Primary gastric B-cell lymphoma: results of a prospective multicenter study. The German-Austrian Gastrointestinal Lymphoma Study Group

Clinical, histological and molecular follow-up of 60 patients with gastric marginal zone lymphoma of mucosa-associated lymphoid tissue

The persistence of gastric lymphoma after Helicobacter pylori eradication may be difficult to evidence on endoscopic and histological examination. The aims of the study were to evaluate the detection of monoclonal immunoglobulin H (IgH) gene rearrangement in endoscopically infiltrated and normal mucosa at diagnosis and during follow-up in order to determine its clinical and prognostic impact. We studied 60 gastric marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT), and IgH monoclonality was detected at diagnosis in 52 patients (87%). The endoscopically normal mucosa contained clonal lymphomatous cells in 69% of cases before remission. A complete histological remission (HR) was observed in 28 patients (47%). Among them, 23 were followed for molecular remission (MR). The median delay was 10 months to achieve HR and 18 months to achieve MR. Interestingly, patients with HR but not MR had a longer delay to achieve HR (21 months) (P=0.0006) and a more frequent clonal normal mucosa at diagnosis (88%) than patients with both HR and MR (10 months and 39%, respectively). The presence of monoclonal B cells at both infiltrated and normal sites may therefore identify patients with a longer delay to achieve complete response, suggesting that molecular dissemination may require therapeutic intensification.

Conservative management of gastric lymphoma: the treatment option of choice

The study was initiated to assess the safety and effectiveness of primary chemotherapy (CHT) followed by radiotherapy (RT) compared to surgery prior to CHT and/or RT in the management of localized gastric lymphoma. Ninety-two patients treated between 1985 and 2000 were included in a retrospective analysis. Sixty patients received primary CHT followed by extended field or involved field RT. Thirty-two patients had undergone primary surgery prior to referral and were treated with curative or consolidative CHT and/or RT. CHT was carried out according to the CHOP or COP-Blam protocol. Median age was 60 years (29-85). Forty patients had tumor stage IE, 36 II1E and 16 II2E (Musshoff classification). MALT histology was present in 25, diffuse large-cell in 62, lymphoplasmocytic in 4 cases and follicular histology in 1 case. Five-year disease-specific survival was 93% both after primary CHT and after primary surgery (P = 0.8). Five-year relapse-free survival was 91% and 93%, respectively (P = 0.7). No patient experienced gastric perforation or bleeding during CHT. Primary CHT of localized gastric lymphoma is associated with a low risk of treatment-related complications. Survival was similar compared to patients initially treated with surgery. To avoid long-term sequelae after gastric resection, primary CHT is recommended as standard initial treatment in localized gastric lymphoma.

Estimating the optimal utilization rates of radiotherapy for hematologic malignancies from a review of the evidence

BACKGROUND

The objective of this study was to estimate the ideal proportion of new patients with lymphoma who should receive radiotherapy at some time during the course of their illness, based on the best evidence.

METHODS

Available evidence of the efficacy of radiotherapy in most clinical situations for lymphoma were identified through extensive literature reviews and treatment guideline searches. Epidemiologic data concerning the distribution of histologic type, disease stage, and other factors that influence the use of radiotherapy were identified. Decision trees were constructed to merge the evidence-based recommendations with the epidemiologic data to calculate the optimal proportion of patients who should receive radiotherapy according to the best available evidence. Actual radiotherapy utilization rates also were identified.

RESULTS

The proportion of patients with lymphoma in Australia that should receive radiotherapy at some point in their management, according to the best available evidence, was calculated at 65.0%. Multivariate analysis with a Monte Carlo simulation yielded a radiotherapy utilization rate of 64.4%. The actual utilization rates of radiotherapy for lymphoma reported in clinical practice were 22-29%, substantially lower than the optimal rate calculated in this project.

CONCLUSIONS

Further research will be required to identify why more patients who are diagnosed with lymphoma are not treated with radiotherapy.

Les lymphomes gastriques du MALT

INTRODUCTION

The stomach is the most common site involved in primary gastrointestinal lymphoma. Gastric lymphoma originates from the mucosa-associated lymphoïd tissue so called MALT. It comprises a group of distinctive clinicopathological entities which are important to consider for clinical management.

