Introduction:

Diffuse large B cell lymphoma is a heterogenous disease with prognosis known to vary based on histological changes including immunohistochemistry and gene rearrangements by florescence in situ hybridisation (FISH). Both immunohistochemical overexpression as well as gene rearrangements in MYC, BCL2 and BCL6 are thought to contribute to poor prognosis. The benefit of high dose chemotherapy is unclear for those with high grade B cell lymphoma with double hit status (DHL) by FISH , double expressor status (DEL) or gain of MYC/BCL2. The purpose of this study was to retrospectively analyse the effect of escalated chemotherapy in this population over a 5 year period.

Methods:

All patients with DLBCL treated between 2012-2017 were screened retrospectively for inclusion in the study based on immunohistochemistry and FISH at time of initial diagnosis. Immunohistochemistry was assessed on formalin fixed, paraffin embedded specimens with BCL2 and MYC considered positive at over 40% and 50% respectively. FISH was assessed using dual colour break apart probe.

Results:

135 patients were diagnosed with DLBCL of which 53 patients had immunohistochemistry and FISH at diagnosis confirming either, DEL or gain of MYC/BCL2 status. The mean age was 65 years and median follow up 21 months. The overall response rate in DH treated with DA-R-EPOCH was 57%. There were insufficient cases treated with R-CHOP for comparison. Overall response rates in DEL were 94% for DA-R-EPOCH and 93% for R-CHOP. Overall survival (OS) and disease free survival (DFS) in DHL was 6 months and 2 months respectively when treated with DA-R-EPOCH. There was no significant difference in OS or DFS in DEL treated with DA-R-EPOCH compared with R-CHOP (OS: 42 months vs 38 months respectively (p=0.962), DFS 36 months vs 30 months (p=0.931)). Gain of MYC/BCL2 did not affect OS (p= 0.539) or DFS (p=0.439) when comparing treatment regimen.

Conclusion: DA-R-EPOCH did not improve treatment response rates OS or DFS in patients with double expresser lymphoma or gain of MYC/BCL2. This study also confirms the previously reported poor outcomes associated with DHL

Disclosures

No relevant conflicts of interest to declare.

Author notes

*

Asterisk with author names denotes non-ASH members.

Sign in via your Institution