Epstein-Barr virus association with early cancers found together with gastric medullary carcinomas demonstrating lymphoid infiltration

Colorectal medullary carcinoma: a pathological subtype with intense immune response and potential to benefit from immune checkpoint inhibitors

INTRODUCTION

Different pathological types of colorectal cancer have distinguished immune landscape, and the efficacy of immunotherapy will be completely different. Colorectal medullary carcinoma, accounting for 2.2-3.2%, is characterized by massive lymphocyte infiltration. However, the attention to the immune characteristics of colorectal medullary carcinoma is insufficient.

AREA COVERED

We searched the literature about colorectal medullary carcinoma on PubMed through November 2023to investigate the hallmarks of colorectal medullary carcinoma's immune landscape, compare medullary carcinoma originating from different organs and provide theoretical evidence for precise treatment, including applying immunotherapy and BRAF inhibitors.

EXPERT OPINION

Colorectal medullary carcinoma is a pathological subtype with intense immune response, with six immune characteristics and has the potential to benefit from immunotherapy. Mismatch repair deficiency, ARID1A missing and BRAF V600E mutation often occurs. IFN-γ pathway is activated and PD-L1 expression is increased. Abundant lymphocyte infiltration performs tumor killing function. In addition, BRAF mutation plays an important role in the occurrence and development, and we can consider the combination of BRAF inhibitors and immunotherapy in patients with BRAF mutant. The exploration of colorectal medullary carcinoma will arouse researchers' attention to the correlation between pathological subtypes and immune response, and promote the process of precise immunotherapy.

Integrated assessment of PD-L1 expression and molecular classification facilitates therapy selection and prognosis prediction in gastric cancer

Purpose

Targeting the PD-1/PD-L1 pathway has emerged as a novel therapy for cancer. To identify rational candidates for anti-PD-1/PD-L1 immunotherapy in gastric cancer (GC), the abundance of PD-L1 expression was evaluated on a kind of biomarker-based molecular classification for shaping prognosis and treatment planning.

Methods

One hundred and sixty-five GCs were classified into five subgroups using immunohistochemistry (IHC) and in situ hybridization (ISH) methods, based on a panel of seven markers (MLH1, PMS2, MSH2, MSH6, E-cadherin, P53, and Epstein-Barr virus mRNA). The expression of PD-L1 in GC tissues was analyzed immunohistochemically.

Results

The five categories (Epstein-Barr virus positivity, microsatellite instability, aberrant E-cadherin, aberrant P53 expression, and normal P53 expression) correspond to the reported molecular subgroups for similar proportions and clinicopathologic characteristics. Survival analysis indicated that subgroups with aberrant E-cadherin expression independently predicted a worse prognosis in GC patients (HR=2.51, P=0.010). The clinical and prognostic profiles produced by this stratification in nonintestinal-type GC were distinguishable from those in intestinal-type. Although PD-L1 was not a significant prognostic factor, that more frequent presence of PD-L1-positive in microsatellite instability tumors than other subtypes (P<0.010) hinted at a prolonged clinical course. Moreover, the lowest level of PD-L1 but the highest of Her2 was observed in the group of aberrant P53, namely it was suggested that there was a negative correlation between PD-L1 and Her2 overexpression.

Conclusion

Different molecular subtypes in GC may have a tendency to react differently to anti-PD-L1/PD-1 immunotherapy or anti-Her2 therapy. A combination of PD-L1 expression and this cost-effective classification strategy would be helpful for predicting prognosis and promoting personalized therapy in clinical practice.

Detection of Epstein-Barr virus Genome in Squamous Cell Carcinomas of the Larynx

Epstein-Barr virus (EBV) is a B-lymphotropic virus with a tumorigenic potential. EBV infection has been recognized as the main cause of nasopharyngeal carcinoma and Burkitt's lymphoma. The aim of our study was to determine the incidence of EBV in squamous cell carcinomas of the larynx. We employed for our analysis a sensitive polymerase chain reaction (PCR) assay, followed by restriction fragment length polymorphism (RFLP) for further confirmation of the specificity of the PCR-amplification reaction. Our analysis revealed that 9 of 27 (33%) specimens harbored the EBV genome in the tumor tissue while only 4 (15%) specimens from adjacent normal tissue exhibited evidence of EBV infection. Three were EBV positive for both normal and tumor tissue. No association has been found with disease stage, histological differentiation and nodes at pathology. The relatively high incidence of EBV in the tumor tissue (33%) of patients with laryngeal cancer, as compared to the low (15%) incidence of the virus genome detected in the adjacent normal tissue of the patients, indicates a probable role of EBV in the development of the disease.

