Chemoembolization is a minimally invasive treatment for liver cancer that can be used when there is too much tumor to treat with radiofrequency ablation (RFA), when the tumor is in a location that cannot be treated with RFA, or in combination with RFA or other treatments.
Chemoembolization delivers a high dose of cancer-killing drug (chemotherapy) directly to the organ while depriving the tumor of its blood supply by blocking, or embolizing, the arteries feeding the tumor. Using imaging for guidance, the interventional radiologist threads a tiny catheter up the femoral artery in the groin into the blood vessels supplying the liver tumor. The embolic agents keep the chemotherapy drug in the tumor by blocking the flow to other areas of the body. This allows for a higher dose of chemotherapy drug to be used, because less of the drug is able to circulate to the healthy cells in the body. Chemoembolization usually involves a hospital stay of two to four days. Patients typically have lower than normal energy levels for about a month afterwards.
Chemoembolization is a palliative, not a curative, treatment (relieving pain or alleviating a problem without dealing with the underlying cause). It can be extremely effective in treating primary liver cancers, especially when combined with other therapies. Chemoembolization has shown promising early results with some types of metastatic tumors. Although the individual materials used in this treatment are FDA approved, the treatment itself is not approved for intra-arterial therapy of liver tumors.
Minimally Invasive Treatments Help Cancer Patients Extend Life and Improve Quality
Surgical removal of liver tumors offers the best chance for a cure. Unfortunately, liver tumors are often inoperable because the tumor may be too large, or has grown into major blood vessels or other vital structures. Sometimes, many small tumors are spread throughout the liver, making surgery too risky or impractical. Surgical removal is not possible for more than two-thirds of primary liver cancer patients and 90 percent of patients with secondary liver cancer.
Historically, chemotherapy drugs have been generally ineffective at curing liver cancer.
Primary liver cancer:
- About 18,500 cases of primary liver cancer are diagnosed each year. The most common form is hepatocellular carcinoma (HCC). This is a tumor that begins in the main cells of the liver (hepatocytes). Primary liver cancer is twice as common in men as in women.
- HCC most frequently occurs in those who have a form of liver disease called cirrhosis. Cirrhosis occurs when the liver becomes diseased and develops scarring, usually over a period of years. The liver attempts to repair, or regenerate itself. This process can lead to the formation of tumors. In the United States, the most common causes of cirrhosis are alcohol abuse and chronic infection with the liver virus hepatitis B or C.
- The incidence of primary hepatocellular carcinoma is on the rise worldwide, because of the increase of hepatitis C.
Metastatic liver cancer
Cancer may spread from any part of the body to the liver. There the cancer cells may grow for months or years before they are detected. One of the most common sources of metastatic liver cancer is from tumors of the colon and rectum. About 140,000 people in the United States are diagnosed with colon cancer each year, and roughly half of these patients will develop tumors in their liver at some time. About one in 10 of these patients will have a chance for a cure by having the liver tumors removed surgically.
Patients with other types of cancer also are at risk for liver cancer. The liver serves as a way-station for cancer cells that circulate through the bloodstream. These cells may grow and form tumors in the liver. It is estimated that as many as 70 percent of all people with uncontrolled cancer will eventually develop secondary liver tumors, or metastases (tumors formed by primary cancer cells that have spread from other cancer sites).
Liver Cancer Diagnosis
There are a number of tests that can help in the diagnosis of cancer, including blood tests, physical examination and a variety of imaging techniques including X-rays (e.g., chest X-rays and mammograms); computed tomography (CT); magnetic resonance (MR) and ultrasound. Usually, however, the final diagnosis cannot be made until a biopsy is performed. In a biopsy, a sample of tissue from the tumor or other abnormality is obtained and examined by a pathologist. By examining the biopsy sample, pathologists and other experts also can determine what kind of cancer is present and whether it is likely to be fast or slow growing. This information is important in deciding the best type of treatment. Open surgery is sometimes performed to obtain a tissue sample for biopsy. But in most cases, tissue samples can be obtained without open surgery with interventional radiology techniques.
Needle biopsy, also called image-guided biopsy, is usually performed using a moving X-ray technique (fluoroscopy) computed tomography (CT), ultrasound or magnetic resonance (MR) to guide the procedure. In many cases, needle biopsies are performed with the aid of equipment that creates a computer-generated image and allows radiologists to see an area inside the body from various angles. This “stereotactic” equipment helps them pinpoint the exact location of the abnormal tissue.
Needle biopsy is typically an outpatient procedure with very infrequent complications; less than 1 percent of patients develop bleeding or infection. In about 90 percent of patients, needle biopsy provides enough tissue for the pathologist to determine the cause of the abnormality.
Advantages of needle biopsy include:
- With image guidance, the abnormality can be biopsied while important nearby structures such as blood vessels and vital organs can be seen and avoided.
- The patient is spared the pain, scarring and complications associated with open surgery.
- Recovery times are usually shorter and patients can more quickly resume normal activities.
An X-ray of a needle inserted into the lung to obtain a sample for biopsy.
Large core needle biopsy. In this technique, a special needle is used that enables the radiologist to obtain a larger biopsy sample. This technique is often used to obtain tissue samples from lumps or other abnormalities in the breast that are detected by physical examination or on mammograms or other imaging scans. Because approximately 80 percent of all breast abnormalities turn out not to be cancer, this technique is often preferred by women and their physicians because it:
- is less painful and requires less recovery time than open surgical biopsy, and
- avoids the scarring and disfigurement that may result from open surgery.
A similar technique called fine needle aspiration can be used to withdraw cells from a suspected cancer. It also can diagnose fluids that have collected in the body. Sometimes, these fluid collections also may be drained through a catheter, such as when pockets of infection are diagnosed.
Many interventional radiology procedures for the diagnosis and treatment of cancer can be performed on an outpatient basis or during a short hospital stay. In many cases, the procedures:
- offer new cancer treatment options
- are less painful and debilitating for patients
- result in quicker recoveries
- have fewer side effects and complications.