Because there are only a few effective ways to prevent or treat liver cancer at this time, there is always a great deal of research going on in the area of liver cancer. Scientists are looking for causes and ways to prevent liver cancer, and doctors are working to improve treatments.

Prevention

The most effective way to reduce the worldwide burden of liver cancer is to prevent it from happening in the first place. Some scientists believe that vaccinations and improved treatments for hepatitis could prevent about half of liver cancer cases worldwide. Researchers are studying ways to prevent or treat hepatitis infections before they cause liver cancers. Research into developing a vaccine to prevent hepatitis C is ongoing. Progress is being made in treating chronic hepatitis with drugs that boost the patient's immune system.

Screening

Several new blood tests are being studied to see if they can pick up liver cancer earlier than the test already being used. So far, none of these has proved more helpful than the ones already in use.

Surgery

Newer techniques are being developed to make both partial hepatectomy and liver transplantation safer and more effective.

Doctors are studying ways to make more liver cancers resectable by trying to shrink them before surgery. Studies are now looking at different types of neoadjuvant therapies (therapies given before surgery), including chemotherapy, immunotherapy, embolization, and radiation therapy. Early results have been promising but have only looked at small numbers of patients.

Another active area of research uses adjuvant therapies - those given right after surgery to try to reduce the chances that the cancer will return. Unfortunately, most of the studies involving adjuvant chemotherapy or chemoembolization have not shown that they prolong survival times. Some promising results have been seen with radioembolization (see next section), but these need to be confirmed in larger studies.

Doctors are also beginning to study a technique called laparoscopic surgery. In this procedure, several small incisions are made in the abdomen, through which specially designed instruments are inserted to view and cut out the diseased portion of the liver. It does not require a large incision in the abdomen, which means there is less blood loss, less pain after surgery, and quicker recovery. At this time, laparoscopy is still considered an experimental form of treatment for liver cancer. It is being studied mainly in patients with small tumors in certain parts of the liver that can be easily reached through the laparoscope.

Radiation Therapy

The major problem with using radiation therapy against liver cancer is that it also damages healthy liver tissue. Researchers are now working on ways to deliver radiation therapy only to the cancer, sparing the normal tissue. Several new approaches to radiation therapy are being tried, including using radiosensitizers (drugs that make cancers more vulnerable to radiation).

Radioembolization is another exciting area of research. This involves infusing radioactive substances directly into the hepatic artery, from which they can target liver tumors more precisely.

One technique uses tiny glass beads (called microspheres) that are attached to a radioactive element (yttrium-90). Once infused, these beads lodge in the blood vessels near the tumor, where they give off radioactivity for a short while. At least one form of these beads, known as TheraSphere, has been approved for use by the FDA and is now being used in several cancer treatment centers. Long-term data on its effectiveness are not yet available.

Another technique uses oil that contains radioactive iodine-131. This substance, known as I-131 Lipiodol, is also infused directly into the hepatic artery. One clinical trial found this type of radioembolization may be effective but more studies are needed to confirm this. It is not available in the United States at this time.

Chemotherapy

New forms of systemic and regional chemotherapy combined with other treatments are being tested in clinical trials. A small portion of tumors respond to chemotherapy, although it has not yet been shown to prolong survival.

Newer chemotherapy agents, such as oxaliplatin, gemcitabine, and docetaxel, are now being tested against liver cancer in clinical trials, as are more targeted therapies such as erlotinib (Tarceva) and thalidomide.

Hepatic artery infusion (HAI): One way researchers are attempting to improve on the effectiveness of chemotherapy is to deliver it directly into the hepatic artery, which supplies most tumors. The healthy liver then removes most of the remaining drug before it can reach the rest of the body. The drugs most commonly used include floxuridine (FUDR), cisplatin, mitomycin C, and doxorubicin.

While early studies have found that HAI is effective in shrinking a number of tumors, more research is still needed. This technique may not be useful in all cases because it often requires surgery to insert a catheter into the hepatic artery, an operation that many liver cancer patients may not tolerate well.

Targeted Therapy

New drugs are being developed that target specific points on the cancer cell and kill it. One of these, called erlotinib (Tarceva), has shown some benefit in people with advanced liver cancer. Several other targeted drugs are now under study.

Gene Therapy

Scientists are learning more about many of the genes that are damaged when normal liver cells become cancerous. The hope is to develop gene therapies aimed at replacing these defective DNA sequences. The p53 gene is a tumor suppressor gene that is often altered in liver cancers. In normal liver cells, it prevents excessive growth, helps cells repair damage to their DNA, and promotes the death of cells when DNA damage becomes too much to be repaired. Restoring normal p53 DNA to liver cancer cells might suppress tumor growth and cause the cancer cells to die. Clinical trials are in progress to study the effectiveness of this type of therapy, including possible short and long-term side effects.