In this study, researchers reviewed the detailed medical records of 262 patients under age 20 diagnosed with liver cancers, assembled from 19 different hospitals and covering the years 1990 to 2017. This represents the richest available source of data on these pediatric liver cancers. They found that 119 (45%) of the tumors had been classified as FLC, 110 (42%) as conventional HCCs, and the remainder mainly as “tumors with features of both hepatoblastomas and HCC” (HB-HCC) (12%).
They discovered that each cancer subtype has different clinical characteristics and identified factors associated with higher mortality, including advanced tumor stage, involvement of certain liver structures, and the presence of multiple tumors.
Key findings from the effort included:
- 177 (67.6%) patients had their tumors resected during their treatment; 112 (42.4%) underwent resection at diagnosis. Of these, 90 underwent a partial hepatectomy, and 22 had a liver transplant (OLT). 81 (30.9%) of the children never underwent resection.
- An “R0 resection” (meaning that there is no residual tumor after microscopic examination of the surgical margin) was more commonly achieved in FLC (64.7%) and HB-HCC (69.7%) than in cHCC.
- 146 (55.7%) patients were able to achieve disease-free status; these rates were similar between tumor types.
- Patients with cHCC and HB-HCC trended to relapse more frequently in the liver. Those who had FLC relapsed more frequently outside the liver and lung, with 16 of 35 patients relapsing in lymph nodes, suggesting the need for thorough lymph node examination during surgery.
- 128 (49.8%) of the children died. Long-term mortality rates were similar between those having FLC (51.7%) and cHCC (50%).
- There were significant differences in the median time from diagnosis to death between subtypes (21.6 months in cHCC vs 31.2 months in FLC vs 50.1 months in HB-HCC).
- Attaining disease-free status at any point was correlated with survival, which supports an aggressive surgical approach for all children with these diseases.
The study acknowledged challenges in classifying these rare tumors accurately, and limitations included the lack of central histologic review and molecular characterization for all the tumors. Despite these challenges, this research advanced the understanding of these cancers. Ongoing efforts and molecular analyses are expected to provide further insights and inform future treatment strategies.
Note: In 2023, FCF funded a follow-on effort by the PSORC team to carry out a centralized pathology review and molecular analyses of the 262 tumors in the PSORC collection to further refine the clinical correlations.