Different prognostic factors for survival in acute and lymphomatous adult T-cell leukemia/lymphoma

Abstract

Introduction: Adult T-cell leukemia/lymphoma (ATLL) is a clinically aggressive and heterogeneous entity; hence it is likely that different variants of ATLL have different prognostic factors. Methods: 95 patients with ATLL seen at our institution between 1987 and 2008 were included. Clinical data were compared, according to ATLL variant, using the Mann–Whitney and the Chi-square tests for continuous and categorical variables, respectively. Kaplan–Meier estimates compared using the log-rank test and Cox proportional-hazard test were used for the univariate and multivariate analysis, respectively. Results: Median age was 61 years with male-to-female ratio of 1.07:1. Patients with acute ATLL were more likely to present with bone marrow, liver and spleen involvement, higher β2-microglobulin and lower albumin levels. Poor performance status, high IPI score, presence of B symptoms, high LDH and low albumin levels were associated with a worse survival in lymphomatous ATLL. High LDH, high β2-microglobulin and high PIT score were associated with worse survival in acute ATLL. In the multivariate analysis, low albumin level and presence of B symptoms were independent factors for worse survival in lymphomatous ATLL, and high β2-microglobulin level was independent factor for worse survival in acute ATLL. Conclusions: Aggressive ATLL variants have a distinct, almost mutually exclusive profile of prognostic factors.

Introduction

ATLL is a clinically heterogeneous disease with several well-described clinical variants, from which the acute (leukemic) and the lymphomatous subtypes are the most aggressive, characterized by a rapidly progressing disease and short survival [1]. The chronic and smoldering subtypes are more indolent; however, they can progress into more aggressive phases of disease. More recently, cutaneous variants of ATLL have been described, also characterized by a more indolent clinical course [2].

The human T-lymphotropic virus type-1 (HTLV-1) is the pathogenic agent associated with the development of adult T-cell lymphoma/leukemia (ATLL), among other diseases [3]. HTLV-1 is a RNA retrovirus, endemic in Southwestern Japan, the Middle East, North Africa, the Caribbean and South America. Peru is an endemic area for HTLV-1 infection and it is estimated that 1–3% of the healthy adult population are HTLV-1 carriers [4], [5]. However, the Peruvian experience in patients with ATLL has not been previously published.

Several clinical factors have been associated with prognosis in patients with ATLL [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18]. Older studies have identified several clinical factors, such as LDH levels and performance status [12], [19], leukocyte count and calcium levels [11], [19], among others. More recently, the International Prognostic Index (IPI) score has shown to be of prognostic value in aggressive subtypes of ATLL [13]. However, given the clinical and molecular differences between acute and lymphomatous subtypes of ATLL, it is likely that the clinical factors associated with survival would also be different. Shimamoto and colleagues evaluated this hypothesis in a small cohort of patients with ATLL and found almost exclusive sets of prognostic factors for each subtype [11]. In this study, our main objective was to evaluate the differences in prognostic factors between acute and lymphomatous variants of ATLL.