The value of EUS in predicting the response of gastric mucosa-associated lymphoid tissue lymphoma to Helicobacter pylori eradication

Effectiveness of Helicobacter pylori eradication in the treatment of early-stage gastric mucosa-associated lymphoid tissue lymphoma: An up-to-date meta-analysis

BACKGROUND

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma (GML) is usually a low-grade B-cell neoplasia strongly associated with Helicobacter pylori (H. pylori)-induced chronic gastritis. Clinical practice guidelines currently recommend H. pylori eradication as the preferred initial treatment for early-stage GML. To determine the practical effect of bacterial eradication as the sole initial therapy for early-stage GML, an updated analysis and review of available evidence is imperative.

AIM

To perform a meta-analysis to assess the rate of complete remission (CR) of H. pylori-positive early-stage GML following bacterial eradication.

METHODS

We performed independent, computer-assisted literature searches using the PubMed/MEDLINE, Embase, and Cochrane Central databases through September 2022. Prospective and retrospective observational studies evaluating the CR of early-stage GML following bacterial eradication in H. pylori-positive patients. The risk of bias was assessed using Joanna Briggs Institute (JBI) Critical Appraisal Tools. The pooled estimate of the complete histopathological remission rate and respective confidence intervals (95%CI) were calculated following the random-effects model. Heterogeneity and inconsistency were assessed using Cochran’s Q test and I² statistic, and heterogeneity was defined as P < 0.01 and I² > 50%, respectively. Subgroup and meta-regression analyses were conducted to explore potential sources of heterogeneity.

RESULTS

The titles and abstracts of 1576 studies were screened; 96 articles were retrieved and selected for full-text reading. Finally, 61 studies were included in the proportional meta-analysis (P-MA). Forty-six were prospective and fifteen were retrospective uncontrolled, single-arm, observational studies. The overall risk of bias was low to moderate in all but a single report, with an average critical appraisal score across all studies of 79.02%. A total of 2936 H. pylori-positive early-stage GML patients, in whom H. pylori was successfully eradicated, were included in the analysis. The pooled CR of H. pylori-positive early-stage GML after bacterial eradication was 75.18% (95%CI: 70.45%-79.91%). P-MA indicated the substantial heterogeneity in CR reported across studies (I² = 92%; P < 0.01). Meta-regression analysis identified statistically significant effect modifiers, including the proportion of patients with t(11;18)(q21;q21)-positive GML and the risk of bias in each study.

CONCLUSION

Comprehensive synthesis of available evidence suggests that H. pylori eradication is effective as the sole initial therapy for early-stage GML. Although the substantial heterogeneity observed across studies limits the interpretation of the pooled overall CR, the present study is a relevant to informing clinical practice.

Mucosa-Associated Lymphoid Tissue Lymphoma Masked as Gastric Varices With Acute Upper Gastrointestinal Bleeding: A Case Report

Extra-nodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) is uncommon and difficult to diagnose due to varied clinical presentations and endoscopic appearances masquerading as other pathology. Rarely, it has been associated with acute upper gastrointestinal (GI) bleeding. We report on a 60-year-old male who presented with an acute upper GI bleed and endoscopic findings suggestive of isolated gastric varices (GV), ultimately determined to be MALT lymphoma. Complete remission was achieved with radiation therapy, with no recurrence at a 12-month follow-up. This case highlights a unique clinical and endoscopic presentation of MALT lymphoma which providers should be aware of. We emphasize the use of endoscopic ultrasound (EUS) evaluation for accurate diagnosis.

Optimal Initial Workup in Patients With Superficial Primary Gastric MALT Lymphoma

BACKGROUND AND AIMS

The prognosis of gastric mucosa-associated lymphoid tissue (MALT) lymphoma is favorable, especially in the absence of lymph node metastasis (LNM). We investigated LNM incidence and location in superficial type gastric MALT lymphoma.

METHODS

We performed a retrospective analysis of 450 patients newly diagnosed with gastric MALT lymphoma with tumor infiltration confined to the mucosa or submucosa as evidenced by endoscopic ultrasonography. LNM incidence and location were evaluated.

