Multifocal hepatoblastoma: What is the risk of recurrent disease in the remnant liver?

Intratumoral CXCR4hi neutrophils display ferroptotic and immunosuppressive signatures in hepatoblastoma

Pediatric hepatoblastoma (HB) is the most common primary liver malignancy in infants and children. With great diversity and plasticity, tumor-infiltrating neutrophils were one of the most determining factors for poor prognosis in many malignant tumors. In this study, through bulk RNA sequencing for sorted blood and tumor-infiltrated neutrophils and comparison of neutrophils in tumor and para-tumor tissue by single-cell sequencing, we found that intratumoral neutrophils were composed of heterogenous functional populations at different development stages. Our study showed that terminally differentiated neutrophils with active ferroptosis prevailed in tumor tissue, whereas, in para-tumor, pre-fate naïve neutrophils were dominant and ferroptotic neutrophils dispersed in a broad spectrum of cell maturation. Gene profiling and in vitro T-cell coculture experiment confirmed that one of main functional intratumoral neutrophils was mainly immunosuppressive, which relied on the activation of ferroptosis. Combining the bulk RNA-seq, scRNA-seq data, and immunochemistry staining of tumor samples, CXCL12/CXCR4 chemotaxis pathway was suggested to mediate the migration of neutrophils in tumors as CXCR4 highly expressed by intratumoral neutrophils and its ligand CXCL12 expressed much higher level in tumor than that in para-tumor. Moreover, our study pinpointed that infiltrated CXCR4hi neutrophils, regardless of their differential distribution of cell maturation status in HB tumor and para-tumor regions, were the genuine perpetrators for immune suppression. Our data characterized the ferroptosis-dependent immunosuppression energized by intratumoral CXCR4 expression neutrophils and suggest a potential cell target for cancer immunotherapies.

Hepatoblastoma Relapse-Findings from the German HB99 Trial and the German Liver Tumor Registry

Survival rates for HB patients have improved; however, outcomes for patients who relapse remain poor. A retrospective review of information gathered for the HB99 study and the German Liver Tumor Registry identified 25 relapse patients (6.9%, 25/362). The median time from initial diagnosis to first relapse was 13 months (range: 5-66 months). Two patients relapsed >36 months after initial diagnosis. A total of 68% (17/25) of relapses were metastatic, 24% local, and 8% combined. 67% of local relapses were alive at the last follow-up, in contrast to 53% of metastatic and 0% of combined relapses. At the last follow-up, 73% (8/11) of patients with lung relapses were still alive (0/4 with peritoneal, 1/2 with CNS involvement). A total of 20% of the patients had AFP-negative relapses, 64% of the relapse patients achieved a second complete remission, 69% were still in complete second remission at the last follow-up (median FU of 66 months), and 83% (5/6) of irinotecan-naïve patients who received relapse treatment including irinotecan were in second complete remission at the last follow-up. The 3-year overall survival/event-free survival from relapse was 63%/48% respectively. There is a good chance that HB patients will achieve a second remission despite a first relapse. However, patients who suffer further relapses tend to have a poorer prognosis.

Surgical Management and Outcomes of Patients with Multifocal Hepatoblastoma

OBJECTIVE

To compare the outcomes of patients with multifocal hepatoblastoma (HB) treated at our institution with either orthotopic liver transplant (OLTx) or hepatic resection to determine outcomes and risk factors for recurrence.

BACKGROUND

Multifocality in HB has been shown to be a significant prognostic factor for recurrence and worse outcome. The surgical management of this type of disease is complex and primarily involves OLTx to avoid leaving behind microscopic foci of disease in the remnant liver.

METHODS

We performed a retrospective chart review on all patients <18 years of age with multifocal HB treated at our institution between 2000 and 2021. Patient demographics, operative procedure, post-operative course, pathological data, laboratory values, short- and long-term outcomes were analyzed.

