Serum tumor markers and testicular germ cell tumors: a primer for radiologists

Mediastinal Mass as an Initial Presentation of Acute Myeloid Leukemia in a Young Man

A 29-year-old male, hemodynamically stable, presented with chest pain radiating to the interscapular region, with no fever, cough, dyspnea, or other constitutional symptoms. He had right cervical lymphadenopathy on physical examination. Investigations revealed a 3.1 cm anterior mediastinal nodular mass, peripheral immature blood cells, and thrombocytopenia. Bone marrow core biopsy findings were consistent with acute myeloid leukemia (AML). The mediastinal mass was resected via robotic-assisted thoracoscopic surgery. Histopathology revealed involvement of the mediastinal adipose tissue with myeloid sarcoma. Molecular testing showed TP53 mutation, signifying a poor prognosis. The patient failed several lines of therapy and expired. This case demonstrates an atypical presentation of AML and emphasizes the criticality of early detection in individuals who do not exhibit the usual symptoms associated with the disease. The presence of immature cell lines in peripheral blood should prompt an investigation to determine bone marrow involvement in an otherwise healthy young adult.

Advances in biomarker discovery using circulating cell-free DNA for early detection of hepatocellular carcinoma

The past several decades have witnessed unprecedented progress in basic and clinical cancer research, and our understanding of the molecular mechanisms and pathogenesis of cancers have been greatly improved. More recently, with the availability of high-throughput sequencing and profiling platforms as well as sophisticated analytical tools and high-performance computing capacity, there have been tremendous advances in the development of diagnostic approaches in clinical oncology, especially the discovery of novel biomarkers for cancer early detection. Although tissue biopsy-based pathology has been the "gold standard" for cancer diagnosis, notable limitations such as the risk due to invasiveness and the bias due to intra-tumoral heterogeneity have limited its broader applications in oncology (e.g., screening, regular disease monitoring). Liquid biopsy analysis that exploits the genetic and epigenetic information contained in DNA/RNA materials from body fluids, particularly circulating cell-free DNA (cfDNA) in the blood, has been an intriguing alternative approach because of advantageous features such as sampling convenience and minimal invasiveness. Taking advantage of innovative enabling technologies, cfDNA has been demonstrated for its clinical potential in cancer early detection, including hepatocellular carcinoma (HCC), the most common liver cancer that causes serious healthcare burden globally. Hereby, we reviewed the current advances in cfDNA-based approaches for cancer biomarker discovery, with a focus on recent findings of cfDNA-based early detection of HCC. Future clinical investigations and trials are warranted to further validate these approaches for early detection of HCC, which will contribute to more effective prevention, control, and intervention strategies with the ultimate goal of reducing HCC-associated mortality. This article is categorized under: Cancer > Genetics/Genomics/Epigenetics.

Immune-related mechanisms and immunotherapy in extragonadal germ cell tumors

Purpose of review

Extragonadal germ cell tumors (EGCTs) are relatively rare tumors, accounting for 1%-5% of all GCTs. In this review, we summarize the current research progress regarding the pathogenesis, diagnosis, and treatment of EGCTs from an immunology perspective.

Recent findings

The histological origin of EGCTs is related to a gonadal origin, but they are located outside the gonad. They show great variation in morphology and can occur in the cranium, mediastinum, sacrococcygeal bone, and other areas. The pathogenesis of EGCTs is poorly understood, and their differential diagnosis is extensive and challenging. EGCT behavior varies greatly according to patient age, histological subtype, and clinical stage.

Summary

This review provides ideas for the future application of immunology in the fight against such diseases, which is a hot topic currently.

Testicular Germ Cell Tumors: Classification, Pathologic Features, Imaging Findings, and Management

Testicular germ cell tumors (TGCTs) demonstrate a wide variety of histopathologic, genetic, pathogenetic, and immunocytochemical characteristics and various clinical-biologic profiles and prognoses. Most TGCTs arise from an intratubular precursor cell referred to as germ cell neoplasia in situ (GCNIS), which is an embryonic germ cell with the potential to differentiate into a plethora of embryonic and extraembryonic lineages. Advances in pathologic examination and genetics paved the way for the 2016 World Health Organization (WHO) classification system, which recognizes two pathogenetically distinct groups of TGCTs. Although postpubertal tumors originate from GCNIS, almost all prepubertal tumors belong to the non-GCNIS category. Molecular testing for chromosome 12p amplification helps to distinguish the two tumor categories. Imaging techniques such as US, CT, MRI, and fluorine 18 (¹⁸F)-fluorodeoxyglucose PET/CT are pivotal to the diagnosis and staging, evaluation of complications and treatment response, and long-term surveillance of TGCTs. In addition, select MRI findings may help to differentiate a seminoma from a nonseminomatous mixed TGCT. Accurate diagnosis of TGCTs has therapeutic and prognostic implications. Although seminomas show exquisite response to chemotherapy and radiation therapy, postpubertal teratomas are highly resistant to both. The 2016 WHO classification system introduced changes in the diagnosis and management of TGCTs, including the development of new treatment and follow-up guidelines. Radiologists play an essential role in the optimal treatment of patients with TGCTs. Online supplemental material is available for this article. ©RSNA, 2021.

