Autologous peripheral blood stem-cell transplantation with a double-conditioning regimen for recurrent hepatoblastoma after liver transplantation--a valid therapeutic option or just too much?

Retreatment with Cisplatin May Provide a Survival Advantage for Children with Relapsed/Refractory Hepatoblastoma: An Institutional Experience

BACKGROUND

Hepatoblastoma (HB) is the most common liver malignancy in children. There is no standard of care for management of relapsed/refractory HB (rrHB) and reports in the literature are limited.

OBJECTIVE

To describe presenting features, biology, treatment strategies, and outcomes for pediatric patients with relapsed/refractory hepatoblastoma.

METHODS

An IRB-approved retrospective institutional review of patients with rrHB who presented for consultation and/or care from 2000-2019. Clinical, radiographic, and histologic data were collected from all patients.

RESULTS

Thirty subjects were identified with a median age of 19.5 months (range 3-169 months) at initial diagnosis and 32.5 months (range 12-194 months) at time of first relapse. 63% of subjects were male, 70% Caucasian, and 13% were born premature. Three subjects had a known cancer predisposition syndrome. Eight patients had refractory disease while 22 patients had relapsed disease. Average time from initial diagnosis to relapse or progression was 12.5 months. Average alpha-fetoprotein (AFP) at initial diagnosis was 601,203 ng/mL (range 121-2,287,251 ng/mL). Average AFP at relapse was 12,261 ng/mL (range 2.8-201,000 ng/mL). For patients with tumor sequencing (n = 17), the most common mutations were in CTNNB1 (13) and NRF2 (4). First relapse sites were lungs (n = 12), liver (n = 11) and both (n = 6). More than one relapse/progression occurred in 47% of subjects; 6 had ≥3 relapses. Pathology in patients with multiply relapsed disease was less differentiated including descriptions of small cell undifferentiated (n = 3), pleomorphic (n = 1), transitional liver cell tumor (n = 2) and HB with carcinoma features (n = 1). All subjects underwent surgical resection of site of relapsed disease with 7 subjects requiring liver transplantation. Overall survival was 50%. Survival was associated with use of cisplatin at relapse (78.6% with vs. 25% without, p = 0.012). The most common late effect was ototoxicity with at least mild sensorineural hearing loss found in 80% of subjects; 54% required hearing aids.

CONCLUSIONS

Retreatment with cisplatin at the time of relapse may provide an advantage for some patients with hepatoblastoma. Multiply relapsed disease was not uncommon and not associated with a worse prognosis. Careful attention should be paid to cumulative therapy-induced toxicity while concurrently aiming to improve cure.

How Do Synchronous Lung Metastases Influence the Surgical Management of Children with Hepatoblastoma? An Update and Systematic Review of the Literature

Approximately 20% of children with hepatoblastoma (HB) have metastatic disease at diagnosis, most frequently in the lungs. In children with HB, lung metastatic disease is associated with poorer prognosis. Its treatment has been approached with a variety of methods that integrate chemotherapy and surgical resection. The timing and feasibility of complete extirpation of lung metastases, by chemotherapy and/or metastasectomy, is crucial for the surgical treatment of the primary liver tumor, which can vary from major hepatic resections to liver transplantation (LT). In children with unresectable HB, which can be surgically treated only by LT, the persistence of unresectable metastases after neoadjuvant chemotherapy excludes the possibility of recurring to LT with consequent negative impact on patients’ outcomes. Due to limited evidence and experience, there is no consensus amongst oncologists and surgeons across institutions regarding the surgical treatment for HB with synchronous metastatic lung disease. This narrative review aimed to update the current management of pulmonary metastasis in children with HB and to define its role in the decision-making strategy for the surgical approach to primary liver tumours.

Unresectable hepatoblastoma: current perspectives

Although rare, hepatoblastoma is the most common pediatric liver tumor. Complete resection is a critical component for cure; however, most patients will have tumors that are not resected at diagnosis. For these patients, administration of neoadjuvant chemotherapy renders tumors resectable in most patients. For patients whose tumors remain unresectable after chemotherapy, liver transplantation is indicated (in the absence of active unresectable metastatic disease). In patients whose tumors remain unresectable after conventional chemotherapy, interventional techniques may serve as a promising option to reduce tumor size, decrease systemic toxicity, decrease need for liver transplantation, and increase feasibility of tumor resection.

