Abnormalities involving chromosome 6 in newly diagnosed patients with non-Hodgkin's lymphoma

Several cytogenetic abnormalities involving chromosome 6 occurring in Non-Hodgkin's lymphoma (NHL) have been described. We report 34 newly diagnosed patients with NHL who had an abnormal chromosome 6 on initial biopsy. Monosomies (n = 5), trisomies (n = 6), deletions of 6q (n = 13), and isochromosomes 6p (n = 9) were frequently observed and translocations were rare. As compared with 70 other NHL patients with cytogenetic abnormalities, the patients with an abnormal chromosome 6 had a higher frequency of immunoblastic lymphoma (p < 0.001). These patients also were more likely to have B symptoms (p = 0.02). Patients with a breakpoint at 6q11-16 all had a deletion of the distal portion and also were more likely to have B symptoms (p < 0.001). Most patients with breakpoints at 6q21-25 had a deletion associated with a lower frequency of stage IV disease (p = 0.03) and a higher complete remission (CR) rate (p = 0.03). The patients with an i(6p) had a lower frequency of stage IV disease (p = 0.03), and the patients with a trisomy 6 had a shorter median survival (p = 0.005). Our results suggest that chromosome 6, especially the long arm, carries important information for the clinical behavior of NHL. Future studies are necessary to resolve the molecular defects.