RESULTS

Of the 450 patients, most patients (434, 96.4%) were initially LNM negative as confirmed by computed tomography (CT) scanning. Sixteen patients (3.6%) were LNM positive. There was no difference in clinical characteristics between the 2 groups except for the extent of lymphoma involvement and endoscopic findings. Among 41 patients undergoing abdominal/pelvic CT (APCT) only, LNM was detected in 1 (2.4%). There were 8 LNM cases among 238 patients undergoing both APCT and chest CT (3.4%). Among 171 patients undergoing APCT, chest CT, and neck CT, 7 cases of LNM were detected (4.1%). The detection rates for each CT were as follows: abdominal CT, 13/450 (2.9%); chest CT, 6/408 (1.5%); and neck CT, 1/171 (0.6%). Among 6 patients with chest CT-positive findings, 3 showed no evidence of LNM on APCT.

CONCLUSION

LNM was an infrequent finding in gastric MALT lymphoma patients with tumor infiltration confined to the mucosa or submucosa. Besides endoscopy and endoscopic ultrasonography, APCT and chest CT are considered as optimal initial workup modalities in patients with assumed primary superficial gastric MALT lymphoma.

Value of staging information provided by linear-array endoscopic ultrasound for therapeutic response and prognosis prediction in gastric lymphoma

OBJECTIVES

Currently, positron emission tomography/computed tomography (PET/CT)-based Ann Arbor and Lugano staging systems are widely applied for gastric lymphoma, which majorly focused on the extent of systemic invasion, but there is insufficient assessment in extent of gastric wall invasion. Thus, we aimed to assess the value of linear-array EUS in therapeutic response and prognosis prediction, and provide an endoscopic ultrasound (EUS)-based staging system for gastric lymphoma.

METHODS

Between January 2012 and October 2019, 191 patients with histologically confirmed gastric lymphoma were included. We analyzed patients' clinicopathologic data, white-light appearance, EUS staging, tumor extension, and therapeutic regime to identify the predictors for complete remission (CR) and progression-free survival (PFS).

RESULTS

With a median follow-up period of 547 days, 136 patients achieved CR. Multivariate regression analysis identified EUS T stage three CR predictors, including T stage (T2-T4 vs. T1, OR = 0.271, 95% confidence interval (CI) = 0.108-0.683, P = 0.0085) was the independent predictor. The Ki67 index, lesion surface, EUS stage, tumor extension, and regime predicted PFS, but tumor extension was the only independent predictor (local vs. system, OR = 6.005, 95%CI = 2.365-15.236, P < 0.001). The concordance index (C-index) was higher for CR rate in the EUS-based staging [0.673; 95% CI = 0.628-0.718] than Lugano staging [0.663; 95% CI 0.616-0.710], and for PFS in the EUS-based staging [0.694; 95% CI 0.586-0.802] than Lugano staging [0.684; 95% CI 0.564-0.804].

CONCLUSIONS

An EUS-based staging system is suitable for CR and PFS prediction in gastric lymphoma, with highly informative assessment in extent of gastric wall invasion.

Epidemiology, Diagnosis, Staging and Multimodal Therapy of Esophageal and Gastric Tumors

Gastric and esophageal tumors are diverse neoplasms that involve mucosal and submucosal tissue layers and include squamous cell carcinomas, adenocarcinomas, spindle cell neoplasms, neuroendocrine tumors, marginal B cell lymphomas, along with less common tumors. The worldwide burden of esophageal and gastric malignancies is significant, with esophageal and gastric cancer representing the ninth and fifth most common cancers, respectively. The approach to diagnosis and staging of these lesions is multimodal and includes a combination of gastrointestinal endoscopy, endoscopic ultrasound, and cross-sectional imaging. Likewise, therapy is multidisciplinary and combines therapeutic endoscopy, surgery, radiotherapy, and systemic chemotherapeutic tools. Future directions for diagnosis of esophageal and gastric malignancies are evolving rapidly and will involve advances in endoscopic and endosonographic techniques including tethered capsules, optical coherence tomography, along with targeted cytologic and serological analyses.

