Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Sep 21, 2021; 27(35): 5932-5945
Published online Sep 21, 2021. doi: 10.3748/wjg.v27.i35.5932
Primary gastric non-Hodgkin lymphomas: Recent advances regarding disease pathogenesis and treatment
Michael D Diamantidis, Maria Papaioannou, Evdoxia Hatjiharissi
Michael D Diamantidis, Department of Hematology, Thalassemia and Sickle Cell Disease Unit, General Hospital of Larissa, Larissa 41221, Thessaly, Greece
Maria Papaioannou, Evdoxia Hatjiharissi, Division of Hematology, First Department of Internal Medicine, AHEPA General Hospital, Aristotle University of Thessaloniki, Thessaloniki 54636, Greece
Author contributions: Diamantidis MD performed the literature review and wrote the manuscript; Hatjiharissi E wrote the manuscript, performed the literature review and corrected the manuscript; Papaioannou M wrote and corrected the manuscript.
Conflict-of-interest statement: All authors declare they have no conflicts of interest.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Evdoxia Hatjiharissi, MD, PhD, Consultant Hematologist, Division of Hematology, First Department of Internal Medicine, AHEPA General Hospital, Aristotle University of Thessaloniki, St. Kiriakidis 1, Thessaloniki 54636, Greece.
Received: March 22, 2021
Peer-review started: March 22, 2021
First decision: June 14, 2021
Revised: June 27, 2021
Accepted: August 30, 2021
Article in press: August 30, 2021
Published online: September 21, 2021

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.

Keywords: Primary gastric lymphoma, Extranodal non-Hodgkin’s lymphoma, Diffuse large B-cell lymphoma, Mucosa-associated lymphoid tissue, Immunochemotherapy, Rituximab-cyclophosphamide doxorubicin vincristine prednisone

Core Tip: A few small, heterogeneous, retrospective studies have attempted to determine the optimal treatment for gastric diffuse large B-cell lymphoma, investigating the role of chemotherapy +/- rituximab, surgery and radiation in patient outcomes. Our retrospective research suggests that a better outcome is observed for these patients after the introduction of immunochemotherapy (rituximab-cyclophosphamide doxorubicin vincristine prednisone). Because statistical analysis might differ among various studies, it is crucial to correctly define the terms freedom from progression and lymphoma-specific survival. The latter provides information on whether the patients died from lymphoma or from other causes.