Acquired chromosome 11q deletion involving the ataxia teleangiectasia locus in B-cell non-Hodgkin's lymphoma: correlation with clinicobiologic features

Abstract

Purpose: To study the clinicobiologic significance of acquired 11q deletions involving the ataxia teleangiectasia locus (ATM+/-) in B-cell non-Hodgkin's lymphomas (NHL).

Patients and methods: Fifty-three indolent lymphomas and 82 aggressive lymphomas were studied by conventional cytogenetic analysis and by fluorescence in situ hybridization using an 11q22-23 probe recognizing ATM sequences. Pertinent clinical data were collected.

Results: A hemizygous ATM deletion was seen in 44% to 88% of the interphase cells in 15 cases (11.1%); four patients had an indolent lymphoma (follicular center cell lymphoma), and 11 patients had an aggressive lymphoma (five mantle-cell lymphomas [MCLs] and six diffuse large-cell lymphomas). Dual-color hybridization studies showed ATM deletion to be possibly a secondary aberration in three patients with MCL. Ten out of 15 ATM+/- patients had a complex karyotype, 11 out of 15 had more than 90% abnormal metaphases (AA karyotype status), and +12, 13q14 deletion, and 17p13 deletion were seen in seven, four, and five cases, respectively. Patients with ATM+/- more frequently had a complex karyotype (P =.01) and the AA karyotype (P =.04) compared with patients without ATM+/-. With the exception of a poor performance status (P =.001), no correlation was found between ATM+/-, initial clinical variables, and complete remission rate; whereas a highly significant association was found with shorter survival (P <.0001). This cytogenetic lesion maintained its prognostic importance in multivariate analysis (P =.0004), along with performance status (P =.0006), serum lactate dehydrogenase level (P =.03), splenomegaly (P =.01), and histologic grade (P =.03). When analyzing indolent lymphomas and aggressive lymphomas separately, ATM+/- maintained its prognostic importance as an independent variable in both histologic groups (P =.0001 and P =.016, respectively).

Conclusion: Though possibly not representing a primary genetic lesion in the majority of cases, the acquired ATM+/- status has clinicobiologic importance in NHL, possibly representing a major cytogenetic determinant of outcome.