CURRENT KNOWLEDGE AND KEY POINTS

In recent years, new diagnostic tools and new treatment strategies have improved the overall prognosis. One of the most exciting recent discoveries is the hypothesis that an infection by a bacterium, Helicobacter pylori has a decisive role in gastric lymphoma.

FUTURE PROSPECTS AND PROJECTS

Recent advances, essentially due to molecular biology and cytogenetic studies may emerge with the understanding of pathogenesis and new prognostic factors of these different types of gastric lymphomas. It is the aim of our oncoming studies together with the evaluation of the new therapeutic options such as radiotherapy and monoclonal antibodies in prospective studies.

The diminishing role of surgery in the treatment of gastric lymphoma

OBJECTIVE

This article reviews the pathogenesis, diagnosis, and treatment of patients with primary gastric lymphoma, with special attention to the changing role of surgery.

SUMMARY BACKGROUND DATA

Primary gastric lymphomas are non-Hodgkin lymphomas that originate in the stomach and are divided into low-grade (or indolent) and high-grade (or aggressive) types. Low-grade lesions nearly always arise from mucosa-associated lymphoid tissue (MALT) secondary to chronic Helicobacter pylori (H. pylori) infection and disseminate slowly. High-grade lesions may arise from a low grade-MALT component or arise de novo and can spread to lymph nodes, adjacent organs and tissues, or distant sites.

METHODS

A review of the relevant English-language articles was performed on the basis of a MEDLINE search from January 1984 to August 2003.

RESULTS

About 40% of gastric lymphomas are low-grade, and nearly all these low-grade lesions are classified as MALT lymphomas. For low-grade MALT lymphomas confined to the gastric wall and without certain negative prognostic factors, H. pylori eradication is highly successful in causing lymphoma regression. More advanced low-grade lymphomas or those that do not regress with antibiotic therapy can be treated with combinations of H. pylori eradication, radiation therapy, and chemotherapy. Nearly 60% of gastric lymphomas are high-grade lesions with or without a low-grade MALT component. These lymphomas can be treated with chemotherapy and radiation therapy according to the extent of disease. Surgery for gastric lymphoma is now often reserved for patients with localized, residual disease after nonsurgical therapy or for rare patients with complications.

CONCLUSION

The treatment of gastric lymphoma continues to evolve, and surgical resection is now uncommonly a part of the initial management strategy.

The role of surgery in primary gastric lymphoma: results of a controlled clinical trial

OBJECTIVE

We began a controlled clinical trial to assess efficacy and toxicity of surgery (S), surgery + radiotherapy (SRT), surgery + chemotherapy (SCT), and chemotherapy (CT) in the treatment of primary gastric diffuse large cell lymphoma in early stages: IE and II1.

SUMMARY BACKGROUND DATA

Management of primary gastric lymphoma remains controversial. No controlled clinical trials have evaluated the different therapeutic schedules, and prognostic factors have not been identified in a uniform population.

PATIENTS AND METHODS

Five hundred eighty-nine patients were randomized to be treated with S (148 patients), SR (138 patients), SCT (153 patients), and CT (150 patients). Radiotherapy was delivered at doses of 40 Gy; chemotherapy was CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) at standard doses. International Prognostic Index (IPI) and modified IPI (MIPI) were assessed to determine outcome.

RESULTS

Complete response rates were similar in the 4 arms. Actuarial curves at 10 years of event-free survival (EFS) were as follows: S: 28% (95% confidence interval [CI], 22% to 41%); SRT: 23% (95% CI, 16% to 29%); that were statistically significant when compared with SCT: 82% (95% CI, 73% to 89%); and CT: 92% (95% CI, 84% to 99%) (P < 0.001). Actuarial curves at 10 years showed that overall survivals (OS) were as follows: S: 54% (95% CI, 46% to 64%); SRT: 53% (95% CI, 45% to 68%); that were statistically significant to SCT: 91% (95% CI, 85% to 99%); CT: 96% (95% CI, 90% to 103%)(P < 0.001). Late toxicity was more frequent and severe in patients who undergoing surgery. IPI and MIPI were not useful in determining outcome and multivariate analysis failed to identify other prognostic factors.

CONCLUSION

In patients with primary gastric diffuse large cell lymphoma and aggressive histology, diffuse large cell lymphoma in early stage SCT achieved good results, but surgery was associated with some cases of lethal complications. Thus it appears that CT should be considered the treatment of choice in this patient setting. Current clinical classifications of risk are not useful in defining treatment.

