Plasmablastic Lymphoma Among HIV-Positive Patients: A Curable Entity? Results of a Single Centre's Experience
Authors: Cattaneo Chiara , Re Alessandro , Peli Annalisa , Casari Salvatore , Fogazzi Stefano , Antoniazzi Francesca , Pagani Chiara , Schieppati Francesca , Scalzini Alfredo , Castelli Francesco , Rossi Giuseppe 
Published: October 2019

Abstract
Abstract 3640

Background.
Recently published data concerning Plasmablastic Lymhoma (PBL) developing in HIV-positive (HIV-pos) patients (pts) confirm the adverse prognosis both in terms of overall survival (OS) and progression free survival (PFS) of this rare entity (Castillo et al, Cancer 2012 doi: 10.1002/cncr.27551), even using an intensive treatment approach.

Aims.
To verify this clinical behaviour, we evaluated clinical characteristics, response to treatment and outcome of PBL HIV-pos pts admitted to our Institution.

Patients and Methods.
Data concerning pts affected by PBL were extracted from the database in which, since 1985, all new consecutive cases of HIV-pos lymphoma are prospectively registered. All cases were histologically reviewed and in those diagnosed before 1997 the diagnosis was confirmed according to criteria indicated by Delecluse et al (Blood 1997; 89:1413).

Results.
During 27 years of observation, 18 PBL HIV-pos pts were registered, 4 in the pre-HAART (before 1997) and 14 in the post HAART (after 1997) era. Median age was 36.5y (range 26–54), male/female ratio 15/3. Median time from HIV-positivity detection to PBL was 2.8y (0–24.9). Median CD4 count at PBL diagnosis was 248/mcL (13–727) and 7/18 pts (38.9%) had a CD4 count <200/mcL. B-symptoms were present in 29.4% of pts and advanced stage (III-IV) in 82.5% of pts. Oral cavity involvement was observed in 47% of pts and extranodal involvement in 88%. An intermediate-high aaIPI was observed in 11/18 pts (61.1%). Two pts were not evaluable because of early death and refusal of treatment (1 pt each). Sixteen out of 18 pts were treated with CHOP or CHOP-like regimen; three received autologous stem cell transplantation (ASCT) as consolidation of first-line therapy and 2 as salvage therapy. Fifteen of 16 pts (93%) achieved a complete remission (CR) and 1 showed disease progression (PD). Three pts relapsed, at +5, +6 and +21 months respectively. After a median follow-up of 32 months (range 4–184), OS and PFS at 3y were 70.9%±12.6%SE and 56%±14.1%SE respectively. PFS was influenced neither by aaIPI (at 3y: aaIPI 0–1: 51.5%±20.4% vs aaIPI 2–3: 67.5%±15.5) nor by CD4 count (at 3y: CD4 <200/mcL: 50%±20.4% vs CD4>200/mcL: 60.6%±19.8%), whereas a trend for a better OS in pts with low aaIPI and CD4 count >200/mcL was observed (at 3y: aaIPI 0–1: 83.3%±15.2% vs aaIPI 2–3: 59.1%±19.8%, p=0.22, and CD4 <200/mcL: 50%±20.4% vs CD4>200/mcL: 90.9%±8.7%, p=0.17). All of the 4 pts diagnosed in the pre-HAART era underwent chemotherapy; 3 pts died (2 of PBL and 1 of AIDS). Twelve of the 14 pts diagnosed in the post-HAART era received curative treatment; all of them achieved CR and only 1 died of an event unrelated to lymphoma or HIV (car crash). When comparing pre and post-HAART era, OS at 3y was 25%±21.6% and 92.3%±7.4% respectively (p=0.13); PFS at 3y was 25%±21.6% and 69.9%±15.4% (p=0.38). No relapses after 3y were observed.

Conclusions.
Our data show that, in spite of its clinical aggressiveness, PBL seems to be curable in a high proportion of pts. A low aaIPI, and a higher CD4 count as well as the use of HAART positively influenced survival, whereas PFS was similar in all the settings. Discrepancies with data of the literature may be related to the shorter interval between HIV-positivity and PBL diagnosis in comparison with the series reported by Castillo et al, and to the more aggressive treatment approach including ASCT used in this series. Further studies, with a larger number of pts, are warranted in order to confirm these observations.

Disclosures:
No relevant conflicts of interest to declare.