Analysis of the response time to involved-field radiotherapy in primary gastrointestinal low-grade B-cell lymphoma

BACKGROUND

Early-stage primary gastrointestinal (GI) low-grade B-cell lymphoma shows good therapeutic response to primary radiotherapy. However, there is no clear guideline for the evaluation of response to radiation therapy currently. The aim of this study was to analyze the relationship between the best response time and the clinical course after radiotherapy.

METHODS

Patients who underwent radiotherapy for treatment of primary GI low-grade B-cell lymphoma from September 2007 to December 2018 at Seoul St. Mary's Hospital were included. Early responders were defined by best response within 6 months after radiotherapy, and delayed responders after 6 months. Clinical and pathological factors associated with delayed response and survival analyses were performed to investigate the recurrence and survival during follow-up.

RESULTS

A total of 43 patients were evaluated and the number of gastric mucosa-associated lymphoid tissue and duodenal follicular lymphoma was 36 and 7, respectively. All of 43 patients showed complete remission to radiotherapy and the best response time after radiotherapy was a median of 3 months. There were 8 delayed responders with a median duration of 8.9 months. Early and delayed responders were characterized by a significant difference in depth of invasion beyond the mucosal layer.

CONCLUSIONS

Delayed responders did not show differences in oncological outcomes compared with early responders. They were allowed to watch and wait for an additional 6 to 12 months without further treatment.

Endoscopic features aiding the diagnosis of gastric mucosa-associated lymphoid tissue lymphoma

The incidence of gastric mucosa-associated lymphoid tissue (MALT) lymphoma is increasing worldwide, but the diagnosis is difficult. Most patients are asymptomatic or complain of nonspecific gastrointestinal symptoms. As the endoscopic features of gastric MALT lymphoma are variable and nonspecific, the possibility of this condition may be overlooked during esophagogastroduodenoscopy, and it remain undiagnosed. Therefore, this condition needs to be considered when an abnormal mucosa is observed during this procedure. Biopsy performed during endoscopy is the primary diagnostic test, but false negative results are possible; large numbers of samples should be collected from both normal and abnormal mucosae. Endoscopic ultrasonography is useful to assess the depth of invasion and to predict the treatment response. After treatment, follow-up tests are required every 3 months until complete remission is achieved, and annually thereafter. Early diagnosis of gastric MALT lymphoma is difficult, and its diagnosis and follow-up require wide experience and competent endoscopic technique.

Diagnostic classification of endosonography for differentiating colorectal ulcerative diseases: A new statistical method

AIM

To establish a classification method for differential diagnosis of colorectal ulcerative diseases, especially Crohn’s disease (CD), primary intestinal lymphoma (PIL) and intestinal tuberculosis (ITB).

METHODS

We searched the in-patient medical record database for confirmed cases of CD, PIL and ITB from 2008 to 2015 at our center, collected data on endoscopic ultrasound (EUS) from randomly-chosen patients who formed the training set, conducted univariate logistic regression analysis to summarize EUS features of CD, PIL and ITB, and created a diagnostic classification method. All cases found to have colorectal ulcers using EUS were obtained from the endoscopy database and formed the test set. We then removed the cases which were easily diagnosed, and the remaining cases formed the perplexing test set. We re-diagnosed the cases in the three sets using the classification method, determined EUS diagnostic accuracies, and adjusted the classification accordingly. Finally, the re-diagnosing and accuracy-calculating steps were repeated.

RESULTS

In total, 272 CD, 60 PIL and 39 ITB cases were diagnosed from 2008 to 2015 based on the in-patient database, and 200 CD, 30 PIL and 20 ITB cases were randomly chosen to form the training set. The EUS features were summarized as follows: CD: Thickened submucosa with a slightly high echo level and visible layer; PIL: Absent layer and diffuse hypoechoic mass; and ITB: Thickened mucosa with a high or slightly high echo level and visible layer. The test set consisted of 77 CD, 30 PIL, 23 ITB and 140 cases of other diseases obtained from the endoscopy database. Seventy-four cases were excluded to form the perplexing test set. After adjustment of the classification, EUS diagnostic accuracies for CD, PIL and ITB were 83.6% (209/250), 97.2% (243/250) and 85.6% (214/250) in the training set, were 89.3% (241/270), 97.8% (264/270) and 84.1% (227/270) in the test set, and were 86.7% (170/196), 98.0% (192/196) and 85.2% (167/196) in the perplexing set, respectively.

