Abstract 900P
Background
Plasmablastic lymphoma (PBL) is a rare, aggressive subtype of non-Hodgkin’s lymphoma. Effective treatment options are lacking due to the rarity of the disease.
Methods
We conducted a systematic review of the PubMed and our internal records to retrieve cases with PBL diagnosis with evaluable treatment outcomes. Aggressive chemotherapy was defined as more intense regimens than CHOP.
Results
We compiled a metadataset of 173 patients (pts). The median age at diagnosis was 48.5 years. 75% were male, and 93% had extranodal involvement. The Ann Arbor stages III/IV were accounted for 47% of the cohort. The EBV, HIV, and HHV-8 were positive in 72%, 50%, and 10% of pts, respectively. Immunophenotyping and genetic analysis showed positive CD38, CD138, EBER, MYC rearrangement and CD20 in 94%, 89%, 69%, 67%, and 8% of pts, respectively. Out of 138 pts with known response status after first-line chemotherapy, 63 (45%) pts achieved CR with a 2-year relapse-free survival of 71.6%. Sixty-nine (50%) pts received first-line CHOP. There was no significant difference in the objective response rate among the two most commonly used regimens CHOP and DA-EPOCH (69% vs. 79%, p=0.4). The subset of 7 pts receiving bortezomib-EPOCH achieved higher CR and less relapse rate compared to 19 pts received EPOCH only (100% vs. 47% and 0% vs. 40%, p=0.05). The 9 pts who received lenalidomide/thalidomide-based regimens achieved CR with only 2 reported relapses. The median follow-up was 9 months, and the 2-year overall survival (OS) was 47.4%. A univariate analysis identified factors associated with worse OS, including stage III-IV (Hazard ratio (HR): 2.82, p<0.001), HHV-8 positive (HR: 3.30, p=0.01), bone marrow (HR: 1.07, p=0.035) and cardiorespiratory involvement (HR: 2.26, p=0.015). Meanwhile, EBER-positive (HR: 0.31, p<0.001) and involvement of head & neck (HR: 0.44, p=0.009) were associated with better OS. Multivariate analysis showed that aggressive chemotherapy was significantly associated with better OS (HR: 0.22, p=0.016).
Conclusions
PBL pts with high-risk features, such as advanced stage, HHV-8 positive, bone marrow, and cardiorespiratory involvement, require more aggressive chemotherapy. Bortezomib and lenalidomide are promising add-on agents.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.