Lymphoid proliferations and lymphomas associated with gastric metaplasia, dysplasia, and carcinoma

Estimating the Global Burden of Epstein-Barr Virus-Associated Gastric Cancer: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Evidence suggests that a fraction of new gastric cancer cases may be etiologically associated with Epstein-Barr virus (EBV), a known carcinogenic agent. We aimed to systematically explore the proportion of EBV-positive gastric cancer.

METHODS

We did a systematic review (PROSPERO CRD42020164473) from January 1990 to August 2021. For each country and geographical region with available data, pooled prevalence and corresponding 95% confidence intervals (CIs) of EBV in gastric tumors were calculated for 3 subtypes of gastric adenocarcinoma (conventional adenocarcinoma, lymphoepithelioma-like gastric carcinoma, and remnant/stump carcinoma). For conventional adenocarcinoma, prevalence ratios (PRs) were presented for sex, Lauren's classification, gastric cancer stage, and anatomical location of the stomach.

RESULTS

In 220 eligible studies including over 68,000 cases of conventional gastric adenocarcinoma, EBV prevalence in tumor cells was 7.5% (95% CI, 6.9%-8.1%) and was higher in men compared with women (PR, 2.1; 95% CI, 1.9-2.4), in diffuse type compared with intestinal type (PR, 1.3; 95% CI, 1.1-1.5), and in the proximal region compared with the distal region (PR, 2.5; 95% CI, 2.0-3.1). There was no difference in EBV prevalence by gastric cancer stage. EBV prevalence was 75.9% (95% CI, 62.8%-85.5%) among lymphoepithelioma-like gastric carcinoma and 26.3% (95% CI, 22.2%-32.0%) among remnant or stump carcinoma.

CONCLUSIONS

Assuming a causal association between EBV and gastric cancer, our findings, when applied to the GLOBOCAN 2020 gastric cancer incidence, suggest that primary prevention such as the development of an effective EBV vaccine might prevent 81,000 EBV-associated gastric cancer cases worldwide annually.

Inflammatory Stroma of Lymphoepithelioma-like Carcinoma of the Cervix: Immunohistochemical Study of 3 Cases and Review of the Literature

The aim of this study was to characterize the inflammatory infiltrate of the lymphoepithelioma-like carcinoma, a variant of squamous cell carcinoma clinically associated with a good prognosis. Immunohistochemistry was used to characterize 3 cases of lymphoepithelioma-like carcinoma in the uterine cervix, diagnosed over a period of 3 yr. The patients were between 30 and 50 yr old. Their cervical smears had shown atypical squamous cells of unknown significance or high-grade squamous intraepithelial lesions, and the initial cervical biopsy showed high-grade cervical intraepithelial neoplasia (CIN3) or squamous cell carcinoma. All patients underwent a Wertheim operation, 2 of which were preceded by a cervicectomy. Microscopically, all tumors were characterized by poorly defined sheets of undifferentiated squamous cells with a syncytial pattern and a dense background of infiltrating lymphocytes. Immunohistochemical analysis revealed that the lymphocytes were predominantly CD3 and CD8 T cells. The tumor lobules contained isolated CD8 T cells, whereas CD4 T cells and CD20 B cells surrounded the tumor lobules. CD56 NK cells and CD79 B cells were scattered in the tumor tissue. An in situ hybridization staining for Epstein-Barr encoding region was negative but all cases were immunohistochemically positive for P16. Follow-up varied between 2 mo and 2.7 yr. All 3 patients were disease free. Lymphoepithelioma-like carcinoma of the uterine cervix is a variant of squamous cell carcinoma, known for its better prognosis. The good prognosis of this tumor is potentially explained by the high levels of infiltrating CD8 T cells.

Increased risk for metachronous gastric adenocarcinoma following gastric MALT lymphoma-A US population-based study

BACKGROUND

Gastric mucosa-associated lymphoid tissue lymphoma (gMALT) and gastric adenocarcinoma (GC) are long-term complications of chronic Helicobacter pylori (HP) gastritis. Treatment of HP infection induces remission in most patients with gMALT. Endoscopic follow-up is not currently endorsed after complete remission. However, the risk of GC in these patients is unclear.

OBJECTIVE

The objective of this study is to estimate GC risk in gMALT patients.

METHODS

The National Cancer Institute Surveillance, Epidemiology and End Results 13 (SEER) database-Nov 2014 Sub (1992-2012) was used to identify adult patients diagnosed with gMALT between 1992 and 2012. The standardized incidence ratio of second primary GC after a latency period of 12 months was calculated and compared to a reference SEER cohort of identical age, sex and time period. The risk of GC in these patients was also stratified by latency period (five years) and age.

RESULTS

We identified 2195 cases of gMALT lymphoma, and 20 (0.91%) of them subsequently developed GC with a relative risk (RR) of 4.32 (95% CI 2.64-6.67) compared to the American population. The median latency time was five years and the risk was maintained afterward (RR 4.92, 95% CI 2.45-8.79). When stratified by age group the risk was highest for the 45-64 group (RR 14.04, 95% CI 5.64-28.93).

CONCLUSION

gMALT lymphoma is associated with an increased risk of metachronous gastric adenocarcinoma. The risk is still present after more than five years of follow-up. Further studies may clarify the most adequate follow-up strategy.

Sustained epithelial proliferation in a functionally irreversible fundic mucosa after Helicobacter pylori eradication

BACKGROUND

We recently reported the expansion of the acid-secreting mucosa following Helicobacter pylori eradication with Congo red chromoendoscopy for a short-term follow-up of up to 7 months. We aimed to extend the observation period and to clarify the characteristic features of acid-secreting and non-acid-secreting mucosa.

