Options for Treating Inoperable Liver Metastases from Colon Cancer
Nearly one third of patients diagnosed with colon cancer already have metastatic disease. colon cancer that has spread to the liver is classified as metastatic disease also called stage IV. The liver is the most common site for metastasis. If surgical resection of the metastases is not possible, and the lesion or lesions are considered inoperable, due to a variety of factors you may be deemed a good candidate for liver directed or targeted therapies. Liver directed therapies include ablation, embolization and internal radiation using yiitrium-90 microspheres. Liver directed treatments can be used alone or in combination with chemotherapy and/or biologic agents.
A variety of ablative therapies are now available; these include: Radiofrequency Ablation (RFA), Cryotherapy and Microwave Ablation (MA). These procedures are performed by a surgeon or interventional radiologists (IR) who specializes in oncology procedures. All of these techniques are applicable to patients that have a limited number of metastatic liver tumors.1 RFA, Cryotherapy and Microwave Ablation (MA) are considered beneficial for patients with unresectable liver-only disease who present with tumors less than or equal to 3-4 cm2.
- Radiofrequency Ablation (RFA) uses electrical energy to create heat in a tumor for a specific period of time. The result of this “super heating” is the death or destruction of the tumor. The procedure can be performed percutaneously, by inserting a needle through the skin under x-ray guidance, then placing a probe through the needle and positioning it in the liver tumor. The percutaneous procedure is usually performed by an interventional radiologist under local anesthesia. Alternatively, the procedure can be done laparoscopically, using a laparoscope that is inserted through a tiny incision in the abdomen. It may also be done as an open surgical procedure. The laparoscopic and open surgical procedures are performed by a surgeon. RFA is safe, well tolerated and an effective treatment for patients with inoperable metastatic liver tumors. RFA is most effective in liver lesions that are less than or equal to 3-4 centimetres in size.3
Side Effects: Many patients experience a low grade fever for a few days following the procedure. There is a very low risk of infection, bleeding and skin burn.
Recovery: If the percutaneous method is used then the patient will go home the same day. If a laparoscopic procedure is selected then the patient usually goes home the following day. An open surgical procedure requires that an incision be made in the abdomen, general anesthesia is needed and the recovery period will be longer.
- Cryotherapy or Cryosurgery uses super cooled nitrogen or argon gas to freeze liver lesions thereby destroying the tumor. Similar to RFA, the procedure can be performed percutaneously. In cryotherapy the doctor uses MRI or ultrasound to guide the probe and monitor the formation of an “ice ball” in the tumor and limiting damage to surrounding tissue. The procedure may also be performed by a surgeon using an open surgical procedure. Clinical and laboratory research suggest that hepatic cryotherapy is effective in patients with inoperable tumors, which are located in a difficult section of the liver (near large vessels). Like RFA, cryotherapy is most effective in liver lesions that are less than or equal to 3-4 centimetres in size.
Side Effects: Complications of cryotherapy may include bleeding, mild fever, increase in liver enzymes due to damage to the bile ducts, infection or abscess.
Recovery: If the percutaneous method is used, the patient will usually go home the same day. An open surgical procedure requires that an incision be made in the abdomen, general anesthesia is needed and the recovery period will be longer.
- Microwave Ablation (MA) is an ablative therapy that produces coagulation of soft tissue during a percutaneous, laparoscopic or open surgical procedure. Microwave ablation (MA) uses microwave energy and an antenna to cause coagulation of tissue by creating heat by friction and vibration of water molecules in the cells. The advantage of MA over other heating systems, such as RFA, is that the microwave technique is quicker and does not cause collateral damage and can be completed in 10 minutes.
Side Effects: Many patients experience a low grade fever and pain for a few days following the procedure. Major complications include liver abscess, bile duct injury, infections, bleeding and skin burn.
Recovery: If the percutaneous method is used the patient will usually go home the same day. If a laparoscopic procedure is selected then the patient often goes home the following day. An open surgical procedure requires that an incision be made in the abdomen, general anesthesia is used, and the recovery time will be longer.
Internal Radiation Therapy:
SIRT (Selective Internal Radiation Therapy) is a targeted radiation therapy that uses SIR-Spheres® microspheres to treat metastatic liver cancer.
During the procedure, an interventional radiologist makes a small puncture, usually into the femoral artery near the groin. A small flexible tube known as a catheter is then guided through the artery into the liver and millions of microscopic spheres (each about a third of the width of a human hair), are delivered directly into the tumor where they become trapped. The SIR-Spheres microspheres emit beta radiation for a period of about two weeks.
