Hepatoblastoma – Diagnostics – Overview of Information and Clinical Research

Hepatoblastoma is the most common primary liver cancer in young children, usually diagnosed before age three. Early and accurate diagnosis is crucial for successful treatment, and various tests help doctors identify this rare condition and determine the best approach to care.

Introduction: When to Seek Diagnostics

Parents and caregivers should consider seeking medical attention when certain warning signs appear in their child. Since hepatoblastoma is a rare condition affecting only about 1 to 2 children per million in the United States, most stomach complaints won’t be related to this cancer. However, if a child displays persistent or unusual symptoms, it’s important not to dismiss them.^[1]

Children who should undergo diagnostic evaluation include those showing unexplained abdominal swelling or a noticeable lump in the upper right side of the belly. When a child loses weight without any clear reason, seems to have lost their appetite, or experiences ongoing nausea and vomiting, these symptoms warrant a doctor’s visit. Another striking sign that should prompt immediate medical attention is jaundice, which is when the skin and the whites of the eyes turn yellow. This happens because the liver isn’t functioning properly.^[1]

Some children are at higher risk for developing hepatoblastoma due to certain conditions they were born with or circumstances surrounding their birth. These include babies born very prematurely or with extremely low birth weight—specifically, weighing less than about 5 pounds at birth. Children with genetic conditions such as Beckwith-Wiedemann syndrome, familial adenomatous polyposis (FAP), Edwards syndrome (also known as trisomy 18), Aicardi syndrome, or hemihyperplasia face increased risk. For these children, doctors may recommend regular monitoring even before symptoms appear.^[2]^[1]

⚠️ Important

Hepatoblastomas grow very slowly, which means children may not show any symptoms until the tumor has become quite large. By the time parents notice something wrong, the disease may already be advanced. That’s why trusting your parental instincts is important—if something feels wrong with your child’s health, don’t hesitate to contact their pediatrician even if the symptoms seem vague or mild at first.

Children already diagnosed with conditions that increase their risk may benefit from special screening programs. These children typically have abdominal ultrasound examinations every three months from birth (or from the time their risk factor is diagnosed) until they reach age four. Blood tests to check a protein called alpha-fetoprotein are also part of this monitoring. These screening tests may help find cancer at an earlier stage, potentially improving the child’s chances of survival.^[2]

Classic Diagnostic Methods

When a child presents with symptoms that might suggest hepatoblastoma, doctors follow a careful process to determine whether liver cancer is present. The journey typically begins with a thorough physical examination where the pediatrician focuses on the abdomen. They will gently feel the belly area to check for any masses or enlarged organs. During this visit, the doctor will ask detailed questions about when symptoms started and how often they occur.^[1]

Blood Tests

Blood tests are among the first diagnostic tools used when hepatoblastoma is suspected. One of the most important is the alpha-fetoprotein (AFP) test. AFP is a protein naturally produced by a child’s liver, and in babies, levels are normally quite high but drop to adult levels by around age two. When hepatoblastoma is present, the tumor often causes AFP levels to rise dramatically. A level greater than 500 nanograms per milliliter is considered a significant indicator of this type of liver cancer. However, it’s important to understand that not all children with hepatoblastoma will have elevated AFP levels—some rare variants of the disease show normal or low AFP, and these cases may have a worse outlook.^[3]^[4]

Beyond the AFP test, doctors order several other blood tests to get a complete picture of the child’s health. A complete blood count (CBC) measures and counts different types of blood cells, which can reveal anemia or other abnormalities. A comprehensive metabolic panel (CMP) examines 14 different substances in the blood and evaluates how well the liver is functioning. Liver function tests provide specific information about whether the liver is working properly or if it has been damaged by the tumor.^[1]

Imaging Studies

Once blood tests suggest a problem, imaging studies help doctors see what’s happening inside the child’s body. Ultrasound is often the first imaging test performed because it’s non-invasive, doesn’t use radiation, and is particularly good at examining the liver. During an ultrasound, sound waves create pictures of the liver’s internal structure. This test can reveal large masses, show satellite lesions (smaller tumors around the main one), and even detect areas of bleeding within the tumor.^[16]^[4]

For more detailed information, doctors use computed tomography (CT) scans or magnetic resonance imaging (MRI). These sophisticated imaging techniques create very clear, detailed pictures of the organs and blood vessels. A CT scan uses X-rays taken from multiple angles, which a computer then combines to create cross-sectional images of the body. An MRI uses powerful magnets and radio waves instead of radiation to generate detailed images. Both tests help doctors see exactly where the tumor is located, how big it is, and whether it has spread to other areas.^[4]^[1]