High JC virus load in gastric cancer and adjacent non-cancerous mucosa

The JC virus (JCV) infects a large proportion of the worldwide population and approximately 90% of adults are seropositive. Recent reports have described the possibility of its oncogenetic role in several malignancies. The aim of the present study was to assess the oncogenetic significance of JCV for gastric cancer. Twenty-two sample pairs of fresh tumor and adjacent non-cancerous tissue (ANCT) as well as 10 normal gastric mucosa specimens were investigated on the basis of nested polymerase chain reaction (PCR) followed by Southern blotting, DNA direct sequencing, real-time PCR, in situ PCR and immunohistochemistry. The T antigen sequence was detected in 86.4% of gastric cancers and ANCT, and in 100% of the normal mucosa samples, as for virus capsid protein, 54.1%, 68.1% and 70%, respectively. A generally low incidence was noted for agnoprotein. The JCV DNA load was approximately 10-fold higher in both gastric cancers and paired ANCT (4784 +/- 759 and 5394 +/- 1466 copies/microg DNA, respectively) than in normal gastric tissue (542.4 +/- 476.0 copies/microg DNA, P < 0.0001). In situ PCR revealed sporadic JCV genome-positive cancer cells and foveolar epithelial cells. T antigen protein expression assessed by immunohistochemistry was detected only in one case (1/22; 4.5%), probably because the half life of T antigen might be short. It was concluded that the gastric epithelium in most Japanese people is infected with JCV at a low rate but levels of infection are increased markedly in both cancer cells and ANCT, indicating that multiplication of JCV copies might be a risk factor and a background for gastric carcinogenesis.

Epstein-Barr virus in patients with chronic lymphocytic leukemia: a pilot study

The objective of this study was to assess the incidence and the clinical significance of Epstein-Barr virus (EBV) in patients with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). Patients with CLL/SLL who presented at The University of Texas M. D. Anderson Cancer Center over a 2-year period and had available marrow paraffin blocks were studied for evidence of EBV infection using a highly specific in-situ hybridization assay for detection of EBV encoded RNA (EBERs). Results were analysed in relation to other presenting characteristics and outcome. Thirty-two patients were examined. EBERs were detected in the bone marrow of 12 of 32 (38%) CLL/SLL marrows vs 0 of 20 normal marrows (p = 0.002). EBERs were observed in sporadic granulocytes alone or in addition to its presence in lymphocytes in nine of the 12 EBV-positive patients. EBERs were detected less frequently in patients with Rai stage 0 - 1 disease (20%) compared with Rai stage 2 - 4 (66%; p = 0.008). EBER-positive patients tended to have higher lactate dehydrogenase levels (p = 0.053). The 10-year survival rate was 22% vs 58% for patients with and without discernible EBERs (log-rank, p = 0.08). Evidence of EBV infection was found in 38% of patients with CLL/SLL. Despite the small number of patients tested, discernable EBERs were significantly more common in individuals with more advanced Rai stage and there was a trend toward shorter survival in patients in whom EBV EBERs were discerned. Larger studies are needed to determine the prognostic value and role of EBV infection in patients with CLL/SLL.