Surgical resection plus chemotherapy versus chemotherapy alone: comparison of two strategies to treat diffuse large B-cell gastric lymphoma

BACKGROUND

The usefulness of chemotherapy to treat gastric diffuse large B-cell lymphomas (DLBCL) is well known. Whether or not chemotherapy should be performed as the only treatment or after surgical resection is debated. The aim of this study was to compare two strategies: surgical resection plus chemotherapy versus chemotherapy alone.

PATIENTS AND METHODS

Between January 1988 and December 1996, 58 patients included in the trials promoted by the Groupe d'Etude des Lymphomes de l'Adulte (GELA) (LNH-87 and LNH-93) received chemotherapy and 48 included in the protocol of the Groupe d'Etude des Lymphomes Digestifs (GELD) underwent surgical resection followed by chemotherapy. They all presented with localized DLBCL (stage IE and IIE according to the Ann Arbor classification). From the GELA group, seven patients received additional radiotherapy. Gastrectomy was total in 27 of the 48 patients in the GELD group. In both groups chemotherapy included anthracyclin and alkylating agents. Chemotherapy was more intensive in the GELA group than in the GELD group.

RESULTS

In the GELA and the GELD groups, distribution according to sex ratio, age (>60 or < or = 60 years), ECOG performance status (> or = 2 or <2) and staging (IE or IIE) was similar. Univariate analysis comparing prognostic factors in both groups showed significant differences: serum lactate dehydrogenase level above normal (28.6% versus 2.4%, P = 0.001), tumor size >10 cm (28.6% versus 12.5%, P = 0.04), patients with International Prognostic Index (IPI) >1 (21.4% versus 11.1%, P = 0.168) and 5-year survival (79% versus 90%, P = 0.03). Multivariate analysis of prognostic factors with a Cox model showed that IPI was the only independent prognostic factor (odds ratio 3, P = 0.03). Consequently, patients with IPI 0-1 were selected for comparison between the GELA group (44 patients) and the GELD group (40 patients). There was no significant difference between the two groups. Median follow-up was 59 months (range 3-128). Estimates of 5-year survival rates and event-free survival rates were 90.5% versus 91.1% (P = 0.303) and 85.9% versus 91.6% (P = 0.187), respectively. In the GELA group, seven of 44 patients died: five from a lymphoma-unrelated cause and two from tumor progression. In the GELD group, four of 40 patients died: two of unrelated causes and two from tumor progression.

CONCLUSIONS

This study shows that in localized gastric DLBCL with IPI 0-1, a similar 5-year survival rate (>90%) is to be expected with either surgery plus chemotherapy or chemotherapy alone.

Marginal Zone B-cell Lymphoma (MALT Lymphoma)

The preferred terminology for mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach (variously referred to as MALT lymphoma, MALToma, low-grade MALToma, or pseudolymphoma) is marginal zone B-cell lymphoma (MZBL). MZBL, the hallmark of which is the lymphoepithelial lesion, develops as a consequence of Helicobacter pylori infection in susceptible individuals. In general, MZBL is slow growing, can remain localized for years, and has an excellent prognosis. Staging involves endoscopy with biopsy, computed tomography scanning, and endoscopic ultrasound. In patients with limited disease, eradication of H. pylori leads to remission. In patients who fail eradication therapy or have more extensive disease, surgery, chemotherapy, and radiation alone and in various combinations have been used successfully.

Primary gastric lymphoma

AIM: The purpose of this review is to describe the various aspects of primary gastric lymphoma and the treatment options currently available.

METHODS: After a systematic search of Pubmed, Medscape and MDconsult, we reviewed and retrieved literature regarding gastric lymphoma.

RESULTS: Primary gastric lymphoma is rare however, the incidence of this malignancy is increasing. Chronic gastritis secondary to Helicobacter pylori (H pylori) infection has been considered a major predisposing factor for MALT lymphoma. Immune histochemical marker studies and molecular biology utilizing polymerase chain reaction have facilitated appropriate diagnosis and abolished the need for diagnostic surgical resection. Advances in imaging techniques including Magnetic Resonance Imaging (MRI) and Endoscopic Ultrasonography (EUS) have helped evaluation of tumor extension and invasion. The clinical course and prognosis of this disease is dependent on histopathological sub-type and stage at the time of diagnosis. Controversy remains regarding the best treatment for early stages of this disease. Chemotherapy, surgery and combination have been studied and shared almost comparable results with survival rate of 70%-90%. However, chemotherapy possesses the advantage of preserving gastric anatomy. Radiotherapy alone has been tried and showed good results. Stage IIIE, IVE disease treatment is solely by chemotherapy and surgical resection has been a remote consideration.