Profiling of Serum Extracellular Vesicles Reveals miRNA-4525 as a Potential Biomarker for Advanced Renal Cell Carcinoma

AIM

To identify novel diagnostic markers for renal cell carcinoma (RCC), we analyzed miRNAs in serum extracellular vesicles (EVs).

MATERIALS AND METHODS

EVs were purified from serum of healthy controls and patients with localized and advanced RCC using T-cell immunoglobulin domain and mucin domain-containing protein 4 conjugated to magnetic beads. miRNA profiling of EVs was conducted by microarray analysis. miRNA expression was examined by quantitative reverse transcription-polymerase chain reaction. Lastly, proteomic analysis of RCC cells transfected with a miRNA inhibitor was performed to identify its potential targets.

RESULTS

Microarray analysis revealed that nine miRNAs were increased by more than 1.5-fold in EVs from patients with RCC. Among them, miRNA-4525 was significantly elevated; miRNA-4525 expression was higher in RCC tissue than in the adjacent normal tissue. Proteomic analysis identified alpha fetoprotein and albumin as its potential targets.

CONCLUSION

These findings suggest the potential of miRNA-4525 in serum EVs as a novel biomarker for advanced RCC.

RNA-Binding Proteins Play an Important Role in the Prognosis of Patients With Testicular Germ Cell Tumor

Testicular germ cell tumors (TGCTs) are common urological neoplasms in young adult males. The outcome of TGCT depends on pathologic type and tumor stage. RNA-binding proteins (RBPs) influence numerous cancers via post-transcriptional regulation. The prognostic importance of RBPs in TGCT has not been fully investigated. In this study, we set up a prognostic risk model of TGCT using six significantly differentially expressed RBPs, namely, TRMT61A, POLR2J, DIS3L2, IFIH1, IGHMBP2, and NPM2. The expression profiles were downloaded from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression datasets. We observed by performing least absolute shrinkage and selection operator (LASSO) regression analyses that in the training cohort, the expression of six RBPs was correlated with disease-free survival in patients with TGCT. We assessed the specificity and sensitivity of 1-, 3-, 5-, and 10-year survival status prediction using receiver operating characteristic curve analysis and successfully validated using the test cohorts, the entire TCGA cohort, and Gene Expression Omnibus (GEO) datasets. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and gene set enrichment analyses were carried out to seek the possible signaling pathways related with risk score. We also examined the association between the model based on six RBPs and different clinical characteristics. A nomogram was established for TGCT recurrence prediction. Consensus clustering analysis was carried out to identify the clusters of TGCT with different clinical outcomes. Ultimately, external validations of the six-gene risk score were performed by using the GSE3218 and GSE10783 datasets downloaded from the GEO database. In general, our study constructed a prognostic model based on six RBPs, which could serve as independent risk factor in TGCT, especially in seminoma, and might have brilliant clinical application value.

Lung neoplasm mimicking as ectopic pregnancy due to paraneoplastic secretion of human chorionic gonadotropin: a case report and literature review

PURPOSE

The present systematic review aimed to examine the relationship between lung neoplasm and human chorionic gonadotropin (HCG). Especially, women with lung neoplasm mimicking as ectopic pregnancy were explored.

METHODS

A rare case of lung neoplasm with high serum β-HCG, which was initially thought to be ectopic pregnancy, was reported. A literature search was performed of the US National Library of Medicine (MEDLINE), EMBASE, PubMed, and the Cochrane Database of Systematic Reviews using appropriate keywords and subject headings to February 2020.

RESULTS

Studies assessed lung neoplasm patients with positive HCG were included. Twenty studies, including 24 patients, were included. These cases illustrate the importance of considering the possibility of paraneoplastic secretion of β-HCG in patients who have a positive pregnancy test. This may prevent a delay in the diagnosis and treatment of malignancy in young women. Of the 24 cases, only 7 (29.17%) were managed surgically; others were managed conservatively or with chemotherapy or radiation.