Gastric cancer mimicking a submucosal tumor diagnosed by laparoscopic excision biopsy

We report a case of advanced gastric cancer exhibiting the features of a submucosal tumor (SMT) of the gastric body. The patient was a 50-year-old male in whom a gastric SMT was detected during a mass screening examination. Upper gastrointestinal endoscopy revealed a protuberant tumor, 2 cm in diameter, covered with normal-appearing mucosa. Examination of an endoscopic biopsy specimen of the tumor revealed chronic gastritis with regenerative and erosive changes. An endoscopic ultrasound examination demonstrated a hypoechoic mass in the third layer of the gastric wall. The clinical diagnosis was gastric SMT, and the patient's course was monitored. Twenty-six months after the initial visit to our hospital, an endosonograph-guided biopsy revealed Group III (borderline lesion). Three months after the biopsy, the size of the SMT had increased slightly. Laparoscopic wedge resection of the tumor was performed to make a pathologic diagnosis and we were able to make a diagnosis of gastric lymphoepithelioma-like carcinoma intraoperatively. Gastrectomy with lymph node dissection was followed as curative surgery. Laparoscopic total excision biopsy is a useful technique in patients with a gastric SMT whose diagnosis has not been confirmed pathologically.

Epstein-Barr virus and gastric carcinoma in Western patients: comparison of pathological parameters and p53 expression in EBV-positive and negative tumours

AIMS

The presence of Epstein-Barr virus (EBV) was studied in 56 gastric carcinomas from Western patients by in-situ hybridization for EBV-encoded RNAs (EBER). EBV-positive and negative carcinomas were compared for various pathological parameters including p53 overexpression.

METHODS AND RESULTS

EBERs transcripts were detected in seven cases overall: four cases of 52 conventional carcinomas (7. 7%) and three cases of four gastric carcinomas with lymphoid stroma (75%). EBER positivity was diffuse in five cases and restricted to a localized area of the tumour in two cases of conventional carcinoma. A monoclonal EBV genomic pattern was demonstrated in the case tested by Southern blot analysis. By immunohistochemical analysis, neither EBV latent or lytic cycle proteins nor C3d/EBV receptor were expressed by neoplastic cells. EBER positivity was significantly correlated with prominent lymphoid reaction (P = 0.0002) which was associated with numerous PS100-positive dendritic cells and with HLA-DR expression by tumour cells (P = 0.03). p53 immunoreactivity in more than 30% of tumour cells was detected in 25 out 49 EBV-negative cases and was absent in EBV-positive cases except in one case with focal EBER-positivity.

CONCLUSIONS

Focal staining for EBER is an unusual finding in the setting of gastric carcinoma and these results suggest that there might be two types of EBV-associated gastric carcinoma in which the viral infection will play a different role. The presence of a stromal lymphoid reaction which is strongly correlated with EBV positivity, is associated with antigen-presenting ability by HLA-DR-positive tumour cells or abundant dendritic cells. The function of p53 appears preserved in all EBV-associated carcinomas except in one case with focal EBER expression whereas the immunohistochemical pattern of p53 is suggestive of a mutational phenomenon in 51% of EBV-negative cases.

Case report: hypoechoic submucosal nodules: a sign of Epstein-Barr virus-associated early gastric cancer

The Epstein-Barr virus (EBV) has been reported to be detectable in about 10% of gastric carcinomas. We performed a comparative study of endosonographic findings of EBV-positive and -negative early gastric carcinomas. Epstein-Barr virus was detected in 11.8% (four of 34) of endosonographically observed early gastric carcinoma lesions. Endoscopic ultrasonography (EUS) revealed a hypoechoic mass in the third layer, which reflected submucosal nodules, in 75% (three of four) of EBV-associated lesions. Endoscopically, in 66.7% (two of three) of EBV-associated carcinomas, the depressed lesion was surrounded by a raised margin covered with normal mucosa and was similar to a submucosal tumour (P < 0.05). Histologically, all three cases of EBV-associated lesions with submucosal tumour invasion had submucosal nodules of carcinoma with lymphoid stroma and 75% (three of four) were located in the gastric body. The ratio of maximal thickness to width of EBV-associated lesions was significantly larger than that of EBV-negative lesions, and this tendency was marked in lesions with submucosal tumour invasion (P < 0.05). This study indicated that EUS and endoscopy are of great use for the determination of EBV association with early gastric carcinoma.

Establishment of Epstein-Barr virus-positive human gastric epithelial cell lines

We have established two Epstein-Barr virus (EBV)-positive cell lines, GT38 and GT39, derived from human gastric tissues of two patients bearing gastric carcinoma. Both cell lines were positive for cytokeratin, an epithelial marker, but not for lymphocyte-related markers. Unlike GT39 cell line, GT38 cells lacked the property of contact inhibition. EBV genome was detected in both cell lines. The cell lines were positive for latent membrane protein 1, and EBV-determined nuclear antigen 1 (EBNA1). EBNA2 was also detected in GT38. These cell lines should be useful for studying the interaction of EBV with gastric epithelial cells and its role in gastric carcinogenesis.