CONCLUSION: We conclude that methods of diagnosis and staging of the primary gastric lymphoma have dramatically improved. The modalities of treatment are many and probably chemotherapy is superior because of high success rate, preservation of stomach and tolerable complications.

Gastrointestinal lymphoma

The ability to make treatment recommendations for patients with gastrointestinal lymphoma is hampered by a lack of prospective trials and by a lack of uniformity in classification and staging. Patients with gastric diffuse large B-cell lymphoma have traditionally been treated with surgery and many physicians continue to recommend this approach. However, recent data suggest that these patients can be treated with combination chemotherapy regimens in the same manner as patients with nodal presentations of diffuse large B-cell lymphoma. There is evidence to suggest that adjuvant radiotherapy may improve the outcome for these patients. The recognition that extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue is a distinct clinicopathologic entity and the elucidation of the pathogenic role of Helicobacter pylori has revolutionized the treatment of these gastric lymphomas. Patients with localized disease should be managed with antibiotic therapy initially. Radiation therapy is extremely effective for these patients, but it should probably be reserved for patients who fail anti-H. pylori treatment.

Intestinal non-Hodgkin's lymphoma: a multicenter prospective clinical study from the German Study Group on Intestinal non-Hodgkin's Lymphoma

PURPOSE

Intestinal non-Hodgkin's lymphomas are not well characterized. We therefore studied prospectively their clinical features and response to standardized therapy.

PATIENTS AND METHODS

Fifty-six patients with primary intestinal lymphoma were included in a prospective, nonrandomized multicenter study. Lymphoma resection was recommended and staging was performed according to the Ann Arbor classification. Patients were scheduled to receive six cycles of cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) chemotherapy, and at stages EIII to EIV, they received additional involved-field radiotherapy. Corticosteroids were used in patients who could not receive chemotherapy.

RESULTS

Thirty-five patients had intestinal T-cell lymphoma (ITCL), 21 patients had intestinal B-cell lymphoma (IBCL; 18 diffuse large-cell lymphomas, two marginal-cell lymphomas, and one follicle-center lymphoma). Thirty-four patients at stages EI to EII (14 ITCL and 20 IBCL) and nine patients at stages EIII to EIV (all ITCL) received chemotherapy. No patient in stages EIII to EIV received radiotherapy, because death occurred in 12 of 14 patients. Two-year cumulative survival in patients with IBCL was 94% (95% CI, 82% to 100%) and higher than in patients with ITCL (28% [95% CI, 13% to 43%]; P <.0001), even when only stages EI to EII were considered (ITCL, 37.5% [95% CI, 16.5% to 58.5%]; P <.0001). IBCL patients compared with ITCL patients were at lower lymphoma stages (P <.01), had higher Karnofsky status (P <.005), had intestinal perforation less often (P <.05), required emergency operation less often (P <.05), received CHOP (P <.05) more often, and reached complete remission (P <.0005) more frequently.

CONCLUSION

IBCL patients at stages EI and EII respond well to chemotherapy, but the prognosis and treatment of ITCL patients is unsatisfactory.

Primary gastrointestinal lymphoma in Japan: a clinicopathologic analysis of 455 patients with special reference to its time trends

BACKGROUND

An optimal treatment modality for patients with primary gastrointestinal lymphoma has not yet been established. This study aimed to elucidate the clinicopathologic features of this disease and the influence of therapeutic modalities on the prognosis in Japanese patients

METHODS

The clinicopathologic features of 455 patients with primary gastrointestinal lymphoma were investigated retrospectively regarding treatment modalities and time trends.

