A retrospective analysis of primary gastric diffuse large B-cell lymphoma with or without concomitant mucosa-associated lymphoid tissue (MALT) lymphoma components. Ann Hematol. 2013;92:807-815. [PMID: 23417758 DOI: 10.1007/s00277-013-1701-9]

Primary gastric non-Hodgkin lymphomas: Recent advances regarding disease pathogenesis and treatment

Primary gastric lymphomas (PGLs) are distinct lymphoproliferative neoplasms described as heterogeneous entities clinically and molecularly. Their main histological types are diffuse large B-cell lymphoma (DLBCL) or mucosa-associated lymphoma tissue. PGL has been one of the main fields of clinical research of our group in recent years. Although gastric DLBCLs are frequent, sufficient data to guide optimal care are scarce. Until today, a multidisciplinary approach has been applied, including chemotherapy, surgery, radiotherapy or a combination of these treatments. In this minireview article, we provide an overview of the clinical manifestations, diagnosis and staging of these diseases, along with their molecular pathogenesis and the most important related clinical published series. We then discuss the scientific gaps, perils and pitfalls that exist regarding the aforementioned studies, in parallel with the unmet need for future research and comment on the proper methodology for such retrospective studies. Aiming to fill this gap, we retrospectively evaluated the trends in clinical presentation, management and outcome among 165 patients with DLBCL PGL who were seen in our institutions in 1980-2014. The study cohort was divided into two subgroups, comparing the main 2 therapeutic options [cyclophosphamide doxorubicin vincristine prednisone (CHOP) vs rituximab-CHOP (R-CHOP)]. A better outcome with immunochemotherapy (R-CHOP) was observed. In the next 2 mo, we will present the update of our study with the same basic conclusion.

Clinical features and outcomes of diffuse large B-cell lymphoma based on nodal or extranodal primary sites of origin: Analysis of 1,085 WHO classified cases in a single institution in China

Objective

To explore the clinicobiologic features and outcomes of diffuse large B-cell lymphoma (DLBCL) patients in China according to the primary site.

Methods

A total of 1,085 patients diagnosed with DLBCL in National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College during a 6-year period were enrolled. Their clinical characteristics and outcomes were analyzed according to the primary site.

Results

In the 1,085 patients, 679 (62.6%) cases were nodal DLBCL (N-DLBCL) and 406 cases (37.4%) were extranodal DLBCL (EN-DLBCL). The most common sites of N-DLBCL were lymphonodus (64.8%), Waldeyer's ring (19.7%), mediastinum (12.8%) and spleen (2.7%), while in EN-DLBCL, stomach (22.4%), intestine (16.0%), nose and sinuses (8.9%), testis (8.4%), skin (7.9%), thyroid (6.9%), central nervous system (CNS) (6.4%), breast (5.7%), bone (3.4%), and salivary gland (2.7%) were most common. N-DLBCL patients tend to present B symptoms, bulky disease, and elevated LDH more often, while age >60 years, extranodal sites >1, Ann Arbor stage I or II, bone marrow involvement, and Ki-67 index >90% were usually seen in EN-DLBCL. The 5-year overall survival (OS) rate and progression-free survival (PFS) rate for all patients were 62.5% and 54.2%. The 5-year OS rate for patients with N-DLBCL and EN-DLBCL were 65.5% and 56.9% (P=0.008), and the 5-year PFS were 57.0% and 49.0% (P=0.020). Waldeyer's ring originated DLBCL possessed the highest 5-year OS rate (83.6%) and PFS rate (76.9%) in N-DLBCL. The top five EN-DLBCL subtypes with favorable prognosis were stomach, breast, nose and sinuses, lung, salivary gland, with 5-year OS rate: 70.3%, 69.6%, 69.4%, 66.7% and 63.6%, respectively. While CNS, testis, oral cavity and kidney originated EN-DLBCL faced miserable prognosis, with 5-year OS rate of 26.9%, 38.2%, and 42.9%.

