Intrahepatic Pump Therapy for Metastatic Colon/Rectal Cancer
Rationale
Hepatic metastases from colorectal cancer can be treated by administering the chemotherapy directly into the liver. This allows a much higher concentration of the chemotherapy where it is needed, i.e. on the tumor itself, with a decrease in the systemic side effects of the chemotherapy. Particularly for colon cancer metastases to the liver, there is evidence for a higher response rate in patients treated with the chemotherapy drug FUDR (fluorouracil deoxyribose) delivered by an implanted hepatic artery pump.
There are two primary indications for this type of treatment:
- For patients who have unresectable metastatic colon cancer to the liver who have failed standard chemotherapy.
- For patients who have had cancer resected or removed from the liver, but who are at high risk for developing further cancers in the liver because of the likelihood of remaining microscopic cancer cells within the liver. Recent publications have shown that patients who have this form of adjuvant chemotherapy after surgical resection of tumor metastases from the liver, are much less likely to get re-recurrence of the liver metastases than patients who are not treated this way.
The procedure (see diagram)
An abdominal incision is made under the right ribs and a small metal pump (about 3 inches in size) is placed in a subcutaneous pocket (under the skin). It has thin tubing that goes into a side branch of the hepatic (liver) artery and delivers chemotherapy (or saline) directly into the liver. At the time of surgery, the pump is filled with heparinized saline (so the tubing does not clot off). The operation lasts about two hours and the patient usually stays in the hospital for three to four days.
Two weeks after the surgery, the pump is refilled in your medical oncologist’s office and the chemotherapy begins. The pump holds two weeks worth of chemotherapy and delivers 1 milliliter per day slowly into the liver. The pump is re-filled once every two weeks. The refill is usually painless and only takes 10 minutes. In general, the chemotherapy is given for a two week period, followed by two weeks of rest with heparinized saline (hence, two weeks on therapy, alternating with two weeks off therapy). The length of time that a patient is treated with chemotherapy is determined by your team of doctors.