before surgery in an attempt to shrink the tumor and make it easier to remove. Radiation therapy can also be used to prevent recurrence after removal of metastasis. It can be combined with chemotherapy or used alone.
In widespread metastasis where surgical removal is not possible, radiation therapy can be used as a palliative treatment to relieve pain and discomfort.
Other Treatments
According to the ACS, other non-surgical options for treating liver metastasis include cryosurgery, radiofrequency ablation and photocoagulation. Painful symptoms can also be treated with morphine and other strong analgesics. Multivitamins and food supplements are other complementary treatments that are used in metastatic rectal cancer.
