What`s new in liver cancer research and treatment?
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.
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 also being made in treating chronic hepatitis.
Several new blood tests are being studied to see if they can pick up liver cancer earlier than using AFP and ultrasound.
Newer techniques are being developed to make both partial hepatectomy and liver transplants safer and more effective.
Adding other treatments to surgery
An active area of research uses adjuvant therapies – treatments given right after surgery – to try to reduce the chances that the cancer will return. Most of the studies so far using chemotherapy or chemoembolization after surgery have not shown that they help people live longer. But newer drugs, such as the targeted drug sorafenib (Nexavar), may prove to be more effective. Some promising results have also been seen with radioembolization, but these need to be confirmed in larger studies.
Doctors are also 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 targeted therapy, chemotherapy, ablation, embolization, and radiation therapy. Early results have been promising but have only looked at small numbers of patients.
In laparoscopic surgery, several small incisions are made in the abdomen, and special long, thin surgical 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 a quicker recovery.
At this time, laparoscopic surgery is still considered experimental 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.
Determining recurrence risk after surgery
After a partial hepatectomy, one of the biggest concerns is that the cancer might come back (recur). Knowing someone's risk for recurrence after surgery might give doctors a better idea of how best to follow up with them, and may someday help determine who needs additional treatment to lower this risk.
Researchers may have found a way to do this by testing the cells in the surgery sample. In a recent study, they looked at the pattern of genes in liver cells near the tumor (not the tumor cells themselves) and were able to predict which patients were at higher risk for recurrence. This is an early finding that will need to be confirmed in other studies before it is widely used.
Only a small portion of patients with liver cancer may be candidates for a liver transplant at this time because of the strict criteria they need to meet (based mainly on the size and number of tumors). Some doctors are now looking to see if these criteria can be expanded, so that people who are otherwise healthy but have slightly larger tumors might also be eligible.
A major problem for patients needing a transplant is the lack of an available liver. Even for people who are eligible, there can be a long wait before a liver becomes available. Doctors are looking at using other treatments, such as ablation, to help keep the cancer in check until a new liver is available.
The main problem with using radiation therapy against liver cancer is that it also damages healthy liver tissue. Researchers are now working on ways to focus radiation therapy more narrowly on the cancer, sparing the nearby normal liver tissue. Several new approaches to radiation therapy are being tried, including stereotactic body radiation therapy. Radiosensitizers (drugs that make cancers more vulnerable to radiation) are also being studied.
New drugs are being developed that work differently from standard chemotherapy drugs. These newer drugs target specific parts of cancer cells or their surrounding environments.
Tumor blood vessels are the target of several newer drugs. Liver tumors need new blood vessels to grow beyond a certain size. The drug sorafenib (Nexavar®), which is already used for some liver cancers that can't be removed surgically, works in part by hindering new blood vessel growth. This drug is now being studied for use earlier in the course of the disease, such as after surgery or trans-arterial chemoembolization (TACE). Researchers are also studying whether combining it with chemotherapy or with other targeted drugs, such as erlotinib (Tarceva®), may make it more effective.
Brivanib is another targeted drug that works, at least in part, by slowing the growth of tumor blood vessels. It has shown promise in early studies and is now being tested in larger clinical trials.
Bevacizumab (Avastin®) also works to block new blood vessel growth. It has shown promising results against liver cancer both alone and in combination with the drug erlotinib in early studies, although more research is needed.
Other new drugs have different targets. For example, the drug erlotinib, which targets a protein called EGFR on cancer cells, has shown some benefit in people with advanced liver cancer in early studies. Several other targeted drugs are now being studied as well.
New forms of systemic and regional chemotherapy combined with other treatments are being tested in clinical trials. A small number of tumors respond to chemotherapy, although it has not yet been shown to prolong survival.
Newer chemotherapy drugs, such as oxaliplatin, capecitabine, gemcitabine, and docetaxel, are being tested against liver cancer in clinical trials. The drug oxaliplatin has shown promising results in early studies when given in combination with doxorubicin and also when given with gemcitabine and the targeted therapy drug cetuximab (Erbitux®).
A newer approach to treatment is the use of a virus known as JX-594. This is the same virus that was used to make the smallpox vaccine, but it has been altered in the lab so that it mainly infects cancer cells and not normal cells. It is injected into the blood and enters the cancer cells, where it causes them to die or to make proteins that result in them being attacked by the body’s immune system.
Early results against advanced liver cancer have been promising, even in patients who have already had other treatments, and larger studies of this treatment are now being done.
Last Medical Review: 06/21/2012
Last Revised: 01/18/2013