Primary Gastric T-Cell Lymphoma: Clinicopathologic Features and Treatment Outcome.

Primary gastric lymphoma is the most frequent type of extranodal malignant lymphoma. The large majority of cases are of B-cell lineage, while primary gastric T-cell lymphomas are exceedingly rare and least well characterized malignancy and the clinical features have been described only in a few case reports. In this study, we conducted a retrospective analysis to investigate the natural history and the clinical outcome after treatment. Between 1990 and 2004, 444 patients with primary gastric lymphoma had been diagnosed at four institutes. Among these 444 patients, 17 patients (3.8%) were identified as primary gastric lymphoma with T-cell immunophenotype. The pathologic review was performed by two experienced hematopathologist to confirm T-cell lymphoma with typical immunohistochemical features including CD3. All of the patients were staged according to the Mushoff system. Among these 17 gastirc T-cell lymphoma patients, 14 patients were treated with combination chemotherapy including CHOP with or without radiotherapy. The two patients were treated with high-dose chemotherapy with autologous peripheral hematopoietic stem cell transplantation. The median age of the 13 male and 4 female patients was 49 years (range 22–76 years). The pathologic subtypes of these patients with T-cell immunophenotype were as follows; precursor T-lymphoblastic lymphoma in 2 patients, peripheral T-cell lymphoma, unspecified in 6 patients, NK/T cell lymphoma in 3 patients, and T-cell others in 5 patients. The many of the patients showed poor performance status (PS), and high LDH level (65%). 12 patients (71%) showed stage III or IV diseases, and 9 patients (53%) showed high or high-risk according to the International Prognostic Index (IPI). A response to treatment was observed in 8 patients (47%), with 6 Complete Response (CR) and 2 Partial Response (PR). The median Progression-Free Survival (PFS) and Overall Survival (OS) were only 5 months (95% C.I.; 4–6 months), and 14 months (95% C.I.; 0–189 months). 5 patients of these 17 patients (29%) presented only in stomach and regional lymph nodes. The patients with localized gastric T-cell lymphoma showed good therapeutic outcome (median PFS; 53 months, median OS; 123 months, p =0.024 by log-rank test). Other clinical factors including PS, age, and LDH did not show clinical significance in this series. Although our series had limitation to interpret due to small population, this study showed that the incidence of this subtype of T-cell gastric lymphoma was very rare, and poor prognosis, like as other T-cell lymphoma. However, about 30% of the patients had localized diseases limited to gastric area and regional lymph nodes with relative good prognosis. New therapeutic strategies need to improve the outcome of patients with gastric T-cell lymphoma.