Abstract
Lymphoepithelioma-like gastric cancer (LELGC) is a rare subtype of gastric carcinoma associated with Epstein-Barr virus infection. Although it can manifest as a large tumor mass, it has been reported to have a more favorable prognosis compared to other subtypes. Most of the available evidence comes from Asian countries, with few reports in Latin America.
This article describes three cases of patients with a histopathological diagnosis of CGLEL, all confirmed by in situ hybridization for Epstein-Barr coding RNA. Of these, two patients presented with relapse and disease progression, which led to the evaluation of PD-L1 expression and the initiation of immunotherapy treatment, with favorable clinical responses. The third patient is currently disease-free. Although CGLEL can mimic other subtypes of gastric carcinoma in imaging studies, histopathological findings are essential for establishing an accurate differential diagnosis and guiding the appropriate therapeutic approach.
Introduction
Lymphoepithelioma-like gastric cancer (LELGC) is a rare subtype of gastric carcinoma, first described in 1976 by Watanabe et al. as a gastric carcinoma with lymphoid stroma. It is most commonly located in the upper and middle portions of the stomach, with a higher prevalence in men[^3,^4]. In general, it is considered a carcinoma with a good prognosis, partly due to a significant proportion of diagnoses made before metastatic involvement; however, it remains a relatively rare neoplasm.
A retrospective real-world study conducted between 2005 and 2019 in five cancer centers in China included 770 patients with lymphoepithelioma-like carcinomas (LELC), of whom 16 cases were identified as having a primary gastric tumor, corresponding to a prevalence of 2.1%. In contrast, information on this entity in Latin America is scarce.
Several types of carcinomas have been associated with infection by Epstein-Barr virus (EBV), a lymphotropic virus, including undifferentiated nasopharyngeal carcinoma, Hodgkin’s lymphoma, and Burkitt’s lymphoma. In the case of gastric carcinoma, an association with EBV has been identified in 7.0–10.0% of cases, depending on the histological type, with a higher frequency in tumors with microsatellite instability and lymphocyte-rich phenotypes. Up to 80.0% of cases of CGLEL are associated with EBV infection, with a higher frequency observed in men, in tumors with proximal localization and diffuse histology, although the latter association is not conclusive. However, cases of EBV-negative CGLEL with microsatellite instability have also been documented.
Radiologically, this neoplasm may appear on CT scans as focal thickening of the mucosa, marked thickening of the gastric wall evident with contrast, or as a bulky mass.
No specific guidelines have been designed for the treatment of this subtype, so it is generally managed in a similar way to conventional gastric adenocarcinoma, with D2 lymphadenectomy being the surgical strategy of choice.
Below are three cases of patients with CGLEL, two of whom had a decline after systemic treatment; these patients were selected by convenience sampling from among those attending the Clinical Oncology Unit of the National Cancer Institute (INC) in Bogotá, Colombia.
In both cases, PD-L1 (programmed death-ligand 1) expression was evaluated, and a favorable clinical response to immunotherapy was observed.
This report is particularly relevant given the limited evidence in the Latin American population and the limited information on the role of immune biomarkers in this type of carcinoma. To the authors’ knowledge, this is the first regional report documenting PD-L1 positivity and its association with a positive clinical response to immunotherapy in CGLEL. These findings could have important therapeutic implications and encourage future research in this emerging field.
Daniela Patiño-Hernández, Diego-Felipe Ballén, Jorge Mesa-López de Mesa, Rafael Parra-Medina
1 Resident in Clinical Oncology Specialization, Pontificia Universidad Javeriana – Instituto Nacional de CancerologÃa, Bogotá, D. C., Colombia.
2 Internal Medicine Service, San Ignacio University Hospital, Bogotá, D. C., Colombia.
3 Clinical Oncology Unit, National Cancer Institute, Bogotá, D. C., Colombia.
4 Clinical Oncology Service, San Ignacio University Hospital, Bogotá, D. C., Colombia.
5 Faculty of Medicine, Pontificia Universidad Javeriana, Bogotá, D.C., Colombia. 6 Oncology Pathology Group, National Cancer Institute, Bogotá, D.C., Colombia.
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https://www.revistacancercol.org/index.php/cancer/article/view/1103/1094
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