The expression of Ki-67 and Bcl-2 in Hodgkin's lymphoma: Correlation with the international prognostic score and bulky disease - A study by the Serbian Lymphoma Study Group (SLG)

The prognosis of Hodgkin's lymphoma has been improved over last 10 yr due to identification of prognostic parameters. These factors may predict the clinical outcome and therefore may have influence on the selection of appropriate treatment. In a cohort of 40 patients with Hodgkin's lymphoma of nodular sclerosis subtype, treated with ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine) regimen, we analyzed prognostic relevance of the expression of Ki-67 and Bcl-2 at diagnosis as well as other clinical parameters: International Prognostic Score, bulky disease, tissue eosinophilia, and high erythrocyte sedimentation rate. Significance was tested according to response rate and overall survival. Patients with a high proliferative fraction (Ki-67 > 50%) had worse overall survival compared with those with low proliferation, 56% vs 91 %. There was a correlation between Ki-67 positivity and the achievement of complete remission. Cox's multivariate model revealed that Ki-67 positivity at threshold of 50% was a significant independent prognostic factor. The Bcl-2 expression in less than 50% of tumor cells was detected in 65.5% of patients, and in a majority of cases it was associated with complete remission. Patients with high IPS had more progressive disease and shorter survival. Bulky disease, tissue eosinophilia, and high erythrocyte sedimentation rate had no significant influence on complete remission and survival. However, there was a marked divergence in survival curves after 4 yr follow-up for each of these parameters. Patients with high Ki-67, IPS > 3, bulky disease, tissue eosinophilia, and high sedimentation rate are at a higher risk of treatment failure and relapse and therefore might be eligible for other aggressive therapeutic approach.