CONCLUSION

The present systematic review shows the need to re-awaken awareness and high index of suspicion to lung neoplasm diagnosis in patients with positive pregnancy test.

Multimodality Radiological Pictorial Review of Testicular Carcinoma: From Initial Staging to Restaging

With an overall 5-year survival rate >95%, patients with testicular cancer have a great prognosis. Although initial diagnosis is based on clinical examination, imaging does play a significant role in the diagnosis and prognosis of testicular cancer, which are dependent on tumor burden and staging. Successful treatment requires appropriate disease assessment throughout a patient’s treatment: evaluating treatment response, restaging, and monitoring for disease recurrence after treatment completion. Ultrasound is usually the initial screening modality for painless testicular masses, and computedtomography (CT) the most commonly used for staging and restaging. However, with regard to seminomas, positron-emission tomography (PET) combined with CT is slowly taking priority. With regard to nonseminomatous germ-cell tumors, PET-CT has not proven to be completely effective, due to a high number of false-negative results. The purpose of this paper is to provide radiologists with a pictorial review of testicular carcinoma from initial staging through posttreatment follow-up.

A phase 1 study of combined guadecitabine and cisplatin in platinum refractory germ cell cancer

Purpose

Germ cell tumors (GCTs) are cured with therapy based on cisplatin, although a clinically significant number of patients are refractory and die of progressive disease. Based on preclinical studies indicating that refractory testicular GCTs are hypersensitive to hypomethylating agents (HMAs), we conducted a phase I trial combining the next‐generation HMA guadecitabine (SGI‐110) with cisplatin in recurrent, cisplatin‐resistant GCT patients.

Methods

Patients with metastatic GCTs were treated for five consecutive days with guadecitabine followed by cisplatin on day 8, for a 28‐day cycle for up to six cycles. The primary endpoint was safety and toxicity including dose‐limiting toxicity (DLT) and maximum tolerated dose (MTD).

Results

The number of patients enrolled was 14. The majority of patients were heavily pretreated. MTD was determined to be 30 mg/m² guadecitabine followed by 100 mg/m² cisplatin. The major DLTs were neutropenia and thrombocytopenia. Three patients had partial responses by RECIST criteria, two of these patients, including one with primary mediastinal disease, completed the study and qualified as complete responses by serum tumor marker criteria with sustained remissions of 5 and 13 months and survival of 16 and 26 months, respectively. The overall response rate was 23%. Three patients also had stable disease indicating a clinical benefit rate of 46%.

Conclusions

The combination of guadecitabine and cisplatin was tolerable and demonstrated activity in patients with platinum refractory germ cell cancer.

Tumour markers and their utility in imaging of abdominal and pelvic malignancies

The utility of tumour biomarkers has increased considerably in the era of personalised medicine and individualised therapy in oncology. Biomarkers may be prognostic or predictive, and only a handful of markers are currently US Food and Drug Administration (FDA)-approved for clinical use. Tumour markers have a wide array of uses such as screening, establishing a differential diagnosis, assessing risk, prognosis, and treatment response, as well as monitoring disease status. Major overlap exists between biomarkers and their associated pathologies; therefore, despite suggestive imaging features, establishing a differential diagnosis may be challenging for the radiologist. We review common biomarkers that are of interest to radiologists such as carcinoembryonic antigen (CEA), lactate dehydrogenase (LDH), prostate-specific antigen (PSA), beta human chorionic gonadotropin (β-hCG), carbohydrate antigen 19-9 (CA 19-9), alpha fetoprotein (AFP), and carbohydrate or cancer antigen 125 (CA 125), as well as their associated malignant and non-malignant pathologies. We also present relevant case examples from our practice.

Imaging of scrotal masses

Testicular cancer is responsible for approximately 0.1% of all cancer deaths in the USA, and seminoma is the most common type of testicular tumor. Ultrasonography is the primary imaging modality for accessing testicular and extratesticular lesions, while magnetic resonance imaging can be used for problem solving in lesion characterization in certain cases. CT imaging is usually performed for retroperitoneal staging of testicular cancer metastasis and follow-up after treatment. Extratesticular masses are common, yet rarely malignant. Imaging plays an important role in primary diagnosis of testicular cancer and differentiating it from common non-neoplastic findings. The purpose of this article is to review various imaging findings in testicular and extratesticular masses.