Liver transplantation in hepatoblastoma

Dr Sarah Berkenfeld, a paediatric gastroenterologist, details when and how a liver transplantation is chosen for treatment of hepatoblastoma.

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Understanding hepatoblastoma

Hepatoblastoma is the most common primary liver cancer in children. In the past 30 years, overall five-year survival post-transplant has improved from 30 to 90%. Hepatoblastoma is staged according to how much of the liver has been invaded by the tumour both before and after chemotherapy and extent of spread of the disease. Cure is highly dependent on removing the tumour in entirety.

For those tumours still unresectable after chemotherapy, total removal of the whole liver and orthotopic liver transplantation (of normal liver or part of one from a deceased or living donor) has proven to be an effective treatment. Recent studies have shown that only 20% of patients diagnosed with hepatoblastoma will ultimately require transplantation.

Pre-treatment extent of disease

At the time of diagnosis, the tumour is staged according to pre-treatment extent of disease (PRETEXT). This staging system takes into account how much of the liver is invaded by tumour, tumour spread beyond the liver and AFP levels at diagnosis (tumour marker).

Some patients may present with an apparent unremovable tumour. However, pre-surgical chemotherapy can lead to downstaging and eventual resection.

Whilst removing a significant part of the liver is possible and has the advantage of avoiding long-term immune suppression associated with liver transplantation, it may leave a small and non-functional liver remnant. Some patients may require salvage liver transplantation as a last resort for tumour recurrence or a non-functional remnant liver. Salvage therapy has been shown to have inferior outcomes when compared to primary liver transplantation.

Liver transplantation recommendations

Current recommendations are to assess the tumour response to chemotherapy and suitability for primary surgery after two cycles of pre-surgical chemotherapy. If primary surgery isn’t feasible, consideration and referral to a liver transplant unit is necessary.

Liver transplantation is a surgical procedure which involves the removal of a non-functioning or diseased liver, and replacement with a healthy, functioning liver. Liver grafts are donated from living donors or deceased donors. Despite hepatoblastoma receiving a priority listing status and access to deceased grafts, these come with disadvantages. The availability of a deceased donor grafts is unpredictable; therefore, predetermined cycles of chemotherapy may be interrupted, and timing of chemotherapy in relation to transplant isn’t possible.

Carefully-timed and planned surgery

Living donor transplantation involves a segment of the living donor’s liver transplanted into the recipient and allows for carefully-timed and planned surgery. The ideal timing is between chemotherapy cycles. Planned surgery allows for the avoidance of cumulative toxic effects of chemotherapy and immunosuppression in close succession. It also prevents the clinical deterioration of patients whilst awaiting a deceased donor organ. In SA, living donor liver transplantation is preferred, given the scarce availability of healthy donor grafts.

The workup leading up to liver transplantation, although extensive, can be implemented in a timeous manner. It involves a medical assessment of the recipient and the live donor. Organ systems including the heart, lungs and kidneys are carefully examined. Screening or co-existing diseases and infections avoids the exacerbation of underlying conditions in the

time leading up to transplant. Psychosocial assessment is essential, given the unprecedented psychosocial stress organ donation and transplant places on a family system.

Complications

Although liver transplantation allows for cure of an otherwise unresectable cancer, it’s not without its complications. Post-transplant complications occur in the immediate and late post-operative period.

Surgical complications include bleeding, clotting of the vessels supplying the liver, and complications involving the bile ducts. Medical complications involve infections, acute and chronic rejection, and long-term immunosuppression and its effects which may include the development of other malignancies.

Screening, preventing and managing these complications requires a commitment to long-term follow-up and medical therapy at a dedicated transplant unit.

Take away message

Liver transplantation for unresectable hepatoblastoma in children provides good results with an overall five-year survival of up to 90%. A multi-disciplinary team and a detailed primary assessment is essential to choosing the correct surgical therapy for optimal results.

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