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

Table 1 World Health Organization-based classification of mucosa-associated lymphoid tissue lymphomas

Hierarchical classification

Tumors of hematopoietic and lymphoid tissue

Mature B-cell neoplasms

Non-Hodgkin (B-cell) lymphomas

Marginal zone (B-cell) lymphomas

Extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue

Hierarchical classification of mucosa-associated lymphoid tissue lymphomas, according to the 2008 World Health Organization definitions. Adapted from Swerdlow et al[5], 2008.

Table 2 Recurrent chromosomal translocations described in mucosa-associated lymphoid tissue lymphomas

Translocation	Fusion protein
t(11;18) (q21;q21)	API2-MALT1
t(1;14) (p22;q32)	BCL10-IGH
t(1;2) (p22;p12)	BCL10-IGK
t(14;18) (q32;q21)	IGH-MALT1
t(3;14) (p14;q32)	FOXP1-IGH

API2: Apoptosis inhibitor 2; MALT1: Mucosa-associated lymphoid tissue translocation protein 1; BCL10: B-cell chronic lymphocytic leukemia/lymphoma protein 10; IGH: Immunoglobulin heavy chain; IGK: Immunoglobulin kappa light chain; FOXP1: Forkhead box protein P1.

Table 3 Useful phenotypic markers for the differential diagnosis of mucosa-associated lymphoid tissue lymphoma

Antigen	Notes
sIg+	B-cell receptor
CD19+	Pan-B-cell marker
CD20+	Pan-B-cell marker
CD22+	Pan-B-cell marker
CD79a+	Pan-B-cell marker
CD5-	Positive in CLL/SLL
CD10-	Positive in follicular lymphoma
CD23-	Positive in CLL/SLL
Cyclin D1-	Positive in mantle cell lymphoma

CD: Cluster of differentiation; sIg: Surface immunoglobulin; CLL/SLL: Chronic lymphocytic leukemia/small lymphocytic lymphoma.

Table 4 Association between abdominal computerized tomography findings and the likelihood of low-grade and high-grade lesions

Low-grade lesions	High-grade lesions
Normal scans	Abnormal scans
Gastric wall thickening < 5-10 mm	Diffuse gastric wall thickening > 10 mm
Small depressed lesions with vague margins	Well-demarcated masses with homogeneous attenuation and mild contrast enhancement
	Perigastric adenopathies more likely

Adapted from Hayashi et al[76], 2010.

Table 5 Comparison of four frequently used staging systems for primary gastrointestinal lymphomas

Tissue invasion	Ann arbor	Radaszkiewicz	Lugano	Paris
Gastrointestinal tract	IE	IE	I	T1 N0 M0
Mucosa or submucosa	IE	IE1	I	T1 N0 M0
Mucosa	IE	IE1	I	T1m N0 M0
Submucosa	IE	IE1	I	T1sm N0 M0
Muscularis propria or subserosa	IE	IE2	I	T2 N0 M0
Serosa	IE	IE2	I	T3 N0 M0
Intra-abdominal extension			II
Adjacent tissues or organs	IE	IE	IIE	T4 N0 M0
Regional lymph nodes	IIE	IIE	II1	T1 N1 M0
Infradiaphragmatic distal lymph nodes	IIE	IIE	II2	T1 N2 M0
Disseminated disease			IV
Supradiaphragmatic lymph nodes	IIIE	IIIE	IV	T1 N3 M0
Non-contiguous gastrointestinal2	IVE	IVE	IV	T1 N1 M1
Non-contiguous metastasis3	IVE	IVE	IV	T1 N1 M2
Marrow involvement	IVE	IVE	IVE	T1 N1 M1B1

In the case of synchronous lesions originating in the gastrointestinal tract, staging refers to the characteristics of the most advanced lesion. Note that the Lugano system does not include a stage III.

¹Any subtype of tumor extension (T1 to T4) or nodal (N0 to N3) or metastatic (M0 to M2) involvement;

²Non-contiguous gastrointestinal involvement refers to the presence of lymphoma in more than one gastrointestinal site with segments of discontinuity that are free of disease (such as the involvement of the stomach and rectum, with a free small intestine and bowel);

³Including the non-contiguous involvement of the peritoneum. References for the 4 staging systems are given in the main text.

Table 6 Tumor-node-metastasis staging system qualifiers

	Stage	Definition
Tumor	Tx	Extension of lymphoma not established
	T0	No evidence of primary lymphoma
Nodes	Nx	Nodal involvement not evaluated
	N0	No evidence of nodal involvement
Metastasis	Mx	Dissemination of lymphoma not evaluated
	M0	No evidence of lymphoma dissemination
Bone marrow	Bx	Bone marrow infiltration not evaluated
	B0	No evidence of bone marrow infiltration

Table 7 International prognostic index for aggressive B-cell lymphomas

Prognostic factor	Quantification
Advanced age	> 60 yr
Advanced stage	Ann arbor stages III or IV
High tumor burden and activity	Increased serum lactate dehydrogenase
Poor performance status	ECOG ≥ 2
Multifocal distribution	Two or more extranodal sites

The International Prognostic Index is calculated by adding 1 point for each adverse risk factor. ECOG: Eastern Cooperative Oncology Group performance status scale.

Table 8 Chemotherapy treatment options in American and European guidelines

Drug group	Drugs
Alkylators	Chlorambucil1
	Cyclophosphamide12
	Bendamustine12
Purine nucleoside analogues	Fludarabine12
	Cladribine1
Anthracyclines and anthracenediones	Doxorubicin2
	Mitoxantrone2
Vinca alkaloids	Vincristine2

Reflecting the lack of clear consensus, current guidelines propose different associations of these agents as monotherapy, combination chemotherapy, and combined immunochemotherapy with rituximab.

¹European Society for Medical Oncology 2013 guidelines;

²National Comprehensive Cancer Network 2011 guidelines.