Conclusions

In our study, primary sites were associated with clinical characteristics and outcomes. Compared with EN-DLBCL, N-DLBCL had better prognosis.

The cell-of-origin classification of diffuse large B cell lymphoma in a Korean population by the Lymph2Cx assay and its correlation with immunohistochemical algorithms

Cell-of-origin (COO) classification of diffuse large B cell lymphoma (DLBCL) is increasingly important due to its prognostic significance and the development of subtype-specific therapeutics. We compared the clinical utility of the Lymph2Cx assay against four widely used immunohistochemical algorithms in 150 R-CHOP-treated DLBCL patients using archival tissue. In contrast to the predominance of germinal center B cell-like (GCB) subtype in Western populations, Lymph2Cx assay classified more than half of the Korean cases as the activated B cell-like (ABC) subtype (ABC, 83/150 [55.3%]; GCB, 51/150 [34.0%]; unclassifiable, 16/150 [10.7%]). Predominance of ABC subtype tended to be more pronounced in the nodal lymphomas than in the extranodal lymphomas. However, among the primary extranodal sites, ABC subgroups predominated in primary testicular, breast, and adrenal gland lymphomas. The classification of COO by Lymph2Cx assay did not show any significant association with clinical parameters. The overall concordance rates of the immunohistochemical algorithms with the Lymph2Cx ranged from 78.0 to 84.3%. However, 47.1-66.7% of the cases of the Lymph2Cx-defined GCB subgroup were misclassified as the non-GCB class by the IHC algorithms. The survival of Lymph2Cx-classified COO subtypes was not significantly different in the present cohort. In conclusion, ABC subtype predominated over GCB in Korean patients. There are significant discrepancies between the immunohistochemistry and Lymph2Cx classifications, especially in GCB subtype.

Histological transformation from gastric mucosa-associated lymphoid tissue lymphoma to gastric diffuse large B-cell lymphoma

This study evaluated the clinical features, treatment and prognosis in Chinese patients with histological transformation (HT) from gastric mucosa-associated lymphoid tissue lymphoma to gastric diffuse large B-cell lymphoma. We reviewed the medical records of 71 patients diagnosed with HT between 2001 and 2013, retrospectively. Patients had a median age of 56 years. The ratio of sex (male:female) was 1.3:1. The clinical course was often insidious, lacking specific clinical presentation. Macroscopically, the antrum was the most commonly involved site. Thirty-one patients (45%) presented at stage I, and 25 (35%) presented with local (18/71, 25%) or distant (7/71, 10%) nodal involvement. There were also stage IIE (9/71, 12%) and stage IV (6/71, 8%) patients with advanced stages. For all 71 patients, the 5-year progression-free survival (PFS) and overall survival (OS) estimates were 50 and 56%, respectively. There was no statistical difference in 5-year PFS and OS estimates between patients receiving Helicobacter pylori (H. pylori) containing eradication (HPE) (p=0.189) and those receiving non-HPE (p=0.359). Upon the Cox regression model, advanced stages were the only independent prognostic factors associated with shorter PFS, and m-IPI was independently associated with shorter PFS and OS. There was no specific clinical manifestation for patients with HT. HPE is thus a promising therapeutic approach for such patients. Moreover, advanced stages and m-IPI significantly influenced patient outcome.

Role of follow-up endoscopic examination in treatment response assessment for patients with gastric diffuse large B cell lymphoma

OBJECTIVE

According to lymphoma guidelines, gastric diffuse large B cell lymphoma (DLBCL) patients should undergo regular computed tomography (CT) and/or positron emission tomography (PET) examinations to assess treatment response. Endoscopic examinations are not indicated in the guidelines. The aim of this study was to investigate the utility of endoscopic examinations during and after treatment for DLBCL.

METHODS

We reviewed the patients diagnosed with gastric DLBCL at Seoul St. Mary's Hospital. All patients underwent endoscopy and radiologic examinations at every follow-up appointment. Radiologic response was defined according to World Health Organization criteria and endoscopic response was determined based on the Groupe d'Etude des Lymphomes de l'Adult grading system that is widely used in post-treatment evaluation of gastric MALT lymphoma.

