Prognostic value of chromosomal translocations in small-bowel diffuse large B-cell lymphoma

Aims: The objective of this study was to investigate the incidence and clinical significance of lymphoma-associated chromosomal translocations, particularly those involving the immunoglobulin heavy chain gene (IGH) locus, in patients with small-bowel diffuse large B-cell lymphoma (DLBCL). Methods and results: Translocations involving IGH, bcl-6, MYC and bcl-2 were investigated with interphase fluorescence in-situ hybridization on paraffin-embedded tissues in 35 patients with primary small-bowel DLBCL, and the overall survival (OS) and progression-free survival (PFS) rates were evaluated with the Kaplan-Meier method. Translocations involving IGH, bcl-6, MYC and bcl-2 were detected in 23 (70%), 12 (36%), eight (24%) and six (18%) of 33 cases, respectively. The patients with IGH translocations showed less frequent relapse or progression of lymphoma (17%) than those without (60%, P = 0.034). Univariate analyses demonstrated that young age, a low international prognostic index, translocations involving IGH, extra copies of MALT1/bcl-2 and bcl-6 immunoexpression were significantly associated with better OS and PFS. Cox multivariate analysis revealed translocations involving IGH to constitute an independent prognostic factor for better PFS, but not better OS. Conclusions: Translocations involving IGH are frequent in cases of small-bowel DLBCL. These translocations may be predictive of a favourable clinical course.