Effect of postoperative chemotherapy on the serum alpha-fetoprotein level in hepatoblastoma

Identification of an HLA-A*24:02-restricted α-fetoprotein signal peptide-derived antigen and its specific T-cell receptor for T-cell immunotherapy

Hepatocellular carcinoma (HCC) is the most common type of liver cancer with limited treatments. Asia has the highest HCC incidence rates; China accounts for over 50% of all HCC cases worldwide. T-cell receptor (TCR) -engineered T-cell immunotherapies specific for human leukocyte antigen (HLA) -A*02:01-restricted α-fetoprotein (AFP) peptide have shown encouraging results in clinics. HLA-A*24:02 is more common than HLA-A*02:01 in Asian countries, including China. Here we identified a novel HLA-A*24:02-restricted peptide KWVESIFLIF (AFP_2-11 ) located in AFP signal peptide domain by mass spectrometric analysis of HLA-bound peptides from HepG2 cells. A TCR (KWV3.1) specific for AFP_2-11 -HLA-A*24:02 was isolated from peripheral blood mononuclear cells of a healthy donor. The binding affinity of soluble KWV3.1 to its antigen was determined to be ~55 μm, within the affinity range of native TCRs for self-antigens. KWV3.1-transfected T cells could specifically activate and kill AFP_2-11 pulsed T2-A24 cells and AFP⁺  HLA-A*24:02⁺ tumor cell lines, demonstrating that AFP_2-11 can be naturally presented on the surface of AFP⁺ tumor cell lines. The newly identified antigenic peptide can provide a novel target for immunotherapeutic strategies for patients with AFP⁺  HLA-A*24:02⁺ HCC.

Pretransplant trends in α-fetoprotein levels as a predictor of recurrence after living donor liver transplantation for unresectable hepatoblastoma: A single-institution experience

LT is a practical therapeutic alternative for unresectable hepatoblastoma; however, deciding when to perform LT is difficult. The aim of this study was to optimize the timing of LT for hepatoblastoma using pretransplant trends in AFP levels. Trends in pretransplant AFP levels and their influence on post-transplant outcomes were retrospectively evaluated. All patients who underwent living donor LT for hepatoblastoma in our institution since 2002 were included. Variables analyzed included history of prior tumor resection, pretransplant AFP responses to chemotherapy, metastatic disease at diagnosis, and post-transplant chemotherapy. Eight patients (seven boys and one girl; median age, 35 months; range, 15 months-12 years) were transplanted. The overall post-transplant recurrence-free survival rate was 62.5% (5/8) with a mean follow-up of 77 months. Patients with post-transplant recurrence showed a 0.573 log increase in AFP levels after the last chemotherapy session before LT. This was significantly higher than the 0.279 log decrease observed in patients without post-transplant recurrence (P = .024). Because the AFP response cannot be accurately predicted before each cycle of chemotherapy, it may be appropriate to perform LT when AFP levels do not decrease after the last cycle and before they are found to be elevated again.

Histological and immunohistochemical study of hepatoblastoma: correlation with tumour behaviour and survival

Background

Hepatoblastoma (HB) has different histological subtypes, with varying prognosis. Though the survival has drastically improved, subsets of patients are not responsive to therapy. Therefore, it becomes important to determine the factors which affect the behaviour of the tumour. This study was aimed to look at the histopathological subtypes and compare with immunohistochemical (IHC) expression of CK19, beta-catenin and EpCAM and survival.

Methods

This study included 55 cases of HB. IHC expression of CK19, beta-catenin and EpCAM were correlated with histological subtypes, tumour behaviour, response to chemotherapy and survival.

Results

Most common epithelial subtype was fetal (43.2%) and mixed epithelial (54.8%) in pre- and post-chemotherapy groups respectively. Microvascular invasion (MVI) was present in 14/33 resected tumours. CK19 expression was seen in 54.2% and 72.2% of embryonal subtype, nuclear beta-catenin expression in 48.7% and 57.1% and EpCAM in 100% and 82.1% of tumours in pre- and post-chemotherapy groups, respectively. Fetal subtype had a lesser chance of MVI, recurrence, metastasis and death. Beta-catenin expression was associated with lower event free survival (EFS) and EpCAM with ≥50% viable tumour following chemotherapy (P=0.04). Age at diagnosis ≤2 years, male sex, alpha-fetoprotein <10,000 IU/mL following chemotherapy, solitary tumour (P=0.001), size ≤5 cm, pretreatment extent of disease (PRETEXT) I&II, mitosis ≤2/10 high power fields (hpf), viable tumour <50% (P=0.04) and absent nuclear expression of beta-catenin, predicted a higher EFS rate.

Conclusions

Beta-catenin expression is associated with lower EFS and EpCAM expression with tumour viability. Multifocality and viable tumour ≥50% were significant factors predicting lower EFS. These factors should be included in the prognostication of HBs.

