Several treatment options are available for patients with liver metastases, depending on the location of the primary cancer, the number and size of tumors, and the patient's general health. Most but not all liver metastases begin in the colon and spread to the liver.
Memorial Sloan-Kettering physicians specialize in the following treatment approaches, which are often used in combination:
Surgery to remove liver tumors (surgical resection) — often in combination with chemotherapy — is the most effective treatment for patients with liver metastases from colorectal cancer that are limited in size and number. Studies suggest that up to 50 percent of patients who undergo surgery to remove colorectal liver metastases survive for at least five years. (1) A study of patients treated at Memorial Sloan-Kettering — including those with more advanced disease — found that most of the patients who were disease-free five years after surgery were cured (did not experience a recurrence of their tumors more than ten years later). (2)
Despite its effectiveness, liver surgery is a challenging procedure that requires a team of experienced doctors who focus exclusively on treating patients with liver tumors. Many of the major blood vessels running to and from the heart pass behind or through the liver, essentially connecting these organs. In addition, the liver can tear easily and bleeds profusely when injured. Each year, surgeons at Memorial Sloan-Kettering treat more than 500 patients with liver metastases. Our doctors have developed and refined several techniques to improve the safety and effectiveness of surgery to remove liver metastases:
- When possible, our surgeons perform surgery to remove primary colorectal tumors and liver metastases during the same operation, rather than during two separate procedures. This combined approach to surgery has been shown (3) to significantly reduce the number of complications and recovery time for patients.
- Our surgeons have refined techniques that minimize blood loss and the need for transfusions during surgery.
- To further improve the chance of a good surgical outcome, interventional radiologists at Memorial Sloan-Kettering may perform a preoperative procedure called portal vein embolization. This procedure takes advantage of the liver's capacity to regenerate (including associated blood vessels) and its dual blood supply. Interventional radiologists redirect the blood supply to the healthy portion of the liver to stimulate cell growth before surgery. This technique improves recovery from liver resection by increasing the size of the liver that will remain after surgery.
- When possible, our doctors also use liver-sparing surgical techniques that leave more of the healthy liver intact, reducing the need for regeneration and the possibility of complications.
When possible and appropriate, Memorial Sloan-Kettering surgeons use minimally invasive laparoscopic surgery to remove liver tumors. Having laparoscopic surgery can significantly reduce patient recovery time compared with traditional surgery. In this procedure, surgeons insert a thin, lighted tube with a camera on its tip through a tiny incision in the patient's abdomen. Special surgical instruments are guided through the laparoscope to remove tumors or, in selected cases, part of the liver.
Many patients are not eligible for surgical removal (resection) of liver tumors because their cancer is too advanced. Image-guided therapies, which use imaging techniques such as CT, ultrasound, x-ray, and MRI to guide the delivery of treatments directly to the tumor site, offer an effective way to control, rather than cure, cancer. In addition, image-guided therapies can be used to enhance the effectiveness of other treatments, such as surgery.
Image-guided therapies are either delivered by a needle that is placed in the tumor to destroy tumor cells (ablation) or through a specially designed tube (catheter) that is threaded into the artery that supplies blood to the tumor. Image-guided therapies may be used alone, with other minimally invasive therapies, prior to or during surgery, or in combination with chemotherapy. In most cases, these procedures are performed by interventional radiologists on an outpatient basis or with a short hospital stay. Because image-guided therapies are targeted directly to the tumor, they kill cancer cells while sparing healthy liver tissue.
In thermal ablation, heat or cold is used to destroy liver metastases. There are currently three types of thermal ablation, including radiofrequency ablation, which uses radiowaves to superheat the tumor; microwave ablation, which uses microwaves to heat tumor cells; and cryoablation, which freezes the tumor. Doctors prescribe heat or cold depending on the size, location, and shape of the tumor.
Increasingly, ablation is performed by our surgeons in combination with liver surgery to remove tumors that may be considered inoperable at other hospitals, such as metastases that occur on both sides of the liver. Ablation also may be used to reduce the risk of recurrence for patients with liver metastases that cannot be completely removed with surgery alone. In addition, ablation may prolong survival for patients with recurrent metastases who were previously treated with surgery and chemotherapy. Ablation may be selected in place of surgery for patients who are too sick to undergo a surgical procedure.
Ablation often can be performed with minimally invasive techniques by our interventional radiologists, who deliver ablative therapies percutaneously (with a specially designed needle that is inserted through the skin). In addition, our surgeons may use a laparoscope (described above) to deliver ablative therapies. In some cases, ablative therapies may be delivered through a catheter with techniques called embolization or radioembolization (discussed below).
Memorial Sloan-Kettering is conducting a study supported by the NIH to help predict patients' response to treatment following ablation of colorectal liver metastases.
Radioembolization has recently been approved by the FDA to treat selected patients with colorectal liver metastases. In this technique, a catheter is placed into the hepatic artery, which supplies blood to the tumor. An interventional radiologist first injects dye into the catheter to identify the location of the tumor. Specially designed beads containing radioactive material are then inserted into the catheter, delivering a therapeutic dose of radiation to the tumor while sparing the healthy portion of the liver and other parts of the body.