RESULTS

A total of 41 patients were identified as having complete radiologic and pathologic inclusion criteria. Twenty-three (56.1%) underwent OLTx and 18 (43.9%) underwent partial hepatectomy. Median length of follow-up across all patients was 3.1 years (IQR 1.1-6.6 years). Cohorts were similar in rates of PRETEXT designation status identified on standardized imaging re-review (p = .22). Three-year overall survival (OS) estimate was 76.8% (95% CI: 60.0%-87.3%). There was no difference in rates of recurrence or overall survival in patients who underwent either resection or OLTx (p = .54 and p = .92 respectively). Older patients (>72 months), patients with a positive porta hepatis margin, and patients with associated tumor thrombus experienced worse recurrence rates and survival. Histopathology demonstrating pleomorphic features independently associated with worse rates of recurrence.

CONCLUSIONS

Through proper patient selection, multifocal HB was adequately treated with either partial hepatectomy or OLTx with comparable outcome results. HB with pleomorphic features, increased patient age at diagnosis, involved porta hepatis margin on pathology, and the presence of associated tumor thrombus may be associated with worse outcomes regardless of the local control surgery offered.

LEVEL OF EVIDENCE

III.

Genome-wide mapping of cancer dependency genes and genetic modifiers of chemotherapy in high-risk hepatoblastoma

A lack of relevant genetic models and cell lines hampers our understanding of hepatoblastoma pathogenesis and the development of new therapies for this neoplasm. Here, we report an improved MYC-driven hepatoblastoma-like murine model that recapitulates the pathological features of embryonal type of hepatoblastoma, with transcriptomics resembling the high-risk gene signatures of the human disease. Single-cell RNA-sequencing and spatial transcriptomics identify distinct subpopulations of hepatoblastoma cells. After deriving cell lines from the mouse model, we map cancer dependency genes using CRISPR-Cas9 screening and identify druggable targets shared with human hepatoblastoma (e.g., CDK7, CDK9, PRMT1, PRMT5). Our screen also reveals oncogenes and tumor suppressor genes in hepatoblastoma that engage multiple, druggable cancer signaling pathways. Chemotherapy is critical for human hepatoblastoma treatment. A genetic mapping of doxorubicin response by CRISPR-Cas9 screening identifies modifiers whose loss-of-function synergizes with (e.g., PRKDC) or antagonizes (e.g., apoptosis genes) the effect of chemotherapy. The combination of PRKDC inhibition and doxorubicin-based chemotherapy greatly enhances therapeutic efficacy. These studies provide a set of resources including disease models suitable for identifying and validating potential therapeutic targets in human high-risk hepatoblastoma.

Surgical Resection of Hepatoblastoma: Factors Affecting Local Recurrence

INTRODUCTION

 This study aimed to investigate potential factors contributing to local recurrence after surgical resection of hepatoblastoma (HB).

MATERIALS AND METHODS

 This retrospective study involving all patients with HB who underwent nontransplant surgery at our tertiary center between July 2007 and July 2018. Data were analyzed regarding microscopic surgical resection margin, tumor multifocality and extracapsular tumor extension in correlation with local recurrence. These relations were assessed by logistic regression.

RESULTS

 The study included 133 patients with a median age of 1.3 years (range: 0.5-12.8 years). They were classified into 99 cases (74.44%) standard risk and 34 cases (25.56%) high risk. Delayed surgical resection was adopted in all patients. Follow-up to July 2019 revealed that 23 patients (23/133, 17.3%) developed local recurrence, whereas the remaining 110 were locally disease free. Microscopic positive margin (R1) was detected in 29 patients, 8 of them had local recurrence (p = 0.097). Regarding tumor multifocality, there were 12 patients who had multifocal lesions, 3 of them developed local recurrence (p = 0.459). Forty-four patients had extracapsular tumor extension in their pathological reports, 12 of them had local recurrence (p = 0.032).

CONCLUSION

 Extracapsular tumor extension was a significant prognostic factor of local recurrence after surgical resection of HB. R1 margin does not necessarily require a second resection, and it could achieve accepted results when combined with adjuvant platinum-based chemotherapy. However, patients who are not eligible for surgical resection must be transferred for primary transplantation to obtain favorable outcome.