Hepatoblastoma: current understanding, recent advances, and controversies

Introduction: Hepatoblastoma (HB) is the most common primary malignant liver neoplasm in children. Its increasing survival rate is related to the progress in modern imaging, surgical techniques, and new chemotherapy regimens.

Clinical approach: One of the past achievements was the development of the pretreatment extension of disease (PRETEXT) system. Gradually, the HB therapeutic approach has become more individualized with better stratification of patients.

Controversies: These include the need for preoperative chemotherapy and its optimal duration; intensity of preoperative chemotherapy required for locally advanced cases (PRETEXT 4); optimal surgical treatment for locally advanced tumors: aggressive hepatic resections versus liver transplantation; the role of postoperative chemotherapy in the post-transplant setting; the timing and role of metastasectomy in patients with disseminated disease who undergo partial liver resection; and the prognostic significance of several HB pathology variants.

Hepatoblastoma biology: Beta-catenin mutations and the beta-catenin/Wnt pathway play an important role in HB development. There have been at least two molecular signatures in HB published. Unluckily, all of these findings are based on relatively small clinical series and require confirmation.

Conclusion: The treatment of HB started from one and the same therapy for all patients and aimed at increased treatment individualization, but the future seems to lie in biology-driven patient-tailored therapies.

The Collagen Gel Droplet-embedded Culture Drug Sensitivity Test in Relapsed Hepatoblastoma

There are few treatment options for patients with unresectable or refractory hepatoblastoma which has failed to respond to the standard treatment. The rarity of the disease and lack of experimental materials have hampered the development of new treatments. In this study, the collagen gel droplet-embedded culture drug sensitivity test was used to evaluate the effectiveness of the multikinase inhibitors sorafenib and sunitinib, and other drugs, in relapsed hepatoblastoma tumor tissues. Tumor samples from 6 patients with relapsed hepatoblastoma were tested for drug sensitivity by the collagen gel droplet-embedded culture drug sensitivity test; evaluable results were obtained from 5 of them. All samples were judged to be sensitive to sorafenib with a 50% growth inhibitory concentration (IC50) of 0.5 to 3.1 μg/mL. Sunitinib did not achieve IC50 in 2 of 3 samples within the tested concentration range based on clinically observed serum concentrations. In the drug combination assay using a hepatoblastoma cell line, sorafenib showed synergistic effects with SN-38, an active metabolite of irinotecan. Our results provide the basic science background warranting future clinical trials of a combination of sorafenib and irinotecan for relapsed or refractory hepatoblastoma.

Paraneoplastic recurrent hypoglycaemic seizures: an initial presentation of hepatoblastoma in an adolescent male-a rare entity

Hepatoblastoma (HB) is a rare malignant tumour of the liver and usually occurs in the first three years of life. Hepatoblastoma in adolescents and young adults is extremely rare; nevertheless the prognosis is much worse than in childhood, because these kinds of tumours are usually diagnosed late. Characteristic imaging and histopathological and AFP levels help in the diagnosis of hepatoblastoma. Paraneoplastic features of hepatoblastoma are not uncommon at presentation and include erythrocytosis, thrombocytosis, hypocalcaemia, isosexual precocious puberty, and rarely hypoglycaemia. Even though hypoglycaemia is commonly seen in hepatocellular carcinoma, its association with hepatoblastoma is very rare. We present a case of 15-year-old male patient presenting with complaints of recurrent hypoglycaemic seizures ultimately leading to diagnosis of hepatoblastoma. Managed successfully with neoadjuvant chemotherapy, surgery and adjuvant chemotherapy with adriamycin and cisplatin based regimens. An extensive review of literature in the PubMed and MEDLINE did not reveal much data on paraneoplastic recurrent hypoglycaemic seizures as an initial presentation of hepatoblastomas in adolescents and young adults.

Embryonal/Fetal subtype hepatoblastoma: a case report

Hepatoblastoma is the most common primary liver tumor of childhood and after neuroblastoma and nephroblastoma the third most common abdominal neoplasm in this age group. Hepatoblastoma is an embryonal tumor classified by histology as epithelial (including pure fetal subtype, mixed embryonal/fetal subtype, macrotrabecular subtype and small cell undifferentiated subtype), mixed epithelial and mesenchymal type (with teratoid and non-teratoid features) and hepatoblastoma not otherwise specified. We present a case of a five-months old girl with embryonal/fetal subtype hepatoblastoma. The clinical presentation was asymptomatic abdominal mass. Ultrasound and MRI scan demonstrated a solid hepatic tumor. She presented thrombocytosis and serum alpha-fetoprotein was increased. A left lobe hepatectomy was performed and the pathological examination revealed complete excision of a mixed embryonalfetal subtype hepatoblastoma.

Lentivirally engineered dendritic cells activate AFP-specific T cells which inhibit hepatocellular carcinoma growth in vitro and in vivo

α-fetoprotein (AFP), a tumor-associated antigen for hepatocellular carcinoma (HCC), is an established biomarker for HCC. In this study, we created a lentivirus expressing the AFP antigen and investigated the anti-tumor activity of AFP-specific CD8+ T cells, with and without CD4+ T cells, which were activated by either AFP peptide-pulsed or Lenti-AFP-engineered Dendritic cells (DCs) in vitro and in vivo. AFP-specific T cells could efficiently kill HepG2 HCC cells, and produced IL-2, IFN-γ, TNF-α, perforin and granzyme B, with minimal production of IL-10 (a negative regulator of T cell activation). Both strategies activated AFP-specific T cells, but the lentiviral strategy was superior by several measures. Data also support an impact of CD4+ T cells in supporting anti-tumor activity. In vivo studies in a xenograft HCC tumor model also showed that AFP-specific T cells could markedly suppress HCC tumor formation and morbidity in tumor-bearing nude mice, as well as regulate serum levels of related cytokines and anti-tumor molecules. In parallel with human in vitro T cell cultures, the in vivo model demonstrated superior anti-tumor effects and Th1-skewing with Lenti-AFP-DCs. This study supports the superiority of a full-length antigen lentivirus-based DCs vaccine strategy over peptides, and provides new insight into the design of DCs-based vaccines.

High survival rates after liver transplantation for hepatoblastoma and hepatocellular carcinoma

Unresectable malignant liver tumors may be treated by LTx. We evaluated the results of LTx for HB and HCC. All patients transplanted for HB or HCC between 1990 and 2007 were included. Effects of histologic tumor type, primary tumor resection, disease staging, and serum AFP levels at diagnosis and at transplantation on disease recurrence and survival were evaluated. Twelve patients with median age of five (range, 2-16) were transplanted and followed for a median of 11 (2-18) yr. Six patients had HB and six had HCC. At diagnosis, eight patients were staged as PRETEXT III and four patients as PRETEXT IV. Two patients had pulmonary metastases. All patients received neoadjuvant chemotherapy. Median time from diagnosis to LTx was seven (2-133) months. At LTx, none of the patients had radiological evidence of extrahepatic disease, and the median AFP level was 85 (6-15 180) microg/L. No routine chemotherapy after LTx was used.The overall one-, five-, and 10-yr cumulative survival rates were 100%, 80%, and 67%, respectively. Survival was comparable between the two tumor types (4/6 for both). Two deaths occurred secondary to tumor recurrence, one of each tumor type. Both of these patients had an AFP response of <99%. Six of eight patients with primary LTx survived, when compared to two of four transplanted after primary resection. PRETEXT tumor staging had no effect on survival. LTx even without post-transplantation chemotherapy is an effective treatment option for unresectable HB and HCC with comparable survival. Incomplete AFP response to chemotherapy and primary tumor resection were associated with decreased survival.

Establishment and characterization of a cancer cell line derived from an aggressive childhood liver tumor

BACKGROUND

Hepatoblastoma is a rare malignancy of childhood. The scarcity of adequate cell models has limited our understanding of this tumor. Here we describe and characterize a new human liver tumor cell line, Hep293TT, derived from an aggressive childhood hepatoblastoma.

PROCEDURES

Hep293TT cells were established using primary tumor tissues from a 5-year-old Caucasian female child. This cell line has been maintained for more than 34 months and over 20 subcultures, and was characterized by histopathology, ELISA, genotype, cytogenetics, CGH array, immunohistochemistry, and molecular sequence analyses.

RESULTS

Cells were confirmed to originate from parental tumor cells, secrete alpha-fetoprotein, and express hepatic markers and beta-catenin. Hep293TT cells were able to form colonies in soft agar. Tumorigenicity was demonstrated by induction of solid tumors after subrenal capsule injection in immunodeficient mice. Hep293TT cells demonstrated a highly aneuploid karyotype, and a whole genome CGH analysis revealed chromosomal imbalances in every chromosome. Allelotype analysis demonstrated loss of alleles at distal 11p15.5 as is typical of embryonal tumors. Both Hep293TT cells and the primary tumor contain a deletion of 351 nucleotides in beta-catenin, as has been seen in other hepatoblastoma tumors. The cell line expressed beta-catenin protein in both full-length and partially deleted forms, and expressed NOTCH2 protein characteristic of hepatoblasts. No mutation was detected in the APC, MYH, MLH1, or MSH2 genes.

CONCLUSION

This cell line, Hep293TT, is a valuable resource for the study of childhood liver cancer and may potentially provide a tool in the development of new agents.

Loss of carcinoembryonic antigen-related cell adhesion molecule 1 expression predicts metachronous pulmonary metastasis and poor survival in patients with hepatoblastoma

PURPOSE

Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is a member of the carcinoembryonic antigen family of immunoglobulin-like adhesion molecules. The aim of this study was to test the hypothesis that loss of CEACAM1 expression in hepatoblastoma cells may promote hematogeneous metastasis and function as an adverse prognostic factor.

METHODS

Immunohistochemical expression of CEACAM1 in surgically resected specimens from 19 patients with hepatoblastoma was examined retrospectively. The CEACAM1 expression in the epithelial area of the tumor was classified into 2 categories as follows: diffuse expression, characterized by positive staining throughout the tumor specimen, or loss of expression, in which there were distinct areas of negative staining within the tumor specimen.

RESULTS

Of the 19 patients, 12 were classified as having tumors with diffuse expression, and 7 had loss-of-expression tumors. Survival after treatment was significantly worse in patients with tumors with loss of CEACAM1 expression (cumulative 5-year survival rate, 29%) than in patients with diffuse CEACAM1 expression (cumulative 5-year survival rate, 92%; P = .0062). Loss of CEACAM1 expression was a significant risk factor for metachronous pulmonary metastases (P = .0105).

CONCLUSIONS

Loss of CEACAM1 expression may reflect a high metastatic potential and thus indicate a poor prognosis for patients with hepatoblastoma.

Survival after liver transplantation for hepatoblastoma: a 2-center experience

PURPOSE

Complete resection with adjuvant chemotherapy is the accepted treatment for hepatoblastoma. The aim of this study is to evaluate our results of liver transplantation (LT) for tumors still unresectable after adequate chemotherapy.

METHODS

All patients transplanted for hepatoblastoma from 2 institutions between 1990 and 2004 were included. Variables reviewed to determine impact on survival included the following: previous tumor resection, metastatic disease at diagnosis, microscopic vascular invasion, alpha-fetoprotein (AFP) levels at diagnosis and at transplant, tumor histology, and administration of posttransplantation chemotherapy. Effectiveness of pretransplantation chemotherapy was defined as a drop of more than 99% in peak AFP levels.

RESULTS

Fourteen patients were transplanted: 9 boys and 5 girls (age range, 18 months-13 years; mean age, 57 +/- 48 months). Patients were transplanted a mean of 4 +/- 1 months after diagnosis. Overall survival was 71% (10/14) with a mean follow-up of 46 months. All deaths were secondary to recurrent tumor. Of 10 patients who underwent a primary LT, 9 survived compared to only 1 of 4 transplanted for unresectable tumor recurrence after primary resection (90% vs 25%; P = .02). Decline in peak AFP of more than 99% was also associated with better survival (100% vs 56%; P = .08). Similarly, patients who received posttransplantation chemotherapy had 100% survival compared with 56% without chemotherapy (P = .08). Other variables had little effect on survival.

CONCLUSIONS

Liver transplantation is a successful treatment option for children with unresectable hepatoblastoma with a 90% survival rate for primary transplantation. Rescue LT for recurrent hepatoblastoma after previous resection has a poor survival outcome and should be considered a relative contraindication. Posttransplantation chemotherapy improves survival. A prospective multicenter collaboration to validate these findings with a larger patient population is necessary. Until that time, patients who receive rescue transplants should receive posttransplantation chemotherapy.

AFP-specific CD4+ helper T-cell responses in healthy donors and HCC patients

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and is often diagnosed at an advanced stage. We have investigated alpha-fetoprotein (AFP) as a tumor-associated antigen for HCC. We identified major histocompatibility complex class I-restricted peptide epitopes derived from AFP and studied CD8 T-cell responses in vivo and in vitro in ongoing immunotherapy studies. Helper T cells are of critical importance in shaping the immune response; therefore, we investigated the frequency and function of AFP-specific CD4 T cells in the general population and among HCC patients. CD4 T-cell responses were assessed by direct ex vivo multicytokine enzyme-linked immunospot assay and by measurement of cytokine levels using a multicytokine assay. Our analysis indicates that healthy donors have very low frequencies of AFP-specific CD4 T-cell responses, which are of TH1 type, detectable ex vivo. In contrast, these T cells were either reduced or eliminated in HCC patients at advanced stages of disease. To better activate these cells, we compared the stimulatory capacity of both AFP protein-fed and AdVhAFP-engineered dendritic cells (DC). Healthy donors have CD4 T-cell responses, which were activated in response to AFP protein-fed DC whereas HCC patients do not demonstrate significant responses to AFP protein. AdVhAFP-transduced DC were capable of activating higher frequency TH1 CD4 responses to AFP in both healthy donors and AFP-positive HCC patients. Importantly, CD4 T-cell cytokine expression profiles were skewed towards interleukin-2 and interferon-gamma production when activated by adenovirally engineered DC, which has therapeutic implications for vaccination efforts.