Memorial Sloan-Kettering is conducting a clinical trial to study radioembolization in patients with colon cancer who did not respond to initial treatment with chemotherapy.
In recent years, the use of more effective chemotherapy drugs such as oxaliplatin and irinotecan has contributed to significant improvements in survival for patients with liver metastases. Medical oncologists at Memorial Sloan-Kettering use chemotherapy to reduce the risk of tumor recurrence following surgery (adjuvant therapy) and also to help shrink tumors prior to surgery (neoadjuvant therapy). Chemotherapy may be delivered systemically (throughout the body) through intravenous infusion or directly to the affected region with a procedure called hepatic arterial infusion.
Hepatic Arterial Infusion (HAI) Chemotherapy
Memorial Sloan-Kettering has significant experience with the use of HAI chemotherapy. This chemotherapy technique delivers a high dose of chemotherapy drugs into the hepatic artery — the main source of blood and nutrients for liver tumors — through a tiny pump implanted under the skin in the lower abdomen. Additional chemotherapy medicine is injected into the pump, as needed, on an outpatient basis.
HAI chemotherapy may be given alone or in combination with systemic chemotherapy as adjuvant therapy or neoadjuvant therapy. Our doctors have found that HAI chemotherapy prolongs survival for some patients following surgery. In addition, because HAI chemotherapy is delivered regionally (only to the tumor site), it causes fewer toxic side effects and has been associated with better physical functioning than systemic chemotherapy.
In a number of patients who cannot have liver metastases removed because of their number, size, or location, HAI plus systemic therapy can reduce tumors so that resection can become possible.
Chemotherapy as a Bridge to Surgery
Increasingly, doctors are using chemotherapy drugs to shrink tumors in patients with a variety of metastatic cancers. As a result, many patients with tumors that were once considered inoperable may safely undergo surgery - increasing the chance of a cure. Doctors at Memorial Sloan-Kettering routinely use systemic or regional chemotherapy as a bridge to surgery in patients with colorectal liver metastases. Studies have shown that nearly one-third of patients with “initially unresectable” colorectal liver metastases who undergo surgery following chemotherapy survive beyond five years, increasing the chance of a cure.
Investigational Approaches to Chemotherapy
At Memorial Sloan-Kettering, our investigators are constantly evaluating new chemotherapy combinations that may improve the standard of care for patients with liver metastases. These investigational therapies are sometimes offered to eligible patients through our clinical trials.
General side effects, such as fatigue, nausea, and diarrhea, can be expected from any chemotherapy drug or combination of drugs, but side effects vary from patient to patient. Talk to your doctor about possible side effects before starting a chemotherapy treatment regimen.
Unlike chemotherapy drugs, which kill both cancer cells and healthy cells, biologic therapy offers a targeted approach to fighting cancer by stopping the replication of tumor cells and/or disrupting a tumor's blood supply. Biologic therapy is now used in combination with many chemotherapy drugs to improve the effectiveness of treatment. Biologic therapies include:
These drugs, used in combination with chemotherapy, stop the growth of blood vessels that nourish tumors. Anti-angiogenesis drugs such as bevacuzimab (Avastin®) may be given before or after surgery.
Epidermal Growth Factor Receptor (EGFR) Inhibitors
These drugs block epidermal growth factor receptor, a protein that may contribute to the progression of colorectal cancer. EGFR therapy with cetuximab or panitumumab is not effective for patients with a specific type of mutation in a gene called KRAS. Laboratory tests are now used to screen patients with liver metastases for this mutation and determine whether EGFR therapy is appropriate. In addition, clinical studies are underway to evaluate drugs, including novel therapies, that may be effective in treating tumors with this mutation.
Radiation therapy is used in selected cases to help control liver metastases that cannot be surgically removed or are too large to be treated effectively with ablation. Our radiation oncologists work with specialists from our medical physics department to develop an individualized treatment plan using the latest techniques to deliver radiation directly to the tumor and minimize damage to healthy liver tissue and surrounding organs.
One technique, intensity-modulated radiation therapy (IMRT), uses radiation beams of varying intensity that are molded to the shape of the tumor. Using highly sophisticated computer software and 3-D images from CT scans, radiation is focused on cancerous tissue with greater precision than conventional radiation therapy.
Another approach, known as stereotactic body radiation therapy, uses a highly focused radiation field to deliver greater doses of radiation in fewer treatments. Stereotactic body radiation therapy combines IMRT and image-guided radiotherapy (IGRT), which uses tiny gold seeds that are implanted into the tumor to act as a visual guide during imaging. A CT scan reveals the exact location of the seeds, helping guide radiation directly to the tumor site.
Because tumors and organs in the abdomen shift during breathing, precise delivery of radiation therapy to cancerous tissue can be difficult. Doctors at Memorial Sloan-Kettering use motion-management techniques to target liver metastases while sparing healthy tissue. Respiratory gating is a motion-management technique that delivers radiation only at certain points during a patient's breathing cycle, when mobile tumors are in a specific position. In some cases, the radiologist will employ a technique called abdominal compression, which uses a specially designed compression belt to apply pressure to the abdomen to help minimize tumor movement during treatment. Our researchers are also evaluating the use of anesthesia to minimize respiratory motion during radiation treatments.