Detection of the Epstein-Barr virus genome in cervical neoplasia is closely related to the degree of infiltrating lymphoid cells: a polymerase chain reaction and in situ hybridization approach

To cast light on the significance of Epstein-Barr virus (EBV) infection in cervical tumorigenesis, 44 cervical intraepithelial neoplasia (CIN) types I/II, and 70 CIN III lesions, 60 invasive squamous cell carcinomas (ISCC), and 20 normal cervical samples were investigated by polymerase chain reaction (PCR) and RNA in situ hybridization (RISH) assays. The EBV genome was detected by PCR using primers targeting the IR region in three (6.8%) of the CIN I/II, 15 (21.4%) of the CIN III and 13 (21.7%) of the ISCC lesions, while using an EBER oligonucleotide probe RISH revealed positive signals in infiltrating lymphocytes located in the cervical stroma, but not in dysplastic or tumor cells. There was a significant correlation between the presence of EBV DNA and the degree of lymphoid cell infiltration (P = 0.0223). In contrast, none of the normal cervical samples that were without inflammation demonstrated any EBV infection. Thus, the results indicated that a positive result for EBV on PCR may be simply dependent on the amount of lymphocytes in cervical stroma, suggesting that this virus does not play a major role in the etiology of cervical neoplasia.

Endoscopic and pathologic features of Epstein-Barr virus-associated gastric carcinoma

BACKGROUND

Although the presence of Epstein-Barr virus has been documented in approximately 7% of patients with gastric carcinoma, the clinical features of Epstein-Barr virus-associated carcinoma have not been well documented. We studied the histologic and endoscopic characteristics of Epstein-Barr virus-associated gastric carcinoma.

METHODS

We tested 124 gastric carcinomas from 117 patients using in situ hybridization for Epstein-Barr virus encoded small RNA1. The histologic and endoscopic findings in the Epstein-Barr virus-associated groups and the negative control groups were analyzed and compared.

RESULTS

Twelve tumors (9.7%) were identified as Epstein-Barr virus associated. These lesions were located mainly in the upper part of the stomach (p < .05) and had a diffuse-type histology (p < .05) compared with those in the control group. Six of seven (85.7%) early Epstein-Barr virus-associated lesions were type 0 IIc (superficial depressed) or a combined type, and 42.9% were accompanied by submucosal nodules of carcinoma with lymphoid stroma. Four of five (80%) advanced Epstein-Barr virus-associated tumors were type 3 (ulcerated without definite limits), thought to be the advanced shape of superficial depressed lesions.

CONCLUSIONS

Epstein-Barr virus-associated gastric carcinomas often appear as superficial depressed or ulcerated lesions in the upper part of the stomach and have a diffuse-type histology with lymphoid infiltration.

Infrequent overexpression of p53 protein in Epstein-Barr virus-associated gastric carcinomas

Epstein-Barr virus (EBV) infection was studied in a total of 412 patients with poorly differentiated gastric adenocarcinoma by in situ hybridization for EBV-encoded small RNA. EBV-specific RNA was detected in tumor cell nuclei of 83 (20.1%) of 412 gastric carcinomas, of which 60 were histologically subclassified as gastric carcinoma with lymphoid stroma (GCLS). All EBV-positive gastric carcinomas as well as 90 randomly selected EBV-negative gastric carcinomas were further studied for p53 protein expression by immunohistochemistry. The overexpression of p53 protein was demonstrated in only 7 (8.4%) of 83 EBV-positive gastric carcinomas. This was in marked contrast to the frequency of 34.4% in EBV-negative gastric carcinomas. In addition, a few p53-positive nuclei were characteristically scattered in the tumors of many EBV-positive GCLS, but this was not regarded as p53 overexpression arising from mutation of the gene. Our findings suggested that EBV-associated gastric carcinomas may arise through a different mechanism from other types of gastric carcinomas without EBV infection.