RESULTS

This study comprised 342 patients (75%) with gastric lymphoma, 96 patients (22%) with intestinal lymphoma, and 17 patients (4%) with both gastric and intestinal lymphoma. Two hundred thirty-one (51%) patients were classified as having low-grade B-cell lymphoma including 200 marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) type, 185 (41%) patients were classified as having high-grade B-cell lymphoma including 76 diffuse large cell lymphoma plus MALT lymphoma, and 39 (9%) patients were classified as having T-cell lymphoma. The frequency of nonsurgical treatment, including Helicobacter pylori eradication, chemotherapy, and radiation, increased during the latest decade. Patients who received nonsurgical treatment showed a better overall survival than those treated by surgery, but event-free survival did not differ between two groups. Cox multivariate analysis revealed that early stage, younger age, gastric localization, B-cell phenotype, and absence of B symptoms were independent prognostic factors for better overall and event-free survivals. Mucosa-associated lymphoid tissue-derived lymphoma was also an independent prognostic factor for event-free survival, but not for overall survival.

CONCLUSIONS

Nonsurgical treatment may be an optimal therapeutic modality for patients with primary gastrointestinal lymphoma.

Helicobacter pylori and carcinogenesis of gastric B-cell lymphomas

Primary non-Hodgkin's lymphomas of the stomach are associated with Helicobacter pylori infection. We analyzed gastric lymphoma onset data with respect to prior H. pylori infections based on the multistage theory of carcinogenesis. This theory provides a link between epidemiological data and biological processes. The study involved 133 patients, aged 29-75 years, diagnosed with marginal zone B-cell lymphoma (MZBL) and diffuse large cell B-cell lymphoma (DLBL). A 2-parametric Weibull model was applied to MZBL and DLBL onset data. Median age of diagnosis of MZBL (DLBL) was 59 years (55 years) in males and 65.5 years (64 years) in females. Infection with H. pylori was found in 81.3% (59.5%) of the patients diagnosed with MZBL (DLBL). Lymphoma latency data were fitted to Weibull distributions with a shape parameter of 5.7 for MZBL cases and 4.2 for DLBL. The shape parameter that indicates the number of steps in carcinogenesis was approximately independent of the status of infection with H. pylori in DLBL in contrast to MZBL. It was shown that gastric lymphoma onset data can be described by Weibull distribution functions. The findings support the hypothesis that MZBL and DLBL have different lines of development. There is indication of stronger antigen dependency in the carcinogenesis of MZBL in comparison to DLBL.

Clinicopathological features of gastric B-cell lymphoma: a series of 317 cases

The stomach is a common site of extranodal malignant lymphoma. Here we examined the clinicopathological features of 317 gastric B-cell lymphomas and characterized the differences among low-grade mucosa-associated lymphoid tissue (MALT) lymphomas (LG), high-grade MALT lymphomas (HG), follicular lymphomas (FL) and diffuse large B-cell lymphomas (DL). Cases included 126 DL, 71 HG, 98 LG, 10 FL, three Burkitt's lymphoma and nine of undefined type. The age range of patients was as follows: LG, 14-96 years (mean, 61.1); HG, 20-87 years (mean, 63.9); DL, 16-88 years (mean, 62.8); and FL, 54-76 years (mean, 65.5). There were no differences in age with respect to tumor type. There were more women patients with LG (female:male, 55:43), while males predominated among DL patients (54:72). The sexes were represented almost equally in HG cases (34:37). Histological findings, especially in DL tumors, correlated significantly to the gross appearance of mass formation. Dutcher bodies were encountered mainly in HG or LG cases. Our results showed no differences in age, sex or site of disease between LG, HG and DL tumors. However, the grade of malignancy correlated strongly to gross appearance. Dutcher bodies were important for the diagnosis of gastric MALT lymphoma.

Diagnostic accuracy of EUS in the local staging of primary gastric lymphoma: results of a prospective, multicenter study comparing EUS with histopathologic stage

BACKGROUND

Grade of malignancy and stage of disease are the decisive prognostic factors and therapeutic determinants in primary gastric lymphoma. It is supposed that EUS allows determination of depth of tumor infiltration and perigastric lymph node involvement, thus defining stages I1, I2, and II1. This multicenter study evaluated the accuracy of EUS in the staging of gastric lymphoma.

METHODS

Data from preoperative EUS procedures performed at 34 centers were compared with the histopathologic stage of resection specimens in 80 patients with newly diagnosed primary gastric lymphoma. Ten patients with stage II2 were excluded from analysis because EUS is inappropriate for the evaluation of nonregional lymph node involvement.

RESULTS

EUS correctly classified the lymphoma in 37 of 70 patients (53%). Sensitivity of EUS was as follows: stage I1, 67% (95% CI [38%, 88%]; p = 0.01); stage I2, 83% (95% CI [52%, 98%]; p = 0.01); and stage II1, 71% (95% CI [49%, 87%]; p = 0.02).

