Purpose: To identify DEL amongst veteran patients with diffuse large B cell lymphoma (DLBCL) and its outcome.
Background: Molecular profile determines prognosis in DLBCL. Activated B-cell (ABC), a subtype of DLBCL, is associated with poor outcome compared to germinal center Bcell (GCB). Poor response to standard chemotherapy is seen with double-hit lymphomas as detected by FISH (5% -10% of DLBCL) and DELs that express both MYC and BCL-2 as detected by immunohistochemistry (IHC) (cutoffs—30% MYC, 40% BCL-2), with a median overall survival of <12 months.
Methods: Sixty-nine DLBCL patients diagnosed at DC VAMC from 1/1996-4/2016 were identified utilizing cancer registry. IHC stains were reviewed for CD3, CD10, CD20, BCL-2, BCL-6, C-MYC, MUM-1, MIB1, and p53. DLBCL were sub-classified as GCB and ABC based on CD10, BCL6 and MUM1 stains. Demographic data, diagnosis, treatment and outcome in terms of relapse and death are analyzed and will be presented at the meeting.
Results: Of the 69 DLBCL cases, only 37 met inclusion criteria; 32 were excluded due to unavailable blocks (20, mostly sent to outside institutions), tissue exhaustion with incomplete IHC data (6), T-cell rich B cell lymphoma (5) and pending (1). 20 cases are GCB and 17 ABC. All cases are CD20 positive with high mib1. MYC is positive in 17 cases (46%) and 15 of them double positive for BCL-2 (40%).
Implications/Future Directions: DLBCL veterans at the DC VAMC have a high percentage of double expressors when compared to the literature. It will be important to examine clinical data, treatment, and outcome to develop better treatment guidelines for double-expressor DLBCL. Future studies are in plan to compare double hit lymphomas to double expressors.