Vascular ultrasound and Doppler ultrasound are specialized imaging techniques that examine the network of blood vessels entering and leaving the liver. These tests are important because they help surgeons understand whether the tumor has grown into major blood vessels, which affects whether surgery can be safely performed.^[1]

Doctors may also perform imaging of other parts of the body, particularly the lungs and lymph nodes, since hepatoblastoma can sometimes spread to these areas. A chest CT scan or X-ray helps determine whether cancer has metastasized beyond the liver.^[4]

Biopsy Procedures

While blood tests and imaging can strongly suggest hepatoblastoma, the final definitive diagnosis requires examining actual tumor tissue under a microscope. This is done through a biopsy, which is a procedure where a small sample of the tumor is removed for detailed examination. The biopsy can be performed in different ways depending on the situation.^[4]

In many cases, a needle biopsy is performed, where doctors use imaging guidance (such as ultrasound) to direct a needle into the tumor to collect a tissue sample. Sometimes the biopsy is obtained during surgery, particularly if the tumor appears removable at the time of diagnosis. The procedure is always done under general anesthesia, which means the child is completely asleep and feels no pain.^[4]

A specialist called a pathologist examines the biopsy sample under a microscope. This examination reveals critical information about the type of hepatoblastoma, which is classified into different categories based on how the cancer cells look. The histology—meaning the microscopic appearance of the tumor cells—significantly affects treatment decisions and prognosis. For example, well-differentiated fetal histology tends to have better outcomes, while small cell undifferentiated histology is more aggressive. Some tumors show mixed patterns combining different cell types.^[2]

Staging the Disease

After all diagnostic tests are completed, doctors assign a stage to the cancer. Staging describes how much the tumor has grown and whether it has spread beyond the liver. Two main staging systems are used for hepatoblastoma, and understanding both helps doctors plan treatment effectively.^[4]

The PRETEXT staging system (which stands for pretreatment extent of disease) is based on imaging of the liver before any treatment begins. The liver has four main sections called lobes, and the PRETEXT stage depends on how many of these lobes contain tumor. If one lobe is involved, it’s called PRETEXT stage I. If all four lobes contain tumor, it’s PRETEXT stage IV. This system was developed by international liver tumor experts and helps determine which children might benefit from chemotherapy before surgery and which might need more extensive surgery or even liver transplantation.^[4]

The Children’s Oncology Group (COG) staging system takes into account additional information, including imaging of other body parts and the results of surgery if it was performed at diagnosis. COG staging considers how much tumor was removed and whether cancer has spread outside the liver. Stage I means the entire tumor was removed with clear margins (no cancer cells at the edges of removed tissue). Stage II means the tumor was removed but cancer cells were found at the margins. Higher stages indicate tumor that couldn’t be completely removed or cancer that has spread to distant sites.^[4]

⚠️ Important

If your child has been diagnosed with hepatoblastoma, you may be referred to a pediatric oncologist—a doctor who specializes in childhood cancers. Many experts believe that children with large or complex liver tumors achieve the best outcomes when treated at specialized centers with experience in complex liver surgery and pediatric cancer care. Don’t hesitate to ask about seeking care at such centers or obtaining a second opinion from specialists in pediatric liver tumors.

Diagnostics for Clinical Trial Qualification

Clinical trials are research studies that test new treatments or new combinations of existing treatments. Many children with hepatoblastoma are eligible to participate in clinical trials, which may give them access to the most advanced therapies available. However, to ensure that trials are conducted safely and that results are meaningful, children must meet specific diagnostic criteria before they can enroll.^[12]

The diagnostic tests used for clinical trial enrollment are generally the same as those used for standard diagnosis, but they must meet certain quality standards and timing requirements. All major study groups conducting hepatoblastoma trials—including the Children’s Oncology Group in North America, the International Childhood Liver Tumors Strategy Group in Europe (previously known as SIOPEL), and groups in Japan and Germany—require comprehensive testing before a child can join a study.^[16]

Required Blood Work

Clinical trials typically require recent blood test results showing the child’s AFP level, complete blood count, and comprehensive assessment of liver and kidney function. These tests establish a baseline that doctors can use to monitor how the child responds to treatment. They also help ensure that the child’s body is strong enough to tolerate the intensive treatments that may be part of the trial.^[12]