CONCLUSION

The EUS features of CD, PIL and ITB are different. The diagnostic classification method is reliable in the differential diagnosis of colorectal ulcerative diseases.

18F-Fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography in mucosa-associated lymphoid tissue lymphoma: variation in 18F-FDG avidity according to site involvement

The purpose of this study was to determine the 18F-FDG avidity of MALT lymphoma and the additional utility of 18F-FDG PET/CT in MALT lymphoma staging. Pretreatment 18F-FDG PET/CT scans of 222 patients with 227 MALT lymphoma lesions were retrospectively analyzed. 18F-FDG avidity of lesions was noted in 28%. The proportion was lower for gastric MALT lymphomas than for non-gastric lesions (9% vs. 60%, p<0.0001) and higher for mass-forming lesions than for superficial lesions (82% vs. 2%, p<0.0001). 18F-FDG PET/CT showed the presence of additional lesions in 23 patients: four of six true-positive lesions had 18F-FDG avid primary lesions, and 15 of 17 false-positive lesions had 18F-FDG-non avid lesions. 18F-FDG avidity differed according to the location and gross morphologic characteristics of the MALT lymphoma. Most gastric MALT lymphomas were superficial and had low 18F-FDG avidity. For staging, 18F-FDG PET/CT can be helpful mainly for 18F-FDG avid primary MALT lymphomas.

Endoscopic features of gastro-intestinal lymphomas: From diagnosis to follow-up

Many progresses have been done in the management of gastrointestinal (GI) lymphomas during last decades, especially after the discovery of Helicobacter pylori-dependent lymphoma development. The stepwise implementation of new endoscopic techniques, by means of echoendoscopy or double-balloon enteroscopy, enabled us to more precisely describe the endoscopic features of GI lymphomas with substantial contribution in patient management and in tailoring the treatment strategy with organ preserving approaches. In this review, we describe the recent progresses in GI lymphoma management from disease diagnosis to follow-up with a specific focus on the endoscopic presentation according to the involved site and the lymphoma subtype. Additionally, new or emerging endoscopic technologies that have an impact on the management of gastrointestinal lymphomas are reported. We here discuss the two most common subtypes of GI lymphomas: the mucosa-associated lymphoid tissue and the diffuse large B cell lymphoma. A general outline on the state-of-the-art of the disease and on the role of endoscopy in both diagnosis and follow-up will be performed.

The role of endoscopic ultrasound in the diagnosis and therapy of gastrointestinal disorders

Endoscopic ultrasound is one of those diagnostic methods in gastrointestinal endoscopy which has developed rapidly in the last decade and has became exceedingly available to visualize the walls of the internal organs in details corresponding to histological layers, or analyze the adjacent structures. Fine needles and other endoscopic accessories can be introduced into the neighbouring tissues under the guidance of endoscopic ultrasound, and diagnostic and minimally invasive therapeutic interventions can be performed. The endoscopic ultrasound became more widely available in Hungary in the recent years. This review focuses on the indications, benefits and complications of diagnostic and therapeutic endoscopic ultrasound. We dedicate this article for gastroenterologists, surgeons, internists, pulmonologists, specialists in oncology and radiology. This recommendation was based on the consensus of the Board members of the Endoscopic Ultrasound Section of the Hungarian Gastroenterological Society. Orv. Hetil., 2014, 155(14), 526–540.

Endocytoscopic findings of lymphomas of the stomach

BACKGROUND

The gastric lesions of various lymphomas were observed at the cellular level using endocytoscopy.

METHODS

Endocytoscopy and magnifying endoscopy with narrow band imaging (NBI) were performed in 17 patients with lymphomas of the stomach. The lesions consisted of 7 with low-grade mucosa-associated lymphoid tissue (MALT), 5 with gastric involvement by adult T-cell leukemia/lymphoma (ATLL), 4 with diffuse large B-cell lymphoma (DLBCL), and 1 with peripheral T-cell lymphoma.

