Cytogenetic analysis of 147 cases of non‐Hodgkin's lymphoma: non‐random chromosomal abnormalities and histological correlations

Abstract

Summary A prospective cytogenetic study of patients with non-Hodgkin's lymphoma (NHL) presenting to one institution was commenced in 1983 as part of a larger study including histology, immunophenotyping, cytokinetics and survival. 175 patients were studied over 5 years and G-banded karyotypes were successfully obtained in 147. Chromosome abnormalities were detected in 135 cases (92%) with the commonest abnormality being t(14:18)(q32;q21) in 69 cases. Other non-random translocations were much less frequent, i.e. t(11;14) in seven cases and t(8;14) in four cases. Other specific structural changes included partial deletions of 6q (breakpoints ranging within q13-q23). 3q (breakpoints ranging within q21-q27), lq and 10q22. Chromosome regions highlighted as being frequently involved in structural abnormalities were 11q13-q25. 1p22-p36, 3q21-q27 and 6q13-q23. Several specific recurring breakpoints were identified and these included 14q32, 18q21. 1p36 and 6q21. Frequently occurring numerical abnormalities were gains of chromosomes 3, 7, × and 12. Correlation with histological type showed, as expected, that t(14:18) was present in 89% of follicular lymphoma but also occurred in 30% of diffuse lymphoma. Abnormalities of 11q were correlated with the diffuse histologies as a group, whereas both numerical and structural abnormalities of chromosome 3 correlated with the diffuse large cell lymphoma (DLCL) subtype, and t(11;14) with diffuse small cleaved cell lymphoma (DSCCL). Although not statistically significant, abnormalities of 6q occurred twice as frequently in DLCL than in any other variety. However, several other commonly occurring abnormalities, such as extra copies of chromosomes 7, ×, 12 and most of the structural abnormalities of 1p, did not correlate with any histological type. Therefore this large cytogenetic study has confirmed some previously reported correlations between specific chromosome abnormalities and histological subtypes of non-Hodgkin's lymphoma and has also identified some new correlations which may prove useful in the investigation of the biological basis of the disease.