METHODS

In 24 H. pylori-positive patients with fundic atrophy, Congo red chromoendoscopy was performed prior to, 1 month, 7 months, and finally more than 2 years after the eradication. The areas of the acid-secreting mucosa were evaluated semiquantitatively. Two gastric biopsy specimens were taken from the acid-secreting and non-acid-secreting areas at the final chromoendoscopy and were subjected to histologic evaluation and immunohistochemistry for Ki-67 as a proliferation index.

RESULTS

After a gradual increase in acid-secreting areas for up to 7 months after eradication, they further increased in 79% subjects between 7 months and the final observation at a mean follow-up of 62 months. However, there still existed non-acid-secreting mucosa in the fundic area in all subjects, indicating that the expansion of acid-secreting mucosa remained partial. Compared with the neighboring acid-secreting area, the non-acid-secreting area was characterized histologically by higher degrees of residual inflammation, mucosal atrophy, and intestinal metaplasia, and by sustained hyperproliferation as well.

CONCLUSIONS

Functionally irreversible (non-acid-secreting) gastric mucosa after eradication was associated with extensive intestinal metaplasia and sustained hyperproliferation, suggesting that such mucosa still possesses malignant potential. Congo red chromoendoscopy may be useful for estimating the risk of subsequent development of gastric cancer following successful H. pylori eradication by determining the distribution of functionally irreversible mucosa.

Clinicopathological and molecular characteristics of Epstein-Barr virus-associated gastric carcinoma: a meta-analysis

There is conflicting data regarding the clinicopathological significance of the risk factors associated with Epstein-Barr virus (EBV)-associated gastric carcinoma (EBVaGC). To address this controversy, we performed a meta-analysis for the clinicopathological and molecular characteristics of EBVaGC. The relevant published studies were reviewed according to the defined selection criteria. The effect sizes of the outcome parameters were estimated by an odds ratio or a weighted mean difference. This meta-analysis included 48 studies that encompassed a total of 9738 patients. The frequency of EBVaGC was 8.8%, and EBVaGC was significantly associated with ethnicity. It was more predominant in men and in younger individuals. Interestingly, EBVaGC was more prevalent in Caucasian and Hispanic patients than in Asian ones. EBVaGC developed most often in the cardia and body, and it generally showed the diffuse histological type. EBV was highly prevalent in the patients with lymphoepithelial carcinoma. EBVaGC was closely associated with remnant cancer and a CpG island methylator-high status, but not with Helicobacter pylori infection, a TP53 expression, and p53 mutation. In addition, EBVaGC was not significantly associated with the depth of invasion, lymph node metastasis, or the clinical stage. The clinicopathological and molecular characteristics of EBVaGC are quite different from those of conventional gastric adenocarcinoma. However, further study is needed to determine the effect of EBV on the survival of EBVaGC patients.

Helicobacter pylori as a promoter of accelerated regeneration, pathological differentiation and transformation of normal gastric mucosa into cancerous type

The aim of the study was to ascertain presence of Helicobacter pylori in gastric carcinoma as a responsible promoter of inflammatory-regenerative changes, which lead to pathological differentiation and transformation of normal epithelial cells into intestinal type and, in progression, cause epithelial dysplasia that develops into early gastric carcinoma. The paper presents prospective study that includes clinical, pathohistological and microbiological aspects of carcinogenesis initiation in gastric mucosa. The subjects are patients treated at Gastroenterohepatology Clinic divided into two groups. One group included 50 patients with gastric carcinoma while the control group included 50 patients with chronic atrophic H. pylori positive gastritis. All the patients were subjected to endoscopy as well as biopsy targeted at antrum, lesser curvature and corpus and at the region 1-2 cm removed from tumor lesion. We used HUT test to verify H. pylori presence in biopsy samples. We analyzed the samples for presence, frequency and severity of inflammatory-regenerative, metaplastic and dysplastic changes in gastric mucosa and evaluated their meaning for the prognosis. Our study confirmed Helicobaster pylori responsibility for inflammatory events in gastric mucosa in patients with gastric carcinoma. Slight and mild epithelial dysplasia with chronic atrophic gastritis grade I and II coupled with intestinal metaplasia may be considered an indicator for early detection of carcinoma. Such patients represent risk group for gastric carcinoma development.

Synchronous and metachronous occurrence of gastric adenocarcinoma and gastric lymphoma: A review of the literature

The occurrence of both primary gastric lymphoma and gastric adenocarcinoma in the same patient is a rare entity. The possible causative factors of synchronous or metachronous occurrence of both malignancies and varieties in the treatment modalities are reviewed according to published cases in English language medical literature.

Gastric adenocarcinoma in a patient re-infected with H. pylori after regression of MALT lymphoma with successful anti-H. pylori therapy and gastric resection: a case report

BACKGROUND

Helicobacter pylori (H. pylori) has been etiologically linked with primary gastric lymphoma (PGL) and gastric carcinoma (GC). There are a few reports of occurrence of both diseases in the same patients with H. pylori infection.

CASE PRESENTATION

We report a patient with PGL in whom the tumor regressed after surgical resection combined with eradication of H. pylori infection. However, he developed GC on follow up; this was temporally associated with recrudescence/re-infection of H. pylori. This is perhaps first report of such occurrence.

CONCLUSIONS

Possible cause and effect relationship between H. pylori infection and both PGL and GC is discussed. This case also documents a unique problem in management of PGL in tropical countries where re-infection with H. pylori is supposed to be high.