Primary Mediastinal Large B-Cell Lymphoma: A Single-Center Study of Clinicopathologic Characteristics

Abstract

Primary mediastinal large B-cell lymphoma (PMLBCL) is a subset of LBCL with unique clinicopathologic features. Some studies have raised the question of differences in biological features and clinical course among patients from different parts of the world. We conducted a retrospective clinicopathologic analysis of 24 patients with PMLBCL from a single center in Croatia. We also conducted the first investigation of the frequency of lymphotropic viruses human herpesvirus 6 (HHV-6) and HHV-8 in lymphoid lesions of this disease. The clinical characteristics of the patients were as expected, with high International Prognostic Index scores, elevated serum lactate dehydrogenase (LDH) levels, and bulky disease being adverse prognostic factors. Only 6 patients (25%) showed CD30 expression, and Bcl-6 protein expression was, in our series, prognostically favorable (P = .0401). One patient's tumor had detectable HHV-6 genome sequence, but no HHV-8 sequences were detected in any tumors. Two thirds of the patients received CHOP chemotherapy (cyclophosphamide, hydroxydaunomycin, vincristine, and prednisone) with a relatively low complete remission rate (43.8%; median follow-up, 33.8 months). This study confirmed the moderate preponderance among PMLBCL patients of young females with B symptoms and elevated LDH levels. The CHOP regimen proved effective as first-line therapy only in patients with limited disease. Therefore, other third-generation chemotherapy protocols may be considered for treatment, especially in patients with bulky and advanced disease.

Primary mediastinal large B-cell lymphoma (PMLBCL) in Chinese patients: clinical characteristics and prognostic factors

“…Our data showing that IPI and B symptoms were independently related to overall survival, agreed with previous reports [3,23]. We also showed for the first time that low serum albumin was a novel prognostic predictor of both OS and PFS in PMLBCL patients.…”

“…A number of studies have investigated different prognostic factors in PMLBCL with inconclusive results [9,10,22,23]. Our data showing that IPI and B symptoms were independently related to overall survival, agreed with previous reports [3,23].…”

Treatment of primary mediastinal large B cell lymphoma with an alternating chemotherapy regimen based on high-dose methotrexate

“…Based on the disappointing results with CHOP-like therapy [6][7][8], we started exploring dose intensification with a methotrexate-based alternating chemotherapy regimen in the late 1980s. Simultaneously, this regimen was also investigated in the treatment of another aggressive B cell disorder, namely, Burkitt's lymphoma/mature B-ALL.…”

“…Newer, gene array-based grouping of aggressive non-Hodgkin's lymphoma support the unique position with MLCL representing a defined subtype besides germinal center B cell-like (GCB) and activated B cell-like (ABC) diffuse large cell lymphoma [1,2,5]. The results of a cyclophosphamide, hydroxydaunorubicin (adriamycin), oncovin (vincristine), prednisone/prednisolone (CHOP)-based chemotherapy in European and non-European countries have been disappointing [6][7][8], making the treatment of this particular entity unique among the diffuse large B cell lymphomas (DLCL) irrespective of the individual (partially later developed) prognostic score. Dose intensification has always played a major role in the treatment of the disease and, in the prerituximab era, clearly improved the results of CHOP-based chemotherapy regimen [8,[9][10][11][12][13]].…”

Primary Mediastinal B-Cell Lymphoma: Novel Precision Therapies and Future Directions

“…Tumor cells are usually positive for nuclear transcription regulators such as BOB1, PU.1, OCT2, PAX5, BCL6, and IRF4. Bcl-6 protein has been detected in over 50% of tumor cells and is considered a favorable prognostic factor ( 21 , 22 ) ( Table 1 ).…”