Impact of Chromosomal Abnormalities in the Recipients of Allogeneic Hematopoietic Stem Cell Transplantation with Adult T-Cell Leukemia / Lymphoma

Adult T-cell leukemia/lymphoma (ATLL), which is a human T-lymphotropic virus thpe I (HTLV-1) related hematological malignancy, is known as a poorly prognostic disease even with the intensive chemotherapeutic regimens. It is known that ATLL cells normally have chromosomal abnormalities. These abnormalities were various types of numerical aberrations and complex structural abnormalities (Kamada N et al. Cancer Res. 1992). So far only one report showed that the impact of chromosome abnormalities for survival outcomes in ATLL patients who received chemotherapies (Itoyama T et al. Blood 2001). The report suggested that complex karyotype (more than 6 break points), abnormalities of 1p, 1q, 3q, 14q, and 17q was the poorly prognostic factors. Here we have analyzed the impact of chromosomal abnormalities in 26 ATLL patients who received allo-HSCT.

Seventy-two ATLL patients consecutively underwent allo-HSCT from June 2006 to March 2014 at our center. Karyotype study was performed with G-banding stain. Since patients’ chromosomal study showed normal karyotype and/or bad proliferation or no information about chromosomal study, 46 of 72 patients were excluded from this study. Rest of 26 patients (13 male, 13 female) were eligible for this study.

The median age of patients was 54 years (34-65). All patients, except one lymphoma type patient, were diagnosed as acute type ATLL. Thirteen of 26 patients were performed unrelated BMT, 8 sibling-BMT, 2 sibling PBSCT and 3 UCB. Eighteen patients used MAC regimens and 8 RIC regimens. With respect to disease status at allo-HSCT, 6 patients were in CR, and 20 non-CR. Specimen materials were from 11 PB, 8 BM, 6 lymph node and 1 pleural effusion, respectively. The median number of numerally chromosomal abnormalities was 2 (0-10), and the median number of structural abnormality was 4 (0-12), respectively. The majorities of numeral abnormalities were defects of sex chromosomes (31%), -14 (24%) and -10 (17%), etc. Structurally, more than 6 break points of the chromosomal abnormalities were seen in 11 patients. Majorities of structural abnormalities were abnormalities of 14q (41%), 1q (28%), 4q (28%) and 7q (28%), etc. The median study observation days was 173 days (12-2895) and an overall survival (OS) was 40.7%. Statistically, no impacts were seen in chromosomal abnormality of more than 6 break points (HR:1.839, 95%CI: 0.67-5.04, P=0.237), abnormalities of 1q (HR: 2.035, 95%CI: 0.718-5.77, P=0.182), 3q (HR: 1.1, 95%CI: 0.312-3.88, P=0.882), 14q (HR: 1.516, 95%CI: 0.565-4.07, P=0.409) and any other chromosomal abnormalities with OS. Also, no statistical impacts were seen in these chromosomal abnormalities with relapse rate and non-relapse mortality after allo-HSCT, respectively.

Although relatively a small number study, the results newly showed that allo-HSCT would have a potential to overcome the poor prognostic risks in chromosomal abnormalities.