Clinicopathologic Comparison of Plasmablastic Lymphoma Patients According HIV-Status: Peruvian Experience

Background:Plasmablastic lymphoma (PBL) is an aggressive lymphoma associated mainly to HIV infection, although cases in immunocompetent patients are described as well. Objective:To describe the clinicopathologic features and determine the overall survival of lymphoma patients according human immunodeficiency virus (HIV) status in Peruvian patients. Methods:We reviewed the pathology databases of 2 cancer centers and a general hospital from Peru. Forty cases were documented between 2005 and 2020. Categorical variables were compared using Fisher's exact test. Survival curves were estimated using the Kaplan-Meier method and compared using the log-rank test. Statistical analysis was based on SPSS Program version 23. All cases were reviewed by two pathologists. Results:32 patients (80%) were HIV-positive. The median age for the whole cohort was 40 years (range, 22-86). The median age for HIV-positive and HIV-negative PBL patients were 37 years (range 22-67 years) and 57 years (range 27-86 years), respectively. The proportion of patients ≥60 years was lower in HIV-positive than in HIV-negative patients (8% and 37%, respectively; p= 0.046). 80% of patients in the whole cohort were female, and 84% and 62% in the HIV-positive and HIV-negative group, respectively. Extra-oral primary sites were the most frequent primary sites in both groups (66% and 88%, respectively). There were no statistically significant differences in Ann Arbor stage, Ki-67 expression, LDH levels, IPI scores, albumin levels, and neutrophil/lymphocyte ratio between HIV-positive and HIV-negative patients. All cases showed large lymphoid cells, of plasmablastic morphology with expression of at least one plasma cell marker (CD138, CD38, MUM1), CD45 positivity, variable expression of EMA, CD79 and CD30 and absence of expression of CD20, CD3, CD68 and LMP1; the proliferative index Ki67 varied between 60 and 90%. A small proportion of patients (18%) did not receive chemotherapy because of poor performance status or a personal decision. DA-EPOCH regimen was used in 52% and 25% of HIV+ and HIV- patients, respectively and CHOP/CHOEP regimen in 48 % and 75%, respectively. The overall response rate was 68% and 57% in HIV+ and HIV- patients with complete response (CR) in 32% and 14%, respectively. In the HIV-positive group, 66% of patients were antiretroviral therapy (ART)-naïve. The median progression-free survival (PFS) was 38 months and 7 months for HIV+ and HIV- patients, and the 1-year PFS was 74% and 0%, respectively. The median overall survival (OS) was 43 months (range 0.2-86.5) in HIV-positive patients and 10 months (range 0.5-19.0 months) in HIV-negative patients and the 1-year OS were 59% y 38%, respectively (p=0.27). Conclusions: PBL is a rare lymphoma, specially, if not related to HIV infection. In this study, 60 years or older was the only variable that showed significant difference. In our cohort, HIV-positive patients had better prognosis than HIV-negative PBL patients. Disclosures No relevant conflicts of interest to declare.