RESULTS

On conventional endoscopy, 9 were classified as having superficial spreading type, 7 were mass-forming type, and 1 was diffuse infiltrating type. Anti-H. pylori treatment was given in the 7 MALT lymphoma cases. NBI magnification endoscopy invariably showed dilatation or ballooning and destruction of gastric pits and elongation and distortion in microvessels. Endocytoscopy showed mucosal aggregation of interstitial cellular elements in almost all gastric lymphoma cases. The nuclear diversity in size and configuration was exclusively seen in gastric lymphomas other than MALT lymphoma, whereas the nuclei of MALT lymphoma cells were regular and small to moderate in size. Inter-glandular infiltration by lymphomatous cell elements was frequently observed in MALT lymphoma and DLBCL, but it was uncommon in peripheral gastric T-cell malignancies. Endocytoscopy could identify the disease-specific histology, the lymphoepithelial origin, as inter-glandular infiltration of cellular components in MALT lymphoma and the possibly related DLBCL cases. Complete regression (CR) was observed in 2 of the 7 MALT lymphoma patients. In the 2 patients with CR who underwent repeat endocytoscopy, the ultra-high magnification abnormalities returned to normal, while they were unchanged in those without tumor regression.

CONCLUSIONS

On endocytoscopy, intra-glandular aggregation of cellular components was invariably identified in lymphomas of the stomach. Nuclear regularity in size and configuration may indicate the cytological grade, differentiating the indolent low-grade from aggressive lymphoproliferative diseases. The inter-glandular infiltration seen on endocytoscopy can indicate the lymphoepithelial lesions seen in MALT lymphoma and related DLBCL. Endocytoscopy would be applicable for virtual histopathological diagnosis of different lymphoproliferative disorders and their clinical assessment during ongoing endoscopy.

Duodenal mucosa-associated lymphoid tissue lymphomas: two cases and the evaluation of endoscopic ultrasonography

Mucosa-associated lymphoid tissue lymphoma mainly arises in the stomach, with fewer than 30% arising in the small intestine. We describe here two cases of primary duodenal mucosa-associated lymphoid tissue lymphoma which were evaluated by endoscopic ultrasonography. A 52-year-old man underwent endoscopy due to abdominal pain, which demonstrated a depressed lesion on duodenal bulb. Endoscopic ultrasonographic finding was hypoechoic lesion invading the submucosa. The other case was a previously healthy 51-year-old man. Endoscopy showed a whitish granular lesion on duodenum third portion. Endoscopic ultrasonography image was similar to the first case, whereas abdominal computed tomography revealed enlargement of multiple lymph nodes. The first case was treated with eradication of Helicobacter pylori, after which the mucosal change and endoscopic ultrasound finding were normalized in 7 months. The second case was treated with cyclophosphamide, vincristine, prednisolone, and rituximab every 3 weeks. After 6 courses of chemotherapy, the patient achieved complete remission.

Role of F-FDG PET Scans in Patients with Helicobacter pylori-Infected Gastric Low-Grade MALT Lymphoma

Background/Aims

Endoscopic ultrasound (EUS) plays a crucial role in the assessment and treatment of low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma; however, interobserver variation, inadequate accuracy in judging the depth of tumor invasion, and histological heterogeneity of the tumor can limit its role. Thus, we have assessed the role of ¹⁸F-FDG PET scans in the management of Helicobacter pylori-infected gastric MALT lymphoma.

Methods

Eighteen patients with H. pylori-infected low-grade gastric MALT lymphoma underwent an ¹⁸F-FDG PET scan prior to receiving H. pylori eradication therapy. We analyzed these patients' clinicopathologic data and measured the baseline and change in the metabolic activity of the tumor using standardized uptake values (SUVs).

Results

Two patients failed to achieve complete remission of the low-grade gastric MALT lymphoma after successful H. pylori eradication. The baseline SUVs were significantly higher in these patients compared to successfully treated patients, 13.35±0.07 vs 2.98±0.93, respectively (n=2 vs n=16, p<0.001). The reduction in the SUV was significantly greater in the complete remission patients compared to treatment failure patients (p=0.018).

Conclusions

A high SUV at baseline ¹⁸F-FDG PET and a lower reduction in the SUV within 3 months after eradication therapy are associated with treatment failure in H. pylori-positive low-grade gastric MALT lymphoma patients undergoing eradication treatment.

