Genomic profiling of esophageal squamous cell carcinoma (ESCC)—Basis for precision medicine

Prognostic value of circulating tumour DNA during post-radiotherapy surveillance in locally advanced esophageal squamous cell carcinoma

BACKGROUND

The potential of circulating tumour DNA (ctDNA) as a reliable biomarker for relapse/metastasis early detection and prognosis in esophageal squamous cell carcinoma (ESCC) after radiotherapy/chemoradiotherapy (RT/CRT) initiation requires comprehensive investigation.

METHODS

Treatment-naive locally advanced ESCC patients with available baseline plasma samples were prospectively enrolled from November 2018 to January 2020. RT/CRT was delivered with a simultaneous integrated boost of radiation dose. Serial plasma samples were collected at baseline (T0 ), week 4 of RT/CRT (T1 ), 1-3 (T2 ) and 3-6 months post-RT/CRT (T3 ). ctDNA was analysed using next-generation sequencing of 474 cancer-relevant genes.

RESULTS

A total of 128 plasma samples from 40 eligible patients were analysed (median age: 64 [range: 40-78], 88% males, 95% stage III/IV), and the median follow-up time was 20.6 months (range: 12.2-33.3). During the post-RT/CRT surveillance including 36 patients, radiological progression was observed in 16 patients, and 69% (11/16) had detectable post-RT/CRT ctDNA prior to radiological progression, with a median lead time of 4.4 months compared with radiological imaging. ctDNA positivity at T1 (hazard ratio, HR: 3.60, 95% confidence interval, CI: 1.30-10.01) or T2 (HR: 5.45, 95% CI: 1.72-17.26) indicated inferior progression-free survival (PFS). ctDNA clearance between T0 -T1 (HR: 0.31, 95% CI: 0.08-1.13) or T0 -T2 (HR: 0.11; 95% CI: 0.02-0.61) was associated with relatively favourable PFS. Similar results were obtained when focusing on patients without esophagectomy after RT/CRT. Notably, detectable ctDNA at T1 was a potential indicator of high local recurrence risks (HR: 4.43, 95% CI: 1.31-15.04).

CONCLUSIONS

ctDNA was identified as a robust biomarker for early detection of disease progression and post-RT/CRT prognosis stratification in ESCC. Detectable ctDNA at week 4 of RT/CRT might indicate higher local recurrence risks, implying the potential clinical utility of ctDNA tests in guiding post-RT/CRT treatments for locoregional control in ESCC.

Exploiting the Molecular Basis of Oesophageal Cancer for Targeted Therapies and Biomarkers for Drug Response: Guiding Clinical Decision-Making

Worldwide, oesophageal cancer is the sixth leading cause of deaths related to cancer and represents a major health concern. Sub-Saharan Africa is one of the regions of the world with the highest incidence and mortality rates for oesophageal cancer and most of the cases of oesophageal cancer in this region are oesophageal squamous cell carcinoma (OSCC). The development and progression of OSCC is characterized by genomic changes which can be utilized as diagnostic or prognostic markers. These include changes in the expression of various genes involved in signaling pathways that regulate pathways that regulate processes that are related to the hallmarks of cancer, changes in the tumor mutational burden, changes in alternate splicing and changes in the expression of non-coding RNAs such as miRNA. These genomic changes give rise to characteristic profiles of altered proteins, transcriptomes, spliceosomes and genomes which can be used in clinical applications to monitor specific disease related parameters. Some of these profiles are characteristic of more aggressive forms of cancer or are indicative of treatment resistance or tumors that will be difficult to treat or require more specialized specific treatments. In Sub-Saharan region of Africa there is a high incidence of viral infections such as HPV and HIV, which are both risk factors for OSCC. The genomic changes that occur due to these infections can serve as diagnostic markers for OSCC related to viral infection. Clinically this is an important distinction as it influences treatment as well as disease progression and treatment monitoring practices. This underlines the importance of the characterization of the molecular landscape of OSCC in order to provide the best treatment, care, diagnosis and screening options for the management of OSCC.

