title: Both chromosome 13 abnormalities by metaphase cytogenetics and deletion of 13q by interphase FISH only are prognostically relevant in multiple myeloma.