The usefulness of endoscopic ultrasound in the differential diagnosis between benign and malignant gastric ulcer

OBJECTIVE

Gastric cancer can present as an exophytic lesion, diffuse infiltration of the gastric mucosa or even as a gastric ulcer, which can mimic a benign gastric ulcer. The purpose of this study was to evaluate the value of endoscopic ultrasound (EUS) in the differential diagnosis between benign and malignant gastric ulcer.

MATERIAL AND METHODS

176 patients with gastric ulcer were divided into two groups on the basis of the cause of ulcer. Benign gastric ulcer group consisted of 102 patients and malignant gastric ulcer group consisted of 74 patients. All patients were examined by radial scanning echoendoscope (Olympus GF-UM 2000).

RESULTS

For diagnosis of malignant gastric ulcer, the sensitivity of EUS is 83.8%, the specificity is 62.7% and the accuracy is 71.6%.

CONCLUSIONS

The results demonstrate that EUS is a useful examination in differential diagnosis between benign and malignant gastric ulcer. However, it also has certain limitation which may be solved with more newer EUS applications and development.

Primary low-grade and high-grade gastric MALT-lymphoma presentation

GOAL

To assess the clinical and endoscopic presentation of primary gastric lymphoma.

BACKGROUND

Remission rate and long-term survival in patients with gastric lymphoma mainly depend on disease stage at diagnosis. Series reporting clinical and endoscopic presentation of gastric lymphoma are generally small and heterogeneous.

STUDY

Systematic review with pooled-data analysis assessing clinical and endoscopic presentation of primary gastric lymphoma.

RESULTS

Data regarding 2000 patients were collected. Overall, males were slightly more prevalent, alarm symptoms were absent in near half of the patients, lymphoma was diagnosed in a stage >I in one-third of the patients, and Helicobacter pylori infection was present in 88.8% of considered patients. At endoscopy, the ulcerative type was the most frequent presentation, although low-grade lymphoma was diagnosed on normal/hyperemic gastric mucosa in 9% of cases. Patients with high-grade lymphoma presented alarm symptoms (anemia and/or melena and/or hemorrhage, persistent vomiting, weight loss), an exophytic or ulcerative lesion, a stage III-IV, and a H. pylori negative status more frequently than low-grade lymphoma cases.

CONCLUSIONS

Our pooled-data analysis showed that gastric lymphoma is still disappointingly diagnosed in an advanced stage in a large number of patients. This is probably due to presence of nonspecific symptoms at initial clinical presentation and/or a normal appearing mucosa at endoscopic observation in the early stages.

Effects of Helicobacter pylori eradication on early stage gastric mucosa-associated lymphoid tissue lymphoma

BACKGROUND & AIMS

Different remission rates of gastric low-grade, B-cell, mucosa-associated lymphoid tissue (MALT) lymphoma have been reported after Helicobacter pylori eradication. We assessed the long-term remission and relapse rates of early stage MALT lymphoma in patients treated only by H pylori eradication and identified factors that might predict outcome.

METHODS

This systematic review analyzed data from 32 studies, including 1408 patients.

RESULTS

The MALT lymphoma remission rate was 77.5% (95% confidence interval, 75.3-79.7), and was significantly higher in patients with stage I than stage II(1) lymphoma (78.4% vs 55.6%; P = .0003) and in Asian than in Western groups (84.1% vs 73.8%; P = .0001). Neoplasia confined to the submucosa regressed more frequently than that with deeper invasion (82.2% vs 54.5%; P = .0001); patients with lymphoma localized to the distal stomach experienced regression more frequently than those with lymphoma of the proximal stomach (91.8% vs 75.7%; P = .0037). The remission rate was higher among patients without the API2-MALT1 translocation than in those with this translocation (78% vs 22.2%; P = .0001). In an analysis of data from 994 patients, 7.2% experienced lymphoma relapse during 3253 patient-years of follow-up evaluation, with a yearly recurrence rate of 2.2%. Infection and lymphoma were cured by additional eradication therapy in all patients with H pylori recurrence (16.7%). Five (0.05%) of the patients initially cured of lymphoma developed high-grade lymphoma within 6 to 25 months of therapy.