Detection of Epstein-Barr virus DNA in gastric carcinoma with lymphoid stroma

Gastric carcinoma with lymphoid stroma (GCLS) was considered to be one of the virus-associated neoplasms. However, the precise mechanism of Epstein-Barr virus (EBV) oncogenesis for GCLS remains unclear. We used polymerase chain reaction (PCR) and DNA in situ hybridization (ISH) methods to detect the presence of EBV DNA in 14 cases of gastric carcinoma, including 8 cases of GCLS. Epstein-Barr virus DNA was detected by both PCR and ISH in 3 of the 8 GCLS cases (37.5%) and was negative in the other 6 cases of non-GCLS. In situ DNA hybridization showed that the EBV DNA was in the carcinoma cells in all cases that were positive by PCR. Among the positive cases, one early gastric carcinoma showed that EBV DNA was not only in the carcinoma cells, but also in the normal epithelium. This study provides the interpretation of the finding of EBV DNA in nonneoplastic gastric epithelium. Some genetic changes may be initiated in the EBV-infected nonneoplastic cells, which would lead to oncogenesis.

Apoptosis, proliferative activity and Bcl-2 expression in Epstein-Barr-virus-positive non-Hodgkin's lymphomas

In order to clarify the effects of Epstein-Barr virus (EBV) infection on apoptosis and proliferative activity of non-Hodgkin's lymphoma, 135 Japanese lymphoma cases were investigated for the presence of viral RNA and its correlation with bcl-2 protein (Bcl-2) expression. In addition, the role of EBV in lymphoma-genesis was also studied in terms of EBV genotyping and specific deletion in the gene for the latent membrane protein 1 (LMP-1). EBER-1 RNA in situ hybridization revealed EBV in 18 cases (13.3%), comprising 12 of 44 T cell (27.3%) and 6 of 91 B cell (6.6%) lymphomas. Type A EBV was found in all 18 cases (100%), and 17 of the 17 (100%) evaluable cases showed a 30-bp deletion within the 3' end of LMP-1. Comparison of apoptotic indices (AI), assessed by DNA nick-end labelling, and proliferative activity, estimated in terms of Ki-67 labelling and mitotic indices (KI and MI), demonstrated an overall correlation among AI, KI and MI increases in association with Bcl-2 negativity, indicating a close relation between apoptosis and proliferation. EBV-positive cases showed significantly elevated AI values, independent of Bcl-2 positivity, with no change in KI and MI. These results indicate that EBV in Japanese non-Hodgkin's lymphomas is exclusively of type A with a specific deletion in LMP-1 and that it tends to be present in T cell lymphomas. Moreover, EBV up-regulates apoptosis without any relation to Bcl-2 expression and exerts only minor effects on proliferation.

Low frequency of apoptosis in Epstein-Barr virus-associated gastric carcinoma with lymphoid stroma

In order to understand the character of Epstein-Barr virus (EBV)-associated gastric carcinoma with lymphoid stroma (GCLS), we examined cell proliferation and death in comparison with gastric carcinoma without prominent lymphoid stroma (conventional gastric carcinoma). The EBV-encoded small RNA I (EBER-1) and apoptotic cells were examined by in situ hybridization (ISH) and by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end-labeling (TUNEL), respectively, on formalin-fixed paraffin-embedded surgical specimens from 22 GCLSs and 23 conventional gastric carcinomas. Immunostaining was performed for the detection of Ki-67 antigen (Ki-67), P53 protein (P53) and bcl-2 oncoprotein (BCL-2). The percentages of apoptotic and Ki-67-positive cells were expressed as apoptotic indices (AI) and Ki-67 labeling indices (KI), respectively. EBER-1 was detected in 19 (86%) GCLSs in contrast to none in conventional carcinomas. Mean AI was 1.8 +/- 0.6 in the EBER-1-positive GCLSs and 3.3 +/- 1.7 in the conventional gastric carcinomas, the value being significantly lower in the former (p < 0.01). Mean KI was 40.0 +/- 10.8 in the GCLSs and 48.5 +/- 9.1 in the conventional gastric carcinomas, the value being significantly lower in the former (p < 0.05). P53 expression showed no significant difference between the 2 categories of carcinoma.