Targeting EpCAM (CD326) for immunotherapy in hepatoblastoma

Hepatoblastoma (HB) is the most common liver cancer in children. Recurrence of HB after chemotherapy and surgery is frequent among high-risk patients and is associated with chemoresistance. Immunotherapy may improve poor treatment outcomes in HB patients. Cytotoxic leukocytes of the innate and adaptive immune system including different populations of cytotoxic T cells play a major role in fighting developing tumors. In this setting, monoclonal antibodies may be employed to specifically direct immune responses toward tumor cells. We addressed this issue by using humanized antibodies that recognize the cell surface molecule EpCAM (CD326, overexpressed in hepatic tumor cells) to enhance immune responses against HB. EpCAM was constantly expressed on HB cells and its expression was independent of previous therapy based on the DNA-damaging agent cisplatin. Co-culture assays performed with two well-described HB cell lines and tumor tissue cultures demonstrated that tumor cell lysis by γδ T cells can be dramatically augmented by applying EpCAM-specific monoclonal antibodies. These data emphasize the value of antitumor immune responses and encourage adapting immunotherapeutic regimens to improve the outcome of high risk HB.

Several important in vitro improvements in the amplification, differentiation and tracing of fetal liver stem/progenitor cells

Objective

We previously isolated fetal liver stem/progenitor cells (FLSPCs), but there is an urgent need to properly amplify FLSPCs, effectively induce FLSPCs differentiation, and steadily trace FLSPCs for in vivo therapeutic investigation.

Methods

FLSPCs were maintained in vitro as adherent culture or soft agar culture for large-scale amplification. To direct the differentiation of FLSPCs into hepatocytes, FLSPCs were randomly divided into four groups: control, 1% DMSO-treated, 20 ng/ml HGF-treated and 1% DMSO+20 ng/ml HGF-treated. To trace FLSPCs, the GFP gene was introduced into FLSPCs by liposome-mediated transfection.

Results

For amplifying FLSPCs, the soft agar culture were more suitable than the adherent culture, because the soft agar culture obtained more homogeneous cells. These cells were with high nuclear:cytoplasmic ratio, few cell organelles, high expression of CD90.1 and CD49f, and strong alkaline phosphatase staining. For inducing FLSPCs differentiation, treatment with HGF+DMSO was most effective (P<0.05), which was strongly supported by the typical morphological change and the significant decrease of OV-6 positive cells (P<0.01). In addition, the time of indocyanine green elimination, the percentage of glycogen synthetic cells, and the expressions of ALB, G-6-P, CK-8, CK-18 and CYP450-3A1 in HGF+DMSO-treated group were higher than in any other group. For tracing FLSPCs, after the selection of stable FLSPC transfectants, GFP expression continued over successive generations.

Conclusions

FLSPCs can properly self-renew in soft agar culture and effectively differentiate into hepatocyte-like cells by HGF+DMSO induction, and they can be reliably traced by GFP expression.

Current and future management strategies for relapsed or progressive hepatoblastoma

Hepatoblastoma is the most common primary malignant neoplasm of the liver in children. Improvements in chemotherapy and surgical techniques have increased survival rates for those with localized disease. The prognosis for patients with progressive or relapsed disease continues to be dismal. Complete resection by surgery or liver transplantation is necessary for cure. Few conventional chemotherapy agents have demonstrated activity in progressive or relapsed hepatoblastoma. Irinotecan has shown activity in relapsed and progressive hepatoblastoma. The efficacy of high-dose chemotherapy in this setting is unknown. Newer targeted agents that 'selectively' interfere with pathway targets involved in tumor growth and progression such as insulin-like growth factor, phosphatidylinositol 3-kinase (PI3K), Akt, and mammalian target of rapamycin (mTOR) are currently under development. Because of the rarity of hepatoblastoma, only a small minority of these agents will ever be evaluated in children with this disorder. Gene-directed therapy and immunotherapy have shown promising results in the preclinical setting, and should be investigated as future treatment options for advanced hepatoblastoma.