CONCLUSION

The accuracy of EUS in the local staging of gastric lymphoma has to be improved if nonsurgical treatment strategies based on the grade of malignancy and stage of the disease are to be used. Because most of the participating centers performed EUS in relatively few patients, no conclusion could be drawn with respect to accuracy in relation to EUS experience available at each center or technical considerations with respect to the types of instruments used.

The importance of endoscopic ultrasonography in the management of low-grade gastric mucosa-associated lymphoid tissue lymphoma

BACKGROUND

Anti-Helicobacter pylori therapy has been reported to cause regression of low-grade gastric mucosa-associated lymphoid tissue lymphoma in a high percentage of patients. However, in some patients, these lesions persist despite antibiotic treatment.

AIM

To determine the various endosonographic findings that may predict the regression of low-grade gastric mucosa-associated lymphoid tissue lymphoma post-antibiotics.

METHODS

Seventy-six patients with Helicobacter pylori-positive gastric mucosa-associated lymphoid tissue lymphoma were studied. Follow-up data were available on 51 patients. All patients were treated with antibiotics. Participants underwent pre- and post-anti-Helicobacter pylori therapy endoscopy with gastric biopsies, followed by endoscopic ultrasonography examination of the stomach.

RESULTS

Helicobacter pylori was eradicated in 45 of 51 (88%) patients. At the 2-year follow-up, complete regression of mucosa-associated lymphoid tissue lymphoma was seen in 28 of 51 (55%) patients: 12 of 16 (75%) patients in stage T1m N0, 11 of 19 (58%) patients in stage T1sm N0, four of eight (50%) patients in stages T1m N1 and T1sm N1, and one of four (25%) patients in stage T2 N0. None of the stage T2 N1 patients achieved clinical regression.

CONCLUSIONS

Endoscopic ultrasonography evaluation of gastric mucosa-associated lymphoid tissue lymphoma plays a pivotal role in the initial staging and post-treatment follow-up evaluation of these lesions. Accurate staging is essential in the determination of the optimal treatment modality.

Treatment of extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue type with cladribine: a phase II study

PURPOSE

As chemotherapy has not been extensively studied in patients with lymphoma of the mucosa-associated lymphoid tissue (MALT), we initiated a prospective study to evaluate the activity of the nucleoside analog cladribine (2-chlorodeoxyadenosine [2-CdA]) in this disease.

PATIENTS AND METHODS

Patients with histologically verified MALT-type lymphoma were enrolled. 2-CdA was administered at a dose of 0.12 mg/kg body weight on 5 consecutive days, as a 2-hour infusion. Cycles were repeated every 4 weeks for a maximum of six cycles.

RESULTS

Nineteen patients with gastric and seven patients with extragastric MALT lymphoma were enrolled. All patients were chemotherapy-naive, and two had been locally irradiated before systemic relapse of the lymphoma. A total of 102 cycles was administered to our patients (median number of cycles per patient, four). All 25 assessable patients responded to treatment: 21 patients (84%) achieved complete remission (CR) and four patients achieved partial remission. All patients (100%) with gastric presentation, but only three patients (43%) with extragastric presentation, achieved CR. Toxicities were moderate and mainly hematologic and required dose reduction and/or premature discontinuation of therapy in only three cases. Two patients died from vascular events, one shortly after the first cycle because of myocardial infarction and the other from stroke 3 months after the second course. Three patients relapsed after 13, 18, and 22 months and one patient showed progressive disease after 15 months. At present, 24 patients are alive at a median follow-up time of 32 months.

CONCLUSION

Our data demonstrate that 2-CdA is highly effective in inducing CR in 84% of patients with MALT-type lymphoma.

Minimal residual low-grade gastric MALT-type lymphoma after eradication of Helicobacter pylori

Helicobacter pylori eradication is the initial treatment of choice in localised low-grade gastric MALT (mucosa-associated lymphoid-tissue)-type lymphoma. We describe the natural course of seven patients who refused further oncological treatment for persistent lymphoma after successful eradication of H pylori. Despite persistent clonality, neither lymphoma progression nor high-grade transformation arose during a mean observation period of 34 (range 22-44) months. In view of the favourable course of these patients, a watch-and-wait strategy could be a valid approach to management of this disease.