CONCLUSIONS

H pylori eradication is effective in treating approximately 75% of patients with early stage gastric lymphoma. Long-term follow-up evaluation of these patients is needed to detect early lymphoma relapse or progression.

Staging role of EUS

Type of lymphoma and stage of disease are the two decisive prognostic factors and therapeutic determinants. For the locoregional staging, i.e. assessment of the gastric wall infiltration and perigastric lymphonodular involvement, endoscopic ultrasound (EUS) is highly useful. EUS has, therefore, to be integrated into the standard staging procedure of gastric lymphoma, although its impact on initial treatment decisions might be limited in the individual case. A benefit from the use of miniechoendoscopes, EUS elastography and EUS-guided biopsies has not yet been proven in gastric lymphoma. EUS also confers an important prognostic value regarding treatment responses to Helicobacter pylori eradication. On the contrary, EUS cannot be recommended as a regular part of follow-up investigations considering its limited value in predicting the response of the lymphoma to radiation or chemotherapy.

Gastric oncology: an update

PURPOSE OF REVIEW

As the field of endoscopy progresses, new tools and techniques continue to be developed for gastroenterology in general and gastrointestinal oncology in particular. Some of these include enhancements in diagnostic optics such as chromoendoscopy, magnification endoscopy, and confocal laser endomicroscopy. Others include advanced therapeutics such as endoscopic mucosal resection and endoscopic submucosal dissection. In this review, we will update the reader on these latest of technologies, their benefits and risks, as well as their role in evaluating, staging, and treating gastric neoplasms, especially gastric adenocarcinoma, gastrointestinal stromal tumors, and primary gastric lymphoma.

RECENT FINDINGS

Noteworthy studies in this review indicate that in properly selected patients with gastric adenocarcinoma, endoscopic submucosal dissection is a viable alternative to gastric resection with 100% 5-year survival rates; in patients with metastatic gastrointestinal stromal tumors, imatinib can provide effective treatment with reasonable outcome; and in patients with low grade mucosa-associated lymphoid tissue lymphoma, eradication therapy with antibiotics is curative with a very low recurrence rate.

SUMMARY

The advances discussed in this review have significantly improved the care we can offer our patients in gastric oncology. With continued advancement in the field, it will be crucial to continue to study outcomes and safety of these techniques and to develop structured training for those looking to perform these procedures.

The impact of EUS in primary gastric lymphoma

Gastric lymphoma is the most frequent site of gastrointestinal lymphoma and is accessible for endosonographic evaluation. Most primary gastric lymphomas are classified as mucosa-associated lymphoid tissue (MALT)-type lymphomas that develop in the course of chronic Helicobacter pylori infection. Endoscopic ultrasonography (EUS) is regarded to be the most accurate method for the local staging of gastric lymphoma, although scientific evidence is limited. In stage uEI1 low-grade lymphoma, EUS is able to predict a high chance for cure by H. pylori eradication. The significance of EUS elastography or EUS-guided fine-needle aspiration biopsy to diagnose nodal involvement has not been investigated in prospective series yet. Since high-grade lymphoma is always treated as a systemic disease, the impact of endosonographic staging is lower than in low-grade lymphoma. After treatment of primary gastric lymphoma, EUS produces conflicting results that are not as accurate as endoscopy with biopsy. Therefore, EUS is not mandatory during follow-up.

Eradication therapy for Helicobacter pylori in patients with gastric MALT lymphoma: a pooled data analysis

OBJECTIVES

Helicobacter pylori eradication is recognized as the initial therapy for gastric low-grade, B-cell, mucosa-associated lymphoid tissue (MALT) lymphoma. This study assesses (i) the H. pylori eradication rates for various first- and second-line and rescue therapies and (ii) the associated reinfection rates in patients.

METHODS

Pooled data analysis of systematic review of the literature was performed in this study.

