Abstract 443

Background:

MYC translocations have been reported to have inferior outcome in aggressive non-Hodgkin lymphomas. Here we present MYC translocation prevalence and outcome from two cohorts of newly diagnosed diffuse large B-cell lymphoma (DLBCL) patients treated in the chemotherapy (C) and immunochemotherapy (IC) eras.

Methods:

Tissue microarrays were created from 302 newly diagnosed DLBCL patients evaluated at the Mayo Clinic with availabel paraffin tissue. 233 DLBCL patients first diagnosed from March 1986-July 2001 were retrospectively identified based on a diagnosis of DLBCL and treatment with anthracycline-based chemotherapy. 69 DLBCL patients diagnosed from March 2002-October 2005 and treated with immunochemotherapy were prospectively enrolled in the University of Iowa / Mayo Clinic Lymphoma SPORE Molecular Epidemiology Resource. Central pathology review was performed on all samples to confirm the diagnosis of DLBCL. Interphase FISH was performed using a breakapart strategy for MYC and BCL6 gene regions and a dual fusion strategy for t(14;18)(IGH&/BCL2).

Results:

Chemotherapy (C) era patients were primarily treated with CHOP (88%); immunochemotherapy (IC) era patients were all treated with an R-CHOP based regimen. The median age at diagnosis was 65 years (range, 22-92) for C patients and 65 years (range, 20-82) for IC patients. Median follow-up for C patients was 11.3 years (range, 2.7-21.3) with 145 (62%) deaths; for IC patients, the median follow-up was 5.0 years (range, 2.1-6.4) with 17 deaths (25%). FISH was successful in 195 of 302 patients (65%). MYC translocations were identified in 6 of 141 C patients (4%) and 3 of 54 IC patients (6%). MYC translocations were associated with inferior overall survival in the C patients (p=0.001), the IC patients (p=0.04), and in the combined group (p≤0.001). Median survival of patients with MYC translocations was 19 months and 16 months for C and IC respectively, compared to 112 months (C) and unreached (IC) for DLBCL patients without MYC translocations. 4 of the 9 MYC translocation patients had a double hit (2 with both MYC and BCL2 translocations and 2 with translocations of MYC, BCL2, and BCL6). Associations of MYC and outcome remained significant in all patients after adjusting for treatment and IPI (p<0.05).

Conclusions:

MYC translocations are present in approximately 5% of DLBCL patients and are associated with poor outcome in patients treated with C or IC. New treatment approaches are needed for DLBCL patients with MYC translocations.

Chemotherapy Treated Patients (C)
Immunochemotherapy Treated Patients (IC)
All Patients
N (%)OS Hazard Ratio (95% CI)N (%)OS Hazard Ratio (95% CI)N (%)OS Hazard Ratio (95% CI)
No MYC translocation 135 (96%) 1.00 (reference) 51 (94%) 1.00 (reference) 186 (95%) 1.00 (reference) 
MYC translocation 6 (4%) 3.74 (1.61, 8.69) 3 (6%) 4.42 (0.95, 20.5) 9 (5%) 3.67 (1.76, 7.66) 
Chemotherapy Treated Patients (C)
Immunochemotherapy Treated Patients (IC)
All Patients
N (%)OS Hazard Ratio (95% CI)N (%)OS Hazard Ratio (95% CI)N (%)OS Hazard Ratio (95% CI)
No MYC translocation 135 (96%) 1.00 (reference) 51 (94%) 1.00 (reference) 186 (95%) 1.00 (reference) 
MYC translocation 6 (4%) 3.74 (1.61, 8.69) 3 (6%) 4.42 (0.95, 20.5) 9 (5%) 3.67 (1.76, 7.66) 
Disclosures:

No relevant conflicts of interest to declare.

Author notes

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Asterisk with author names denotes non-ASH members.

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