Metastatic Colon Cancer to the Liver
Background
In the United States, there are 140,000 new cases of colon cancer diagnosed each year, making it one of the most frequently encountered cancers. In approximately 60 percent of patients diagnosed with colon cancer the cancer will eventually spread to the liver (liver metastases). Thus, metastatic colon cancer is 10 to 20 times more common than primary cancers of the liver (HCC or cholangiocarcinoma) for patients in the United States. For certain populations in Africa and Asia, this ratio is lower due to the high incidence of HCC in those areas.
Diagnosis
Metastatic colon cancer to the liver is usually identified in patients with a prior history of primary colon cancer who are found on surveillance screening to have an elevated CEA blood test or abnormal mass in the liver detected by U/S, CT, or MRI scan. Liver biopsy is often done to confirm that the mass represents metastatic colon cancer. Patients may also present with abdominal pain or abnormal liver function tests, which leads to the discovery of the tumor.
Treatment Options
The treatment of metastatic colon cancer depends on the extent of the disease. A full evaluation is performed consisting of blood tests and a CT scan of the chest, abdomen, and pelvis (if not already done). If the tumor is confined to the liver with no signs of extra-hepatic disease, then the first choice for treatment is surgical resection, which gives the patient the best chance for cure or long-term survival. Occasionally, a large tumor in one lobe of the liver can be surgically removed, and a smaller tumor in the remaining lobe can be treated by thermal destruction with radiofrequency ablation (RFA) during the same operation.
The decision regarding postoperative adjuvant (follow-up) systemic or regional chemotherapy is made by the patient’s medical oncologist after discussion with the patient and the surgical team from the UPMC Liver Cancer Center.
Other treatment options include radiofrequency ablation (RFA) of localized tumors, regional perfusion of the liver with chemotherapy delivered via an implanted hepatic artery infusion pump, internal radiation with yttrium90 radioactive glass beads (sirspheres), or systemic chemotherapy. For unresectable colon cancer metastases confined to the liver, the UPMC Liver Cancer Center just completed a gene therapy clinical trial in which a novel virus was injected into the liver, followed by regional chemotherapy to enhance the tumor destruction. A follow-up protocol is being planned.