New research shows increasing disparity in mortality among candidates with and without hepatocellular carcinoma (HCC) who are on the waiting list for liver transplantation. The study available in the April issue of Liver Transplantation, a journal published by Wiley-Blackwell on behalf of the American Association for the Study of Liver Diseases, found that liver cancer patients are less likely to die on the wait list than non-HCC candidates, prompting transplantation specialists to suggest a reevaluation of current allotment criteria for those with HCC.
In 2002, the United Network for Organ Sharing (UNOS) implemented the Model for End Stage Liver Disease (MELD) scoring system to prioritize candidates on the waiting list for liver transplantation in the U.S. While MELD accurately predicts 90-day waitlist mortality, there are some candidates with extensive disease symptoms, such as those with HCC, who need additional prioritizing criteria to assess clinical risk. These candidates receive MELD exception points, of which HCC patients on the wait list could gain 22 points based on increased mortality risk, meaning HCC patients may be transplanted before other patients at greater risk of death.
“With the scarcity of available livers for transplantation, it is vital that allocation criteria ensure those candidates at greatest mortality risk are first to receive a life-saving organ,” said Dr. David Goldberg with the University of Pennsylvania and lead author of the current study. “Our study investigated appropriate designation of exception points for transplant candidates with HCC, comparing mortality risk to those with similar MELD scores, but without liver cancer.”
The team analyzed data from the Organ Procurement and Transplantation Network (OPTN) UNOS database, including candidates eighteen years of age and older who were on the waiting list for liver transplantation between January 2005 and May 2009. The HCC group was comprised of 6,246 candidates who received exception points for stage two (T2) liver cancer. These candidates were more likely to be older, male and Caucasian or Asian compared to those without liver cancer. In the non-HCC cohort, candidates were categorized by MELD score with 2,564 candidates with a score of 21-23; 4,655 with 24-26; and 2,737 with MELD 27-29.
Analysis shows that within 90 days of listing 4.2% of HCC candidates were removed from the wait list for death or clinical deterioration compared to 11% of non-HCC candidates with MELD scores 21-23. For HCC candidates with 25 exception points (3-6 months wait-time) versus non-HCC candidates with MELD scores 24-26, close to 5% and 17% were removed from the waiting list, respectively. Of the HCC candidates with 28 exception points (6-9 months wait-time) 3% were removed for death or clinical deterioration compared to 24% of non-HCC candidates with MELD scores of 27-29.
Liver Cancer Facts
Liver cancer, or hepatocellular carcinoma, is a disease in which malignant cells grow in the tissue of the liver, one of the largest organs in the body.
The liver is an essential organ that people cannot live without. It processes and stores many of the nutrients absorbed from the intestine, causes the secretion of bile that helps in the digestion of food, and produces some of the clotting factors that keep you from bleeding too much when cut or injured. The liver gets most of its supply of blood from the hepatic portal vein, which carries nutrient-rich blood from the intestines; the rest comes from the hepatic artery, which supplies the liver with blood that is rich in oxygen.
Because the liver is made up of several different types of cells, several types of tumors can form in the liver; some are cancerous and some are benign.
Roughly 75 percent of primary liver cancers begin in hepatocytes (liver cells). Hepatocellular carcinoma most commonly occurs in people whose livers have been damaged. This damage is usually caused by alcohol abuse, by chronic infection with the hepatitis B or hepatitis C virus, or cirrhosis, from food contaminants, or from metabolic diseases.
Researchers determined that over time the risk of waitlist mortality or clinical decline was unchanged for HCC candidates, but increased significantly for non-HCC candidates. Dr. Goldberg concludes, “Our data suggest HCC candidates have substantially lower odds of waitlist removal for death or deterioration than non-HCC candidates, and strongly indicates that exception points currently allotted for HCC should be lowered.”
Liver Cancer Symptoms
Unless a person has a preexisting liver condition, such as cirrhosis, which would cause the symptoms of liver cancer to appear more quickly and be more intense, they may not realize the symptoms are an indicator of a serious medical condition. It is for this reason that many people are not diagnosed until the liver cancer is in the advanced stage. Some of the symptoms include feeling weak or tired, jaundice (yellowing of the skin), loss of appetite and vomiting (which could lead to anorexia), feeling bloated and a dull pain that begins in the upper abdomen, sometimes extending around to the back. This may happen as the tumor grows larger.
Liver Cancer Stages
Before the doctor can devise a treatment plan, he must first determine what stage liver cancer the patient is in. There are five stages of cancer; however, they are grouped together into three treatment stages. The first, localized resectable, is used to describe a patient whose cancer is only in the liver, having not yet spread, and that can be removed completely by surgery. The second, localized and locally advanced unresectable, is used to describe a patient whose cancer is isolated to the liver, has not yet spread, but cannot be completely removed by surgery alone. The last is the advanced stage, and this is used to describe a patient whose liver cancer has spread through her body.