Cytogenetic evolution patterns in non-Hodgkin's lymphoma

Abstract

Secondary chromosomal aberrations were surveyed in non-Hodgkin's lymphomas (NHL) reported in the literature with one of the following, presently recognized, primary abnormalities: t(2;5), +3, t(3;14), del(6q), +X, and -Y. Of 2,175 NHLs with clonal karyotypic changes, 908 (42%) had one of the 13 selected primary chromosome rearrangements, and 670 (74%) of these lymphomas displayed additional abnormalities. The type and frequency of the secondary aberrations were ascertained and then correlated with both the type of primary abnormality and morphologic subtype; low-, intermediate, and high-grade according to the Working Formulation. The incidence of secondary aberrations differed not only among the primary abnormality subgroups, from 0% in del(11q) NHLs to 93% in t(3;14) lymphomas (P < .001) but also between B- and T-cell NHLs (78% versus 55%, P< .001) and among the different histologic subgroups: 66% in low-, 85% in intermediate-, and 71% in high-grade lymphomas (P < .001). The mean number of secondary changes per case also varied among the primary abnormalities, from none in del(11q) NHLs to 12.0 in inv(14) lymphomas (P < .001), and among the morphologic subtypes: 4.6 in low-, 6.7 in intermediate-, and 3.6 in high-grade NHL (P < .001). Recurrent secondary aberrations were found in 6 of the 13 primary abnormality subgroups: t(2;5), t(3;14), t(8;14), t(11;14), inv(14), and t(14;18). The most frequent secondary aberrations were +X, -Y, dup(1q), del(6q) varied both within and among the primary abnormalities; the most frequent imbalances were a gain of 1q23–31 and losses of 6q21, 6q23, and 6q25. Other common imbalances were deletions of 1p31–36, 1q31–44, 2q34–37, 7q35–36, 9p22–24, 11q23– 25, 13q13–21, and duplication of 12q13–22. The distribution of the secondary changes was clearly nonrandom with the most common anomalies being -Y and +7 in t(2;5); +X, del(6q), and +7 in t(3;14); dup(1q) and +7 in t(8;14); -Y, del(6q), and -13 in t(11;14); del(6q), -17, and -18 in inv(14); and del(6q), +7, and +12 in t(14;18) NHLs. In general, the secondary aberrations were similar in lymphomas of different histologic subtypes but with the same primary abnormality, although some significant differences were discerned: +3, del(6q), +7, and +18 wee more common (P < .01) in intermediate-grade than in high-grade t(8;14) NHLs; monosomy 13 occurred only in intermediate-grade t(11;14) NHLs (P < .05); and +7 and t(8;14)/t(8;22) were more frequent (P < .01 and P< .001, respectively) in high-grade than in low- and intermediate-grade t(14;18) NHLs.(ABSTRACT TRUNCATED AT 400 WORDS)