High-grade B-cell lymphoma arising in mucosa-associated lymphoid tissue of the duodenum

Duodenal mucosa-associated lymphoid tissue lymphoma is a rare neoplasm. We report a case of a 70-year-old man with non-Hodgkin's lymphoma located in the descending duodenum that was not associated with Helicobacter pylori infection of the stomach. A surgical resection due to obstruction of the bowel lumen above the ligament of Treitz was performed. No invasion into the adjacent structure was confirmed at surgery. The pathological examination showed an infiltration of the duodenal mucosa and submucosa with B lymphocytes. Monoclonal proliferation of the lymphoid tissue was demonstrated by polymerase chain reaction. The histological appearance and the demonstration of monoclonality fulfilled the criteria for malignant high-grade B-cell lymphoma arising from mucosa-associated lymphoid tissue.

Incidence of gastric B-cell lymphomas: a population-based study in Germany

BACKGROUND

While the clinical and experimental knowledge concerning gastric lymphomas is increasing, there is a scarcity of epidemiological data.

PATIENTS AND METHODS

A population-based sample of patients in Franconia and Saarland in Germany was collected from a clinical trial, hospital archives and a cancer registry.

RESULTS

Over a period of 3 years, 94 patients with primary gastric lymphoma were recorded out of a total population of 3.5 million. The standardised incidence rates in Saarland and Franconia were 0.7 and 0.8 cases per 100 000, respectively. Patients were predominantly from higher age groups (mean age 62.1 years) and the incidence in men was slightly more than in women (P <0.03). The distribution of histological subtypes in Franconia was as follows: marginal zone B-cell lymphomas (MZBL), 58%; diffuse large-cell B-cell lymphoma (DLBL), 33%; and mixed forms, 9%. Helicobacter pylori could be detected histologically in 84% of all cases, 95% of MZBL cases and 68% of DLBL cases.

CONCLUSIONS

Incidence rates of gastric lymphoma in Germany were similar to that in other European countries, except England, where rates are lower. The subtype-specific differences of H. pylori infection rates could be due to differences in carcinogenesis or to secondary changes during malignant transformation.

Interobserver agreement in staging gastric malt lymphoma by EUS

BACKGROUND

EUS is highly accurate for staging gastric lymphoma. Because stage correlates to outcome, interobserver agreement is mandatory. However, previous studies suggest that interobserver agreement might vary according to T-stage. A multicenter evaluation of observer agreement with respect to endosonographic staging of gastric mucosa-associated lymphoid tissue (MALT) lymphoma was therefore conducted.

METHODS

Fifty-four patients were studied; 42 were also evaluated after eradication of Helicobacter pylori infection. EUS was performed at different institutions by 10 experienced endosonographers who collected the best photographs for each examination. Interobserver agreement was estimated with kappa statistics.

RESULTS

Overall interobserver agreement for T-stage was fair, both before and after treatment (kappa = 0.38 and kappa = 0.37, respectively). Overall interobserver agreement for N-stage was substantial before treatment, but only fair after treatment (kappa = 0.63 and kappa = 0.34, respectively). The lowest values of agreement occurred with T1sm (submucosa) and T2 stage lesions.

CONCLUSIONS

Interobserver agreement for staging of gastric MALT lymphoma by EUS is suboptimal before as well as after treatment of H pylori infection. This evidence suggests that gastric EUS may be more difficult technically compared with EUS of other organs. Lack of agreement is crucial because it influences the choice of therapy and assessment of response to treatment. Good interobserver agreement would permit better communication concerning the clinical status of patients, comparison of the results of different studies, and stratification of patients within clinical trials.

A clinicopathological study of 152 surgically treated primary gastric lymphomas with survival analysis of 109 high grade tumours

AIMS

To describe the clinicopathological features of a large number of surgically treated and followed up primary gastric lymphomas and thereby gain a better understanding of their biology, with particular reference to the prognostic factors of high grade tumours.

METHODS

A retrospective study of 152 patients.

RESULTS

High grade gastric lymphomas, both pure and with a residual low grade component, differed from low grade mucosa associated lymphoid tissue (MALT)-type lymphomas in that they were more frequently large, ulcerated, at an advanced stage, and highly proliferating. In addition, patients were older and had a worse outcome. The prognosis of high grade lymphomas was influenced by patient age, tumour stage, depth of infiltration in the gastric wall, and the invasion of adjacent organs. Adjuvant postsurgical treatment prolonged survival only in patients with advanced stage and deep neoplastic infiltration.

