ISHL10 Abstract P035

IGH-mediated translocations, recurrent in classic Hodgkin lymphoma, frequently correlate with an aggressive behavior

Cytogenetic features of classic Hodgkin lymphoma (cHL) remain largely unknown. Interphase FISH (iFISH) studies, however, suggest that IGH-mediated t(14q32) are recurrent in cHL (PMID: 17079453, 18940474). Recently, we have identified t(14;18)(q32;q21)/IGH-BCL2 and inv(14)(q11q32)/IGH-CEPBE in two patients with nodular sclerosis HL (NSHL) analyzed at time of relapse. To identify additional cHL cases with t(14q32/IGH) and check whether these rearrangements correlate with clinical outcome, we screened by iFISH: (i) 46 relapsed cHL, (ii) 40 cHL with a long-term remission, and (iii) 60 prospective cases. Altogether, IGH rearrangements were detected in 28 patients, including 17 representing the former group (35.4%), 4 cases representing the second group (10%) and 7 prospective cases (11.6%). LSI IGH FISH pattern suggested a reciprocal t(14q32/IGH) in 20 cases, nonreciprocal t(14q32/IGH) in 4 cases, inv(14q32/IGH) or ins(14q32/IGH) in 3 cases and interstitial del(14q32/IGH) in one case. Twenty six cases were further analyzed by iFISH with break-apart (BA) assays for BCL2, BCL3, BCL6 and MYC. In 3 cases with likely inv(14)/ins(14), CEPBE BA was applied. Altogether, we have identified the IGH-BCL2 rearrangement in two cases, including the index case with t(14;18), and the IGH-CEPBE rearrangement in the case with inv(14). All the remaining cases showed a non-rearranged status of the examined loci. The majority of patients (18/28) with t(14q32/IGH) were diagnosed with NSHL. There were 18 male and 10 female patients in age ranging from 18 to 91 years (mean 50). Patients presented with both early (10/26) and advanced (16/26) stage (two not staged). All were treated with chemotherapy with or without radiotherapy, except for two patients who were subjected to a palliative treatment. After induction therapy, complete and partial remission was achieved in 17 and 5 patients, respectively. Thirteen patients are alive (11 without disease and 2 with disease); 13 patients died, including 11 whose death was related with a disease, and two are lost for follow up. In summary, we confirmed that chromosomal aberrations involving 14q32/IGH occur recurrently in cHL. These rearrangements rarely target BCL2 and CEPBE, and do not affect BCL3, BCL6 and MYC. Interestingly, 17 out of 21 (81% ) patients with t(14q32/IGH) showed an aggressive behavior. Our study allows a new insight into the pathogenesis of cHL and might help in further stratification of cHL patients.

Authors

  • I. Wlodarska
  • D. Dierickx
  • U. Pluys
  • K. Doms
  • C. Graux
  • A. Van Hoof
  • P. Vandenberghe
  • L. Michaux
  • T. Tousseyn