Imaging Requirements

Trials require high-quality imaging studies that clearly show the extent of the tumor. This typically includes CT scans or MRI of the abdomen, as well as chest imaging to check whether cancer has spread to the lungs. Some trials may require specific types of imaging performed according to standardized protocols, which ensures that all children in the study are evaluated consistently. The PRETEXT staging system, developed through international collaboration, has become the standard classification used in most clinical trials worldwide.^[16]

Tissue Analysis

For trial enrollment, pathology confirmation of hepatoblastoma is essential. This means a biopsy must have been performed and the diagnosis confirmed by examining tumor tissue under a microscope. Some trials may also require additional testing on the tumor sample, such as looking for specific genetic mutations or markers. Recent research has identified that many hepatoblastomas have mutations in a cellular pathway called the Wnt signaling pathway, particularly affecting a protein called beta-catenin. Some trials may test for these mutations to better understand the tumor or to select patients most likely to benefit from specific treatments.^[5]

Standardized Assessment

In recent years, major international study groups have worked together to standardize how hepatoblastoma is diagnosed and staged across different countries and institutions. This collaboration, called the Children’s Hepatic Tumors International Collaboration (CHIC), created a shared database that includes data from more than 1,600 children treated in clinical trials around the world. By standardizing diagnostic criteria, classification systems, and data collection, researchers can better understand this rare cancer and develop more effective treatments.^[13]^[16]

For families considering clinical trial participation, the diagnostic workup their child receives as part of standard care will typically meet the requirements for trial enrollment. However, some tests may need to be repeated or additional specialized tests may be required depending on the specific trial. The research team will explain all requirements clearly and help coordinate any additional testing needed.

Prognosis and Survival Rate

Prognosis

The outlook for children with hepatoblastoma depends on several important factors that doctors consider when estimating how well a child might respond to treatment. One of the most significant factors is whether the tumor can be completely removed through surgery. Complete surgical removal of all cancer tissue offers the best chance for cure.^[5]

Alpha-fetoprotein levels at diagnosis and how they change during treatment also provide important prognostic information. Children whose AFP levels drop appropriately during treatment generally have better outcomes. Unfortunately, cases where AFP is low or normal at diagnosis, which can occur with certain tumor variants, tend to have worse prognosis.^[3]

The age of the child at diagnosis plays a role as well. The stage of the disease—meaning how far the cancer has spread and how many sections of the liver are involved—is crucial for predicting outcomes. The presence of metastases, which means cancer that has spread to other parts of the body like the lungs, is the strongest predictor of poor prognosis. Children whose cancer has spread beyond the liver face more challenging treatment and lower survival rates.^[3]^[5]

The microscopic appearance of the tumor cells, called histology, also affects prognosis. Well-differentiated fetal histology typically has the best outcomes, while small cell undifferentiated types and tumors containing rhabdoid features are more aggressive and harder to treat successfully.^[2]

It’s important for families to understand that even after successful treatment, children need long-term follow-up care. Late effects—health issues that appear months or years after treatment—can affect growth and development, organ function, learning and memory, and emotional health. Some children may develop second cancers as a late effect of their initial cancer treatment. Regular monitoring helps doctors identify and manage these issues early.^[1]

Survival Rate

The survival rates for hepatoblastoma have improved dramatically over the past several decades, thanks to advances in both chemotherapy and surgical techniques. In the 1970s, only about 30 percent of children with hepatoblastoma survived. Today, with modern treatment combining chemotherapy and complete surgical removal of the tumor, approximately 70 percent of children can be cured. When caught early and the tumor can be removed completely, survival rates can approach 90 percent.^[5]^[17]

For children whose tumors are completely removed at diagnosis with no cancer remaining at the margins (clean surgical margins), long-term survival rates are excellent. Studies have shown that these children, when treated with appropriate follow-up chemotherapy, can have event-free survival rates of 88 to 92 percent at four to five years after diagnosis.^[12]

Even children whose tumors cannot be removed initially may still achieve good outcomes through a treatment approach that includes chemotherapy first to shrink the tumor, followed by surgery. In some cases where the tumor is too extensive for regular surgery, liver transplantation provides an option that can result in long-term disease-free survival rates of around 80 percent.^[5]

However, survival rates are lower for children whose cancer has spread to distant sites or whose tumors have certain aggressive features. These children require more intensive treatment and face more challenges, though some may still achieve cure with aggressive multimodal therapy that may include chemotherapy, surgery, and potentially liver transplantation.^[5]

#1 Clinical Trials Search in Europe