RESULTS

Data from 34 studies with 1,271 treated patients were used. After first-line therapy, the infection was cured in 91% (95% confidence interval (CI)=89.4-92.5) of cases, the eradication rate being higher after dual therapy compared with the 7- or 14-day triple therapies (P=0.0525). After second-line therapy, the eradication rate was 80.8% (95% CI=82.7-95.1), being higher after triple rather than quadruple therapy. Further therapies (from three to five attempts) cured the infection in 75% of patients. H. pylori infection was ultimately cured in 1,250 patients, resulting in eradication rates of 98.3% (95% CI=97.6-99) and 99.8% (95% CI=99.6-100) at intention-to-treat and per-protocol analysis levels, respectively. Bacterial reinfection occurred in 18 (2.7%; 95% CI=1.4-3.9) of 676 patients who were followed-up (0.7% yearly). Overall, gastric lymphoma remission was achieved in 973 (77.8%) of 1,250 patients successfully cured of H. pylori infection.

CONCLUSIONS

This was the first comprehensive ( approximately 1,300 patients) analysis of the therapeutic management of H. pylori in gastric lymphoma patients. Data suggest that this infection is easily managed in these patients, being cured in nearly all cases.

Treatment of low-grade gastric MALT-lymphoma unresponsive to Helicobacter pylori therapy: a pooled-data analysis

The most favourable therapeutic strategy for gastric MALT-lymphoma not responding to Helicobacter pylori eradication still remains unclear, neither official guidelines nor randomised studies being available. We therefore performed a systematic review of the literature to evaluate the efficacy of different therapeutic approaches in these patients. Data regarding 315 patients were valuable, and lymphoma remission following the first therapeutic attempt was achieved in 90.1% cases. The most used therapy was radiotherapy (112 patients), followed by surgery (80 patients) and chemotherapy (68 patients), whilst a combination therapy was less frequent. Radiotherapy achieved a higher remission rate as compared to chemotherapy (97.3 vs. 85.3%; P = 0.007), being similar to surgery (97.3 vs. 92.5%; P = 0.2). No difference emerged when comparing lymphoma remission rate achieved by a single therapy with that of combined treatments (89.6 vs. 96.4%; P = 0.6). This is the first pooled-data analysis assessing the efficacy of different oncologic therapeutic approaches to treat gastric MALT-lymphoma unresponsive to H. pylori eradication. Radiotherapy seems to be the most suitable treatment in these patients.

Endoscopic diagnosis and staging of mucosa-associated lymphoid tissue lymphoma

PURPOSE OF REVIEW

The role of endoscopy, including endoscopic ultrasound, in the diagnosis and management of mucosa-associated lymphoid tissue lymphomas of the stomach has evolved steadily in the last two decades. The present review summarizes recent findings and puts them in context with studies on the diagnosis and management of mucosa-associated lymphoid tissue lymphoma published earlier.

RECENT FINDINGS

Several recent studies have emphasized the crucial role of endoscopic ultrasound in treatment planning in patients with gastric mucosa-associated lymphoid tissue lymphoma. This is important as early-stage gastric mucosa-associated lymphoid tissue lymphomas can be managed just by the eradication of Helicobacter pylori by appropriate antibiotic regimens. However, the more advanced lesions are treated with much more invasive treatment regimens involving radical gastrectomy, chemotherapy or radiation, or all.

SUMMARY

Endoscopic ultrasound staging is highly accurate in predicting response to Helicobacter pylori eradication in patients with gastric mucosa-associated lymphoid tissue lymphoma. Normalization of gastric wall thickness and architecture can be used to monitor tumor regression following treatment. Endoscopic ultrasound findings can also be used to identify treatment failures and relapses and can help identify patients who need more aggressive therapy.

Advances on the treatment of gastric mucosa-associated lymphoid tissue lymphoma

Gastric mucosa-associated lymphoid tissue (MALT) lymphomas are rare in the gut, and its occurrence rate was 1% to 5% of the malignant tumors. In histological type, most of them are non-Hodgin's lymphomas, while Hodgin's lymphomas are seldom seen. There have been a lot of controversies on the optimal treatments of gastric MALT lymphomas for a long time. Surgery was traditionally considered as the most important approach to cure the disease. However, anti-H. pylori therapy has been regarded as an alternative method since H. pylori infection was found to be relevant with the pathogenesis of gastric MALT lymphomas. In this article, we reviewed the current status and recent advances on the treatment of this disease.