MYC+ diffuse large B-cell lymphoma is not salvaged by classical R-ICE or R-DHAP followed by BEAM plus autologous stem cell transplantation.

ABSTRACT

Approximately 5-10% of diffuse large B-cell lymphomas (DLBCL) harbor a 8q24/MYC rearrangement (MYC(+)). We determined the prognostic significance of MYC rearrangement in patients with relapsed/refractory DLBCL prospectively treated by R-ICE or R-DHAP followed by high-dose therapy and autologous stem cell transplantation. Twenty-eight (17%) of the 161 patients analyzed presented a MYC(+) rearrangement, targeted as either simple hit (25%) or complex hits (n=75%) including MYC/BCL2, MYC/BCL6, and MYC/BCL2/BCL6. Results were statistically highly concordant in matched primary and relapsed biopsies (n = 45). Compared to the MYC(-) DLBCL patients, the MYC(+) DLBCL patients presented with a more elevated lactico-deshydrogenase level (P = .0006) and a more advanced age adjusted international prognostic index (P = .0039). The 4-year PFS and OS were significantly lower in the MYC(+) DLBCL patients than those in the MYC(-) DLBCL patients, with rates of 18% vs 42% (P = .0322), and of 29% vs 62% (P = .0113), respectively. Type of treatment, R-DHAP or R-ICE, had no impact on survivals, with 4-year PFS rates of 17% vs 19% and 4-year OS rates of 26% vs 31%. In conclusion, MYC rearrangement is an early event in DLBCL. MYC(+) DLBCL patients have a significant inferior prognosis than MYC(-) DLBCL patients. Their outcome was not influenced by the proposed salvage therapy.