PI3K/Akt/mTOR Signaling Pathway: Role in Esophageal Squamous Cell Carcinoma, Regulatory Mechanisms and Opportunities for Targeted Therapy

Esophageal squamous cell carcinoma (ESCC), is the most common type of esophageal cancer worldwide, mainly occurring in the Asian esophageal cancer belt, including northern China, Iran, and parts of Africa. Phosphatidlinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway is one of the most important cellular signaling pathways, which plays a crucial role in the regulation of cell growth, differentiation, migration, metabolism and proliferation. In addition, mutations in some molecules of PI3K/Akt/mTOR pathway are closely associated with survival and prognosis in ESCC patients. A large number of studies have found that there are many molecules in ESCC that can regulate the PI3K/Akt/mTOR pathway. Overexpression of these molecules often causes aberrant activation of PI3K/Akt/mTOR pathway. Currently, several effective PI3K/Akt/mTOR pathway inhibitors have been developed, which can play anticancer roles either alone or in combination with other inhibitors. This review mainly introduces the general situation of ESCC, the composition and function of PI3K/Akt/mTOR pathway, and regulatory factors that interact with PI3K/Akt/mTOR signaling pathway. Meanwhile, mutations and inhibitors of PI3K/Akt/mTOR pathway in ESCC are also elucidated.

Selected updates in molecular and genomic pathology of esophageal cancer

Recent years have seen rapid advances in the field of molecular and genomic pathology that have not only improved understanding of esophageal carcinogenesis and tumor immune environment in general but also have reshaped pathology practice and clinical management. In this article, we provide updates on three topics (1) human epidermal growth factor receptor 2, the first and most important biomarker in targeted therapy of esophageal cancer; (2) programmed death 1/programmed death ligand 1, recent biomarkers that have shown promise in treating both esophageal adenocarcinoma and esophageal squamous cell carcinoma; and (3) human papillomavirus involvement in esophageal carcinogenesis, one of the most debated topics in the field, discussed here with a renewed understanding from recent genomic and molecular data.

Local and Systemic Interleukin-32 in Esophageal, Gastric, and Colorectal Cancers: Clinical and Diagnostic Significance

Little is known on clinical and diagnostic relevance of interleukin-32 in gastrointestinal tract (GIT) cancers. We determined its mRNA (n = 52) and protein (n = 63) expression in paired (tumor-normal) samples from esophageal squamous cell carcinoma (ESCC) and gastric (GC) and colorectal cancer (CRC) patients, with reference to cancer-associated genes, and quantified circulating interleukin-32 in 70 cancer patients and 28 controls. IL32 expression was significantly upregulated solely in ESCC, reflecting T stage in non-transformed tumor-adjacent tissue. Fold-change in IL32 and IL-32 was higher in left-sided CRC, owing to high interleukin expression in non-transformed right-sided colonic mucosa. IL32 was independently and positively associated with Ki67, HIF1A, and ACTA2 and negatively with TJP1 in tumors and with IL10Ra and BCLxL in non-transformed tumor-adjacent tissue. IL-32 protein was significantly upregulated in colorectal tumors. In ESCC, advanced stage and lymph node metastasis were associated with significant IL-32 upregulation. Circulating interleukin was significantly elevated in cancer patients, more so in ESCC and GC than CRC. As biomarker, IL-32 detected gastroesophageal cancers with 99.5% accuracy. In conclusion, IL-32 is upregulated in GIT cancers at local and systemic level, reflecting hypoxia and proliferative and invasive/metastatic capacity in tumors and immunosuppressive and antiapoptotic potential in non-transformed mucosa, while being an accurate biomarker of gastroesophageal cancers.

Genetic Heterogeneity of Esophageal Squamous Cell Carcinoma with Inherited Family History

Background

Esophageal squamous cell carcinoma (ESCC) is a common malignant tumor with significant geographical variation and familial aggregation. However, the potentially different mechanisms underlying tumorigenesis in patients with ESCC with and without a family history of the disease remain unclear. In this study, the genes mutated in familial and nonfamilial ESCC were analyzed. Further, we aimed to explore the genes related to ESCC and attempt to identify potential patients in families with a history of ESCC.

Methods

Next-generation sequencing technology was used to examine germline mutations and mutation profiles in 36 matched tumor-normal ESCC specimens. Additionally, tumor mutational burden (TMB) values were measured in two cohorts.

Results

We identified four novel germline mutations in patients with familial ESCC, in BAX (c.121dupG: p.E41G), CDKN2A (c.374dupA: p.D125E), TP53 (c.856G>A: p.E286K), and CHEK1 (c.923+1G>A). Mutation profiles revealed that patients with and without a family history of ESCC had similar high-frequency gene mutation profiles, among which TP53 was the most commonly mutated gene. Additionally, tumor-specific mutated genes in patients with a positive family history of ESCC were APC, AKT3, DPYD, EP300, NFE2L2, PPP2R1A, RUNX1, and VEGFA, while those in patients without a family history of ESCC were CXCR4, PIK3R2, SMARCA4, and TTF1. Moreover, patients with positive family history had significantly higher TMB values (7.8 ± 4.1 vs 5.0 ± 2.4, for patients with and without a family history, respectively; P = 0.038).

