Liver Transplant Eligibility: A Guide for Liver Cancer Patients

Eligibility for a liver transplant is determined by a comprehensive evaluation process, ensuring the best possible outcomes for recipients. Liver transplant criteria include the Model for End-Stage Liver Disease (MELD) scoring system and the Milan criteria. Still, many centers allow for expanded criteria and tumor down-staging to increase access to liver transplant for a wider spectrum of patients. Not everyone may be a suitable candidate, and these guidelines focus on understanding the severity of liver disease and your overall health. While some patients may not initially be eligible, there are potential treatments available that can improve one’s eligibility.

To qualify for a liver transplant, patients must meet specific guidelines known as the Milan criteria. These are a set of liver transplant guidelines adopted in many countries. This set of criteria includes the following:

• Tumor size — A patient may be eligible if they have a single tumor smaller than 5 cm, or up to three tumors, each smaller than 3 cm.
• Vascular invasion — Patients must show no evidence of vascular invasion. Vascular invasion is associated with a higher risk of cancer recurrence post-transplant.
• Extrahepatic metastasis — Liver transplantation is not recommended for patients with extrahepatic metastasis. If the cancer has spread beyond the liver, the likelihood of a successful outcome is significantly reduced.

In addition to the Milan criteria, there are other factors that can affect a patient's eligibility for a liver transplant:

• Absence of alcohol or substance abuse — There is a high demand for liver transplants, and chronic alcohol consumption and substance abuse can lead to liver damage. Therefore, it is crucial for patients to demonstrate no signs of future abuse to ensure the best outcomes after transplantation.
• Good overall health or stable medical conditions — Patients who are medically unfit for surgery are typically not eligible for transplantation. The transplantation procedure and recovery are physically demanding, and patients must be stable enough to survive the surgery. Examples of medical conditions that may disqualify one from having a liver transplant include significant heart, lung, or other systemic diseases, or uncontrolled infections despite treatment like HIV infection with AIDS.

Ability to comply with post-transplant care — Patients who may face difficulties following the strict medical regimen necessary after a transplant, including lifelong immunosuppressive therapy, may not be suitable for a liver transplant. In this case, not following one’s medications could lead to organ rejection.

The Model for End-Stage Liver Disease (MELD) scores the severity of a patient’s liver disease. Doctors will calculate the MELD score to rank how urgently one needs a liver transplant. It is calculated through blood tests measuring

• Bilirubin — High levels indicate either liver dysfunction or bile duct obstruction, manifested by bile leakage into the bloodstream
• Creatinine — A measure of kidney function
• Blood clotting time — Assessed as International Normalized Ratio (INR)
• Serum sodium — Reflects the body’s fluid-salt balance

Transplant from deceased donors

A patient who meets the Milan criteria can be considered a candidate for liver transplant and be added to the national waiting list for livers from deceased donors.

Livers from deceased donors are prioritized for the sickest patients based on their MELD score. In addition to the MELD score, donor matching requires compatibility in

• Blood type
• Body size
• Geographical proximity

Transplant from living donors

Patients with low MELD scores may explore a living donor transplant. A friend or family member who is compatible in factors such as blood type and body size may volunteer to donate a portion of their liver. Living donors must undergo a thorough screening, including

• Medical evaluation of their overall health and fitness for surgery, and liver function
• Counseling to ensure they fully understand the risks involved and are psychologically prepared for the commitment

Given that transplants typically cannot take place immediately, bridging therapy is often used for patients who are on the transplant waiting list. Guidelines from the American Association for the Study of Liver Diseases (AASLD) recommend bridging therapy when the expected transplant wait time is 6 months or longer. The aim of such therapy is to control tumor growth and prevent the cancer from progressing while waiting for a donor liver. Options for bridging therapy usually include:

• Microwave ablation (MWA) or radiofrequency ablation (RFA) — for patients with tumors 3 cm or less
• Transarterial chemoembolization (TACE) or transarterial radioembolization (TARE) - for patients with two or three tumors, larger tumors or those that are difficult to access via ablation

In the United States, some treatment centers practice bridging therapy to downstage patients whose tumors initially do not meet the Milan criteria. Downstaging involves treating the cancer to reduce the size and number of tumors, making the patient eligible for transplantation.

There are currently no official guidelines or international consensus on the best method for downstaging.

The Organ Procurement and Transplantation Network (OPTN) and the United Network for Organ Sharing (UNOS) mandate a six-month observation period to ensure proper selection of downstaged candidates for transplantation.

The OPTN/UNOS 6-month observation period applies to patients undergoing downstaging to reduce the size and number of liver tumors. Once the observation period is complete, and if the patient’s tumors remain within Milan criteria, they may be granted exception points. These points elevate the patient’s priority on the transplant list.

By meeting the Milan criteria and addressing factors like MELD score, patients improve their chances of ranking higher on the transplant waiting list.

For example, Luana had a successful liver transplant after successfully downstaging her liver tumor. Like many people with liver cancer, her cancer journey began with hepatitis C. She discovered a liver tumor that turned out to be hepatocellular carcinoma (the most common type of liver cancer) during a routine exam in 2016.

At that point, the tumor was too large for her to be considered for a transplant. Luana underwent bridging therapy with Y90 radioembolization to shrink the tumor. Fortunately, after the six-month observation period, her MELD score improved, placing her on the liver transplant list.

Understanding your eligibility for a liver transplant is a crucial step as you explore your treatment options. While not every patient may qualify, the criteria ensure that those who receive a transplant have the best possible chance for long-term success and improved quality of life.