This targeted therapy delivers a dose of internal radiation up to 40 times higher than conventional external beam therapy. Normal liver tissue takes about 90 percent of its blood supply from the veins, while liver tumors receive about 90 percent of their blood supply from arteries. This allows SIR-Spheres microspheres to target the liver tumors with a tumor-killing dose of radiation via the hepatic artery, while sparing surrounding healthy liver tissue. Besides offering patients an effective treatment option to control the advancement of liver metastases, SIRT also helps patients maintain a good quality of life.
The procedure is performed in a hospital on an outpatient basis by highly trained interventional radiologists. SIR-Spheres microspheres are currently offered at more than 700 medical centers around the world, including more than 300 centers in the U.S
This treatment is indicated for patients with coloncancer that has spread to the liver and cannot be surgically removed. SIR-Spheres microspheres are the only fully FDA PMA approved microspheres for colon cancer that has metastasized to the liver.
Almost all treatments and drugs can produce unwanted side effects, but when properly administered, most side effects are typically mild and subside within several days. Some side effects following a SIRT procedure can be minor, making patients feel uncomfortable, but a small number can be serious. Every patient is different in how he or she reacts to a treatment. Many patients experience abdominal pain or tightness in their abdomen, nausea and loss of appetite which normally subsides within a week. Many patients also develop a mild fever that may last for up to a week and fatigue which may last for several weeks. As a precaution, specific medications are prescribed to control these symptoms.
In rare instances there is a possibility that a small number of microspheres may inadvertently reach other organs in the body, such as the gall bladder, stomach, intestine or pancreas. If SIR-Spheres microspheres reach these organs, they may cause inflammation of the gall bladder (cholecystitis), stomach (gastritis) or intestine (duodenitis). These complications are rare, but if one of these occurs, they will require additional treatment. Your treatment team will have received special training to minimize these risks and to prevent them from happening.
The treatment normally takes about 60 to 90 minutes. Patients will be sleepy during the procedure but able to communicate with the doctor and the team. Most patients return home four to six hours following treatment.
- Embolization therapy is performed by interventional radiologists in the radiology suite. It is a non-surgical procedure to treat inoperable metastatic liver tumors. Small particles or beads, ranging in size from 100 to 900 microns made of a biocompatible resin, are injected into selected vessels to block the blood flow feeding the tumors causing the tumor to shrink. Under local anesthesia, a small incision is made in the groin to access the femoral artery and a narrow guidewire is inserted. A delivery catheter is inserted over the wire and under x-ray guidance (angiography) the tip of the catheter is positioned so that the particles will be delivered to the tumor. Particles are injected until the embolization is complete and the artery is blocked. Over the following months, the embolized vessels will permanently shrink and the tumor will decrease in size. Embolization can be performed with bland particles (without drug added), or with drug added which is called TACE (Transarterial Chemoembolization). Cutting off the blood supply to the tumor allows for higher doses of chemotherapy to be delivered and remain in contact with the tumor, and preventing the chemotherapy reaching healthy tissue. TACE normally contains a mixture of bland particles and two to three chemotherapy agents. TACE may also be performed using different particles made of a biocompatible resin modified for the controlled loading and delivery of drug. These particles are called drug eluting beads (DC Bead or DEBIRI) . Drug eluding beads are mixed with one chemotherapy agent (Irinotecan)4 and contrast dye. The beads will absorb the chemotherapy agent and once injected into the tumor will slowly release the drug over days.
Side Effects: The side effects will differ depending upon the type of embolization used. The most common complications reported are pain, nausea and severe post embolization syndrome (fever, pain, extreme fatigue, nausea/vomiting), hepatic injury and liver abscess.
Recovery: Most patients can be discharged a few hours after the procedure. If post embolization syndrome occurs an overnight stay is normally required.
This information was compiled with the generous help of Laura Porter, MD, Medical Consultant and Patient Advocate for the Colon Cancer Alliance, as well as Desiree Gray, Director of Health Economics & Patient Advocate for Sirtex Medical, Inc.
- Stubbs RS et al. Aust NZ J Surg 2006;76(8):696–703.
- Tol J et al. N Engl J Med 2009;360:563–72.
- Stubbs RS et al. Aust NZ J Surg 2006;76(8):696–703.
- Note: Biocompatibles DC – DEBiRI bead is 510K approved in the US as a bland particle only