Plasmablastic Lymphoma: Experience from a Single Referral Center in Mexico

Plasmablastic lymphoma (PBL) is a rare subtype of lymphoma, with high proliferation rate and poor prognosis. Pathologically, tumor cells express plasma cell-associated antigens. PBL cells are positive for CD79a, IRF4, MUM1, BLIMP1, CD38 and CD138, while they are typically negative for B markers CD19, CD20. Approximately 70% of plasmablastic lymphomas show Epstein Barr Virus expression particularly in HIV-cases. Prognosis is poor, with Overall Survival (OS) less than 12 months in most series. There is no established standard treatment for PBL due to its low frequency and clinical variability. To date, there is limited data in patients with plasmablastic lymphoma in the Mexican population. The objective of this study is to analyze the clinical and biochemical characteristics that influence overall survival and progression-free survival in PBL patients; we divided the patients in two groups based on the clinical stage of the disease.

Our group conducted a retrospective analysis of all cases of plasmablastic lymphoma treated at our institution Hospital General de México “Dr. Eduardo Liceaga” over the past eight years. Complete clinical records of patients over 18 years old who had confirmed de novo plasmablastic lymphoma by biopsy from tissue were included.The primary objective of this study was to evaluate the overall survival at one year of follow-up between limited (I-II) and advanced (III-IV) clinical stages. Secondary objectives were to describe the demographic, clinical, and biochemical characteristics of the population received in our institution and evaluate the complete response and relapse rates.

This study reviewed our Lymphoma database and identified 15 cases of plasmablastic lymphoma diagnosed over the past eight years. Out of the 15 patients, 12 were male. The median age of the patients was 36 years, with an age range of 21 to 69 years. Eight of 15 patients (53.3%) had advanced clinical stage at diagnosis (Stage III-IV), while the remaining patients have limited clinical stage (I-II) (n=7). Only three patients ranked the International Prognostic Index (IPI) at 3 or higher. Moreover, 12 patients out of 15 were HIV-positive and only five had a positive viral load at diagnosis and all were in treatment. Six patients presented secondary comorbidity at diagnosis, 13 patients received EPOCH. Toxicity was measured in eight patients (53.3%), the most common adverse effect was infections Only four patients out of 15 received radiotherapy. We found thah only five patients had a complete response. The median follow-up period was 5.77 months (range 1.4 - 12 months). The one-year follow-up showed survivorship of 33.3% of the population (n=5). No statistical significance was found when comparing overall survival at one-year follow-up between limited and advanced clinical stages at diagnosis (Log-Rank: 0.144).

We conducted a single center retrospective analysis of patients with plasmablastic lymphoma to evaluate clinical characteristics related with survival and outcomes for this population. We found that most patients were male as previously described, with median age of 36 years, which represents a younger population regarding information published in other series of patients. Our analysis found out that the most frequent extranodal site involved was rectal mucosa. 53% of our patients had advanced disease at diagnosis.We found no better outcomes in HIV-related patients. In our population patients who received radiation did not have better survival outcomes. At one year follow-up, the overall survival was 33%, confirming the poor prognosis of this population despite treatment.

Most of the data reported in this study is like the previous. The poor prognosis of this type of lymphoma, and worse outcomes in patients with HIV that are found in this study is consistent with reports from all over the world, but in developing countries like ours the epidemiology is very scarce, and thus it is important to continue these reports.

No relevant conflicts of interest to declare.