Outcomes of Central Hepatectomy for Pediatric Liver Tumors

BACKGROUND

Central hepatectomy (CH) is an uncommon surgical technique that is an option for resection of centrally located tumors, with the advantage of sparing normal hepatic parenchyma. Few studies have described outcomes in children undergoing CH.

MATERIALS AND METHODS

An IRB-approved, retrospective chart review of patients who underwent CH at Children's Hospital Los Angeles between 2005 and 2016 was performed. Data included patient demographics, peri-operative factors, and post-operative outcomes. The IRB approved waiver of consent.

RESULTS

Eight patients (4F:4M) with median age of 1.9 Y underwent CH: 7 patients for HB and 1 patient for focal nodular hyperplasia. Two of the seven HB patients had metastatic disease at diagnosis. Six of the seven HB patients received a median of 4 rounds (3-7 rounds) of pre-operative chemotherapy. The median operative time was 197.5 Min (143-394 Min) with median blood loss of 175 mL (100-1200 mL). Complications included a bile fluid collection requiring aspiration. Seven patients had negative margins on pathology. One patient with a positive margin successfully completed therapy, without recurrent disease. All patients survived to follow-up, with a median follow-up duration of 1.1 Y (0.1-12.1 Y). Two patients developed recurrent disease requiring formal hepatic lobectomy and orthotopic liver transplantation. These patients had negative pathologic margins, with tumor within 1 mm of resection margins.

CONCLUSION

CH is an effective alternative to extended hepatectomy for patients with centrally located liver tumors and is associated with good clinical and pathologic outcomes.

Hepatoblastoma with multiple tumors in a school-aged child

Clinicians need to consider hepatoblastoma in the differential even in school-aged children or adolescents presenting with multiple liver tumors.

Surgical management of locally-advanced and metastatic hepatoblastoma

Advanced stage hepatoblastoma, including both locally advanced primary tumors as well as metastatic disease, poses unique clinical challenges. Despite substantial advances in chemotherapeutics, surgical extirpation remains the mainstay of cure for this tumor. Locally advanced tumors that involve multiple hepatic lobes and/or invade significant vascular structures can be managed either by complex hepatic resections or liver transplantation. We review the indications, roles, and outcomes of these surgical approaches as well as those for the resection of pulmonary metastases.

Impact of microscopically margin-positive resection on survival in children with hepatoblastoma after hepatectomy: a retrospective cohort study

BACKGROUND

Impact of R1 (microscopically margin-positive) resection on survival of patients with hepatoblastoma (HB) remains debatable. This study aimed to compare the long-term outcomes of R0 (microscopically margin-negative) and R1 resection for HB in children after hepatectomy.

METHODS

We retrospectively reviewed files of children with HB who underwent resection at our institution between September 1, 2005, and November 30, 2017. Survival analyses and prognostic factors were evaluated using Kaplan-Meier curves and Cox regression models.

RESULTS

Of 259 patients, 218 (84.2%) underwent R0 and 41 (15.8%) R1 resection. After adjusting for confounding factors, R1 resection demonstrated non-significantly lower overall survival (OS: hazard ratio [HR] = 0.75; 95% CI 0.34-1.64) and shorter event-free survival (EFS: HR = 0.97; 95% CI 0.53-1.78) rates than R0 resection. However, stratified analysis showed significantly increased risk of poor OS and EFS in patients with metastasis and mixed epithelial/mesenchymal pathologic subtype in R1 compared with R0 resection (P values for interactions < 0.05). There was no significant difference between R0 resection with metastasis and R1 resection with metastasis in the incidence of local recurrence (P = 0.494); however, a significant difference in the incidence of local recurrence was seen between R0 and R1 resection for subgroups with mixed pathologic subtypes (P = 0.035).

CONCLUSIONS

With effective chemotherapy, microscopic margin status may not be associated with survival outcome in children with HB undergoing hepatectomy. However, stratified analysis showed that R1 resection might be associated with decreased survival in children with mixed epithelial/mesenchymal HB, compared with R0 resection, and not affect survival outcomes in those with an epithelial subtype and without metastasis.