CONCLUSIONS

There is a sharp distinction between low grade MALT-type lymphomas and tumours with a high grade component, justifying their different treatment approach. The postsurgical management of high grade lymphomas should be based on the accurate evaluation of the neoplastic extension.

Gastric MALT lymphoma: from aetiology to treatment

The development of gastric mucosa-associated lymphoid tissue (MALT) lymphoma is dependent on Helicobacter pylori infection. Bacterial colonisation of the gastric mucosa triggers lymphoid infiltration and the formation of acquired MALT. The bacterial infection induces and sustains an actively proliferating B-cell population through direct (autoantigen) and indirect (intratumoral T cells specific for H. pylori) immunological stimulation. Moreover, the bacterial infection provokes a neutrophilic response, which causes the release of oxygen free radicals. These reactive species may promote the acquisition of genetic abnormalities and malignant transformation of reactive B cells. A transformed clone carrying the translocation t(1;18)(q21;q21) forms a MALT lymphoma, the growth of which is independent of H. pylori and will not respond to bacterial eradication. Malignant clones without t(11;18)(q21;q21), but with other genetic abnormalities, such as trisomy 3 or microsatellite instability, depend critically on immune stimulation mediated by H. pylori for their clonal expansion. In the early stages, the tumour can be successfully treated by eradication of the bacterium, whereas at later stages the tumour may escape its growth dependency through acquisition of additional genetic abnormalities such as t(1;14)(p22;q32) and t(1;2)(p22,p12) involving the BCL-10 gene. Finally, further genetic abnormalities, such as inactivation of the tumour suppressor genes, p53 and p16, can lead to high-grade transformation. Detection of these abnormalities may help with the clinical management of patients with gastric MALT lymphoma.

Long-term follow-up of gastric MALT lymphoma after H. pylori eradication

For almost 10 years, we have been familiar with the concept of mucosa-associated lymphoid tissue (MALT)-type lymphoma of the stomach caused by chronic Helicobacter pylori infection. Many epidemiologic, biologic, and molecular genetic studies have implicated H. pylori for its role in lymphoma genesis. Since the first reports on complete remission of gastric MALT lymphomas after cure of bacterial infection, many clinical studies have investigated the effect of eradicating H. pylori on the course of MALT lymphoma, and indeed were able to confirm remission of the lymphoma. To date, more than 650 patients worldwide have been treated for gastric MALT lymphoma with antibiotics, and we have gained many new insights concerning the biologic behavior of this disease, especially from the deepened knowledge of cytogenetics. Furthermore, factors relevant for the prediction of treatment outcome have been identified, which has helped to stratify patients into risk groups.

Gastric surgery

Significant advances in the role of gastric surgery in the management of disease in the past year have focused on three broad areas: morbid obesity, gastric cancer, and peptic ulcer disease. Although vertical banded gastroplasty and Roux-en-Y gastric bypass are the two procedures most commonly used in the United States to induce weight loss in the morbidly obese patient, long-term follow-up continues to support the durability of the gastric bypass in maintaining a sustainable outcome with a minimum of complications. It is not surprising, therefore, that increasing interest has accrued in simplifying this operation and decreasing potential complications even further by employing laparoscopic technology. In the area of gastric cancer, several reports have provided important new information regarding its pathogenesis, factors influencing long-term survival, and strategies for management when diagnosed early. Finally, in patients developing the complications of peptic ulcer disease (eg, obstruction and perforation), conservative management has been emphasized over more radical traditional approaches. This review highlights these advances.

Extranodal lymphoma of MALT-type: perspective at the beginning of the 21st century

Extranodal lymphomas arising from mucosa associated lymphoid tissue (MALT) have become a focus of interest in recent years due to their unique pathological and clinical properties. The link between Helicobacter pylori and the development of gastric MALT-type lymphoma has revolutionized treatment options as up to 80% of patients with early gastric MALT-type lymphoma achieve complete remission of the tumor following eradication of H. pylori. As opposed to surgical intervention, which has been the preferred form of treatment in the past, organ conserving approaches are increasingly being applied, as both irradiation and chemotherapy have given excellent results. However, mature data from prospective, randomized studies taking into account the concept of MALT lymphoma as a distinct entity are still lacking in order to define the optimal approach to the management of MALT-type lymphoma.