RESULTS

Forty-five patients were analyzed. Within a median follow-up period of 34 months, 35 patients achieved both radiologic and endoscopic complete remission (CR). The median times to endoscopic and radiologic CR were not significantly different (21 versus 16 weeks, p = 0.118). However, in 25 patients with stage I disease, endoscopic CR [median (range), 20 (11-36)] was achieved later than radiologic CR [median (range), 13 (8-36)] (p = 0.027). Among 40 patients who achieved radiologic CR, 35 patients who also achieved endoscopic CR maintained remission during the follow-up. Two of the five patients who achieved radiologic CR without endoscopic CR experienced recurrence.

CONCLUSIONS

In gastric DLBCL patients, endoscopic response does not always correlate with radiologic response and might predict disease recurrence. We suggest that follow-up endoscopic examination with biopsy should be performed in addition to radiologic examination.

The origin and targeting of mucosa-associated lymphoid tissue lymphomas

PURPOSE OF REVIEW

Extranodal mucosa-associated lymphoid tissue (MALT lymphoma) is a distinct clinical-pathological entity that can be distinguished from other lymphomas by a number of unique features, including their location in various extranodal sites, being preceded by chronic inflammatory or infection processes; a characteristic histopathological picture; and the presence of exclusive chromosomal translocations which increase MALT1 proteolytic activity to promote constitutive NF-κB signaling and eventually drive lymphomagenesis.

RECENT FINDINGS

This review explores the major molecular and cellular events that participate in MALT lymphoma pathogenesis, focusing on gastric MALT lymphoma as a model of chronic inflammation-induced tumor development. In addition, the pivotal roles of activated MALT1 protease, its substrate TNFAIP3/A20, and the MyD88 adaptor protein in abnormally triggering downstream NF-κB pathway are overviewed. These new insights provide a mechanistic basis for using novel therapies targeting MALT1 protease or IRAK4 kinase activities. Finally, the putative cellular origin of MALT lymphomas is also discussed.

SUMMARY

Over the last decade, unraveling the biological complexity of MALT lymphomas has shed light on the fundamental cellular and molecular aspects of the disease that are to be translated into clinical diagnostics and therapy.

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.

Role of Helicobacter pylori in gastric mucosa-associated lymphoid tissue lymphomas

Mucosa-associated lymphoid tissue (MALT) lymphoma is an indolent extranodal marginal zone B-cell lymphoma, originating in acquired MALT that is induced in mucosal barriers as part of a normal adaptive immune response to a chronic immunoinflammatory stimulus, most notably chronic infection by Helicobacter pylori (H. pylori). This antigenic stimulation initially leads to lymphoid hyperplasia; the acquisition of additional genetic aberrations culminates in the activation of intracellular survival pathways, with disease progression due to proliferation and resistance to apoptosis, and the emergence of a malignant clone. There are descriptions of MALT lymphomas affecting practically every organ and system, with a marked geographic variability partially attributable to the epidemiology of the underlying risk factors; nevertheless, the digestive system (and predominantly the stomach) is the most frequently involved location, reflecting the gastrointestinal tract’s unique characteristics of contact with foreign antigens, high mucosal permeability, large extension and intrinsic lymphoid system. While early-stage gastric MALT lymphoma can frequently regress after the therapeutic reversal of the chronic immune stimulus through antibiotic eradication of H. pylori infection, the presence of immortalizing genetic abnormalities, of advanced disease or of eradication-refractoriness requires a more aggressive approach which is, presently, not consensual. The fact that MALT lymphomas are rare neoplasms, with a worldwide incidence of 1-1.5 cases per 10⁵ population, per year, limits the ease of accrual of representative series of patients for robust clinical trials that could sustain informed evidence-based therapeutic decisions to optimize the quality of patient care.