Conclusion

Our results identified mutation profiles in patients with familial and nonfamilial ESCC, and identified germline mutations in patients with positive history. TMB values may be informative for immunotherapy approaches in familial ESCC.

Role of precision imaging in esophageal cancer

Esophageal cancer is a major cause of morbidity and mortality worldwide. Recent advancements in the management of esophageal cancer have allowed for earlier detection, improved ability to monitor progression, and superior treatment options. These innovations allow treatment teams to formulate more customized management plans and have led to an increase in patient survival rates. For example, in order for the most effective management plan to be constructed, accurate staging must be performed to determine tumor resectability. This article reviews the multimodality imaging approach involved in making a diagnosis, staging, evaluating treatment response and detecting recurrence in esophageal cancer.

Esophageal Squamous Cell Carcinoma Is Accompanied by Local and Systemic Changes in L-arginine/NO Pathway

The L-arginine/NO pathway holds promise as a source of potential therapy target and biomarker; yet, its status and utility in esophageal squamous cell carcinoma (ESCC) is unclear. We aimed at quantifying pathway metabolites in sera from patients with ESCC (n = 61) and benign conditions (n = 62) using LC-QTOF-MS and enzyme expression in esophageal tumors and matched noncancerous samples (n = 40) using real-time PCR with reference to ESCC pathology and circulating immune/inflammatory mediators, quantified using Luminex xMAP technology. ESCC was associated with elevated systemic arginine and asymmetric dimethylarginine. Citrulline decreased and arginine bioavailability increased along with increasing ESCC advancement. Compared to adjacent tissue, tumors overexpressed ODC1, NOS2, PRMT1, and PRMT5 but had downregulated ARG1, ARG2, and DDAH1. Except for markedly higher NOS2 and lower ODC1 in tumors from M1 patients, the pathology-associated changes in enzyme expression were subtle and present also in noncancerous tissue. Both the local enzyme expression level and systemic metabolite concentration were related to circulating inflammatory and immune mediators, particularly those associated with eosinophils and those promoting viability and self-renewal of cancer stem cells. Metabolic reprogramming in ESCC manifests itself by the altered L-arginine/NO pathway. Upregulation of PRMTs in addition to NOS2 and ODC1 and the pathway link with stemness-promoting cytokines warrants further investigation.

Anlotinib Combined With Chemoradiotherapy Exhibits Significant Therapeutic Efficacy in Esophageal Squamous Cell Carcinoma

Objective: The aim of this study was to evaluate the safety and efficacy of anlotinib combined with chemoradiotherapy for treating esophageal squamous cell carcinoma (ESCC) using patient-derived xenografts (PDXs). Methods: PDX-bearing mice were randomly divided into five groups, as follows: control group receiving normal saline, the group receiving radiotherapy, the group receiving cisplatin combined with radiotherapy, the group receiving anlotinib combined with radiotherapy, and the group receiving anlotinib, and cisplatin combined with radiotherapy. Tumor volumes and body weights were measured three times weekly for 2 weeks. The PDXs were initially assessed by comparing the histology of the original patient tumor tissues with that of the corresponding serially passaged xenografts by hematoxylin and eosin (H&E) and P63 staining. Then, expression of Bax, c-PARP, PCNA, and CD31 was detected using immunohistochemistry, and apoptosis was detected by a TUNEL assay. Cytokines released into plasma were analyzed using protein chip technology. Finally, two case studies of ESCC patients were presented to further verify the results observed in the PDX models. Results: The pathological characteristics of the serially passaged patient tumor-derived xenografts established in our study were in line with those of the original ESCC patient samples. The group receiving anlotinib and cisplatin plus radiotherapy exhibited the strongest antitumor response among the groups. Moreover, the ideal anticancer effects of anlotinib combined with chemoradiotherapy observed in clinical patients were consistent with the results observed in the PDX models, and no serious side effects were observed during treatment. Conclusions: Combination therapy with anlotinib and chemoradiotherapy may be an effective regimen for the treatment of advanced ESCC.

Identification of methylated-differentially expressed genes and pathways in esophageal squamous cell carcinoma

Methylation, as an epigenetic modification, can affect gene expression and play a role in the occurrence and development of cancer. This research is devoted to discover methylated-differentially expressed genes (MDEGs) in esophageal squamous cell carcinoma (ESCC) and explore special associated pathways. We downloaded GSE51287 methylation profiles and GSE26886 expression profiles from GEO DataSets, and performed a comprehensive bioinformatics analysis. Totally, 19 hypermethylated, lowly expressed genes (Hyper-LGs) were identified, and involved in regulation of cell proliferation, phosphorus metabolic process and protein kinase activity. Meanwhile, 17 hypomethylated, highly expressed genes (Hypo-HGs) were participated in collagen catabolic process, metallopeptidase and cytokine activity. Pathway analysis determined that Hyper-LGs were enriched in arachidonic acid metabolism pathway, while Hypo-HGs were primarily associated with the cytokine-cytokine receptor interaction pathway. IL 6, MMP3, MMP9, SPP1 were identified as hub genes based on the PPI network that combined 7 ranked methods included in cytoHubba, and verification was performed in human tissues. Our integrated analysis identified many novel genetic lesions in ESCC and provides a crucial molecular foundation to improve our understanding of ESCC. Hub genes, including IL 6, MMP3, MMP9 and SPP1, could be considered for use as aberrant methylation-based biomarkers to facilitate the accurate diagnosis and therapy of ESCC.

Rap1A promotes esophageal squamous cell carcinoma metastasis through the AKT signaling pathway

Ras‑associated protein 1A (Rap1A) is a member of the Ras subfamily of small GTP‑binding proteins and is found to promote metastasis in several types of cancer. However, the functional role and molecular mechanism of action in Rap1A in esophageal squamous cell carcinoma (ESCC) is not fully understood. In the present study, Rap1A was found to be upregulated in ESCC tissues and its expression was correlated with cancer stage. Functional studies revealed that Rap1A could promote ESCC metastasis by stimulating cell migration and invasion in vivo and in vitro. Further study indicated that the transcriptional factor SP1 increased Rap1A expression via promoter binding and transcription activation. Furthermore, Rap1A promoted epithelial‑to‑mesenchymal transition, possibly through the AKT signaling pathway. Hence, the findings of the present study indicated that Rap1A may be a potential prognostic marker or therapeutic target for ESCC.

mTOR: Role in cancer, metastasis and drug resistance

Mammalian target of rapamycin (mTOR) is a serine/threonine kinase that gets inputs from the amino acids, nutrients, growth factor, and environmental cues to regulate varieties of fundamental cellular processes which include protein synthesis, growth, metabolism, aging, regeneration, autophagy, etc. The mTOR is frequently deregulated in human cancer and activating somatic mutations of mTOR were recently identified in several types of human cancer and hence mTOR is therapeutically targeted. mTOR inhibitors were commonly used as immunosuppressors and currently, it is approved for the treatment of human malignancies. This review briefly focuses on the structure and biological functions of mTOR. It extensively discusses the genetic deregulation of mTOR including amplifications and somatic mutations, mTOR-mediated cell growth promoting signaling, therapeutic targeting of mTOR and the mechanisms of resistance, the role of mTOR in precision medicine and other recent advances in further understanding the role of mTOR in cancer.

PIK3CA mutations are frequent in esophageal squamous cell carcinoma associated with chagasic megaesophagus and are associated with a worse patient outcome

Background

Chronic diseases such as chagasic megaesophagus (secondary to Chagas’ disease) have been suggested as etiological factors for esophageal squamous cell carcinoma; however, the molecular mechanisms involved are poorly understood.

Objective

We analyzed hotspot PIK3CA gene mutations in a series of esophageal squamous cell carcinomas associated or not with chagasic megaesophagus, as well as, in chagasic megaesophagus biopsies. We also checked for correlations between the presence of PIK3CA mutations with patients’ clinical and pathological features.

Methods

The study included three different groups of patients: i) 23 patients with chagasic megaesophagus associated with esophageal squamous cell carcinoma (CM/ESCC); ii) 38 patients with esophageal squamous cell carcinoma not associated with chagasic megaesophagus (ESCC); and iii) 28 patients with chagasic megaesophagus without esophageal squamous cell carcinoma (CM). PIK3CA hotspot mutations in exons 9 and 20 were evaluated by PCR followed by direct sequencing technique.

Results

PIK3CA mutations were identified in 21.7% (5 out of 23) of CM/ESCC cases, in 10.5% (4 out of 38) of ESCC and in only 3.6% (1 case out of 28) of CM cases. In the CM/ESCC group, PIK3CA mutations were significantly associated with lower survival (mean 5 months), when compared to wild-type patients (mean 2.0 years). No other significant associations were observed between PIK3CA mutations and patients’ clinical features or TP53 mutation profile.

Conclusion

This is the first report on the presence of PIK3CA mutations in esophageal cancer associated with chagasic megaesophagus. The detection of PIK3CA mutations in benign chagasic megaesophagus lesions suggests their putative role in esophageal squamous cell carcinoma development and opens new opportunities for targeted-therapies for these diseases.