Deciphering pathological behavior of pediatric medullary thyroid cancer from single-cell perspective.

Background: Pediatric medullary thyroid cancer (MTC) is one of the rare pediatric endocrine neoplasms. Derived from C cells of thyroid glands, MTC is more aggressive and more prompt to metastasis than other types of pediatric thyroid cancer. The mechanism remains unclear. Methods: We performed single-cell transcriptome sequencing on the samples of the primary tumor and metastases lymph nodes from one patient diagnosed with MTC, and it is the first single-cell transcriptome sequencing data of pediatric MTC. In addition, whole exome sequencing was performed and peripheral blood was regarded as a normal reference. All cells that passed quality control were merged and analyzed in R to discover the association between tumor cells and their microenvironment as well as tumor pathogenesis. Results: We first described the landscape of the single-cell atlas of MTC and studied the interaction between the tumor cell and its microenvironment. C cells, identified as tumor cells, and T cells, as the dominant participant in the tumor microenvironment, were particularly discussed in their development and interactions. In addition, the WES signature of tumor cells and their microenvironment were also described. Actively immune interactions were found, indicating B cells, T cells and myeloid cells were all actively participating in immune reaction in MTC. T cells, as the major components of the tumor microenvironment, proliferated in MTC and could be divided into clusters that expressed proliferation, immune effectiveness, and naive markers separately.

Progress of oncolytic virotherapy for neuroblastoma.

As a neuroendocrine tumor derived from the neural crest, neuroblastoma (NB) is the most common extracranial solid tumor in children. The prognosis in patients with low- and intermediate-risk NB is favorable while that in high-risk patients is often detrimental. However, the management of the considerably large proportion of high-risk patients remains challenging in clinical practice. Among various new approaches, oncolytic virus (OV) therapy offers great advantages in tumor treatment, especially for high-risk NB. Genetic modified OVs can target NB specifically without affecting normal tissue and avoid the widespread drug resistance issue in anticancer monotherapy. Meanwhile, its safety profile provides great potential in combination therapy with chemo-, radio-, and immunotherapy. The therapeutic efficacy of OV for NB is impressive from bench to bedside. The effectiveness and safety of OVs have been demonstrated and reported in studies on children with NB. Furthermore, clinical trials on some OVs (Celyvir, Pexa-Vec (JX-594) and Seneca Valley Virus (NTX-010)) have reported great results. This review summarizes the latest evidence in the therapeutic application of OVs in NB, including those generated in cell lines, animal models and clinical trials.

The Cellular and Molecular Landscape of Synchronous Pediatric Sialoblastoma and Hepatoblastoma.

Sialoblastoma (SBL) is an infrequent embryonal malignant tumor originating from the salivary gland, resembling primitive salivary gland anlage, whereas hepatoblastoma (HB) is the most common pediatric liver malignancy. The simultaneous occurrence of both tumors is extremely rare. Here we reported a case of a 6-month-old infant diagnosed with synchronous SBL and HB. The patient received neoadjuvant chemotherapy followed by surgical resection. Fresh tissues of both tumors were collected before and after chemotherapy, which were further profiled by whole exome sequencing (WES) and single-cell RNA sequencing (scRNA-seq). WES analysis revealed potential somatic driver mutation PIK3CA p.Glu454Lys for SBL and canonical mutation CTNNB1 p.Ser45Pro for HB. No shared somatic variants or common copy number alterations were found between SBL and HB primary tumor samples. Though scRNA-seq, single-cell atlases were constructed for both tumors. SBL may recapitulate a pre-acinar stage in the development of salivary gland, including basaloid, duct-like, myoepithelial-like, and cycling phenotypes. In the meantime, HB was composed of tumor cells resembling different stages of the liver, including hepatocyte-like, hepatic progenitor-like, and hepatoblast-like cells. After chemotherapy, both tumors were induced into a more mature phenotype. In terms of transcriptional signatures, SBL and HB showed enhanced expression of epithelial markers KRT8, KRT18, and essential embryo development genes SDC1, MDK, indicating the disruption of normal embryo epithelium development. Finally, heterozygous deleterious germline mutation BLM and FANCI were identified which could predispose the patient to higher cancer risk. It partially explained the reason for the co-occurrence of SBL and HB. Taken together, we provided valuable resources for deciphering cellular heterogeneity and adaptive change of tumor cells after chemotherapy for synchronous SBL and HB, providing insights into the mechanisms leading to synchronous pediatric tumors.

Controversies and evidence of hepatic resection for hepatocellular carcinoma.

Symptoms of early hepatocellular carcinoma (HCC) often go unnoticed, so more than half of patients with primary HCC are diagnosed after their disease has already reached an intermediate or advanced stage, or after portal hypertension has appeared. While hepatic resection is widely recognized as a first-line therapy to treat very early or early HCC, its use in treating intermediate or advanced HCC or HCC involving portal hypertension remains controversial. Here we review PubMed-indexed literature covering the use of hepatic resection for such patients. The available evidence strongly suggests that, as a result of improvements in surgical techniques and perioperative care, hepatic resection can benefit many patients with intermediate or advanced HCC or with HCC associated with portal hypertension.

Reporting and methodological qualities of published surgical meta-analyses.

OBJECTIVES: To assess the overall qualities of published surgical meta-analysis and predictive factors for high qualities. STUDY DESIGN AND SETTING: All meta-analyses pertinent to surgical procedures published in year 2013 were selected from PubMed and EMBASE. The characteristics of the included meta-analyses were collected, and their reporting and methodologic qualities were assessed by the PRISMA (27 items) and AMSTAR (11 items) checklists, respectively. Independent predictive factors associated with these two qualities were evaluated by univariate and multivariate analyses. RESULTS: Hundred ninety-seven meta-analyses representing 10 surgical subspecialties were included. The mean PRISMA and AMSTAR adherences (by items) were 22.2 ± 2.4 and 7.8 ± 1.2, respectively, and a positive linear correlation was found between them with an R(2) of 0.793. Those meta-analyses conducted by the first authors having meta-analysis publication previously had significantly higher reporting and methodologic qualities than those who did not (P = 0.002 and P = 0.001). Meanwhile, there were also significant differences in these two qualities between studies published in Q1-ranked and (Q2 + Q3)-ranked journals as rated by the SCImago indicator (P < 0.001 and P < 0.001). On multivariate analyses, region of origin (non-Asia vs. Asia), publishing experience of first authors (ever vs. never), rank of publishing journals (Q1 vs. Q2 + Q3), and preregistration (presence vs. absence) were independently associated with superior reporting and methodologic qualities. CONCLUSIONS: The reporting and methodologic qualities of current surgical meta-analyses remained suboptimal, and first authors' experience and ranking of publishing journals were independently associated with both qualities. Preregistration might be an effective measure to improve the quality of meta-analyses, which deserves more attention from future study conductors.

Tumor size does not independently affect long-term survival after curative resection of solitary hepatocellular carcinoma without macroscopic vascular invasion.

OBJECTIVE: The aim of this study was to investigate the prognostic value of tumor size alone on long-term survival and recurrence after curative resection for solitary hepatocellular carcinoma (HCC) without macroscopic vascular invasion. METHODS: A single-center cohort of 615 patients with solitary HCC (a single tumor, without macroscopic vascular invasion or distant metastasis) undergoing curative hepatic resection from 2002 to 2010 was retrospectively studied. Using 2.0, 3.0, 4.0, 5.0, 8.0, and 10.0 cm as cut-off values of tumor size, the overall survival (OS) and recurrence-free survival (RFS) rates were compared between the groups of patients with tumor size up to a certain cut-off value and the groups of patients with tumor size above that cut-off value. Thus, multiple comparisons were done. The prognostic factors of OS and RFS were evaluated using univariate and multivariate analyses. RESULTS: The median tumor size of all HCCs was 4.0 cm (range 0.9-22.0 cm). The in-hospital mortality rate was 1.0 %, and the overall morbidity rate was 22.3 %. The 1-, 3-, and 5-year OS rates were 96.0, 79.8, and 69.9 %, and the corresponding RFS rates were 83.6, 72.7, and 57.2 %, respectively. On univariate analyses, the 1-, 3-, and 5-year OS and RFS rates were significantly different between the individual two groups of patients as divided by the aforementioned different cut-off values of tumor sizes (all p < 0.05). However, when tumor size was put as a continuous variable into multivariate analysis, it was no longer an independent prognostic factor of OS or RFS after curative resection. CONCLUSIONS: Tumor size did not independently affect long-term survival and recurrence after curative resection of solitary HCC without macroscopic vascular invasion. Therefore, there is no size limit that precludes hepatic resection for solitary HCC, provided the tumor is resectable.