Expression levels of apoptosis‐related proteins and Ki‐67 in nasal NK / T‐cell lymphoma

Abstract

Objectives: Nasal natural killer (NK)/T‐cell lymphoma is characterized by chemo‐resistance, angiodestruction, and aggressive tumor progression. Few studies exist on molecular characteristics of this disease entity. Methods: Expression levels of major apoptosis‐related proteins Bcl‐2, Bcl‐x, Mcl‐1, Bax, and a proliferative marker Ki‐67 were analyzed in 11 nasal NK/T‐cell lymphoma cases by immunohistochemical methods. Nine cases were of NK‐cell lineage and two cases were of T‐cell lineage. For comparison, 12 follicular lymphoma (FL) cases and 16 diffuse large B‐cell lymphoma (DLBCL) cases were also studied. Results and conclusions: Bax expression was low in all nasal NK‐cell lymphoma cases, which constitute the major population of nasal NK/T‐cell lymphoma. Bax expression in nasal NK‐cell lymphoma was similar to FL and significantly lower compared with DLBCL. Bcl‐2 expression was significantly lower in nasal NK/T‐cell lymphoma compared with that of FL and DLBCL. Bcl‐x expression was high in all three lymphomas. Two distinct Mcl‐1 expression groups existed for nasal NK/T‐cell lymphoma (6.2 ± 5.2% and 59.1 ± 12.3%, 95% CI). Ki‐67 expression was high in nasal NK/T‐cell lymphoma, and worse prognostic groups tended to express higher levels of Ki‐67. The results suggest a combination of impaired apoptosis and aggressive proliferation in nasal NK/T‐cell lymphoma, and may provide explanations for its poor prognosis.

A phase 2 study of methotrexate, etoposide, dexamethasone, and pegaspargase chemotherapy for newly diagnosed, relapsed, or refractory extranodal natural killer/T‐cell lymphoma, nasal type: a multicenter trial in Northwest China

“…Although patients whose tumors had ≥60% cells positive for Ki‐67 had a lower 3‐cycle rate of CR and lower 1‐year OS and PFS than did those whose tumors had <60% positive cells, the results were not statistically significant, and univariate analysis determined that a high Ki‐67 expression was not associated with a poor survival. This finding differs from those of previous studies 57, 58, 59, 60, 61, 62. Similarly, IPI score, disease stage, and expression of β2‐microglobulin and CD56, which have all been shown to be associated with survival for patients with nasal or extranasal NKTCL,59, 63, 64, 65, 66 were not associated with survival in our study.…”

Efficacy and Tolerance of Pegaspargase-Based Chemotherapy in Patients with Nasal-Type Extranodal NK/T-Cell Lymphoma: a Pilot Study

“…A novel prognostic index incorporating B symptoms, clinical stage, serum LDH level and regional lymph node involvement has been described (Lee et al, 2006). Ki-67 expression has been also reported as a prognostic factor in patients with ENKL (Kim et al, 2007;Yasuda et al, 2009;Huang et al, 2014;He et al, 2014). However, in this study, univariate analysis indicated that stage was the only prognostic indicator for PFS and OS.…”

Clinical implications of plasma Epstein-Barr virus DNA in early-stage extranodal nasal-type NK/T-cell lymphoma patients receiving primary radiotherapy

“…[22][23][24][38][39][40][41] Several small cohort of studies have demonstrated that a high EBV-DNA load is associated with advanced stage, poor clinical response, B-symptoms, and elevated LDH levels in NKTCL (supplemental Table 1, available on the Blood Web site; see the Supplemental Materials link at the top of the online article). [31][32][33][34][35] Our results confirmed that pretreatment EBV-DNA levels correlate with B-symptoms, elevated LDH levels, and an IPI score of 1-2 in early-stage NKTCL.…”