Cytogenetic profiles of follicular lymphoma

Abstract

To study the cytogenetic profiles of follicular lymphoma (FL) in Chinese patients. Conventional karyotype in 57 FL patients from Shanghai area was analyzed. Fluorescence in-situ hybridization (FISH) for t(14;18) and Bcl-6 and IgH gene rearrangement was performed in these cases. The most frequent breakpoints (frequency > or = 10% ) of the 57 FL cases were at band 14q32 (68.4%), 18q21 (38.6%), 3q27 (21.1%), 1q10 (15.8%) and 1q21 (12.3%). Nineteen (33.3%) of the 57 cases had t(14;18). The breakpoint of 18q21 and t(14;18) were more frequent in FL grade 1-2 and less frequent in FL grade 3 (57.6% vs. 12.5%; 54.5% vs. 4.2%, P < 0.05), whereas the 3q27/Bcl-6 rearrangement was more frequent in FL grade 3 and less frequent in FL grade 1-2 (37.5% vs. 9.1% , P < 0.05). The cohort of FL was more frequent in gains of chromosomes X, 1q, 5, 6p, 7 and 12q and losses of chromosomes 1p, 6p and 14q32. Gain of 18q was more frequent in FL grade 1-2 than in FL grade 3 (P < 0.05). Loss of 14q32 was more frequent in t(14;18) negative FL than in t(14;18) positive FL (P < 0.05). Compared with the data of Western patients reported in the literature, Chinese FL cases had distinct cytogenetic profiles from Western FL cases that the t(14;18) is less frequent and the gain of 1q is more frequent in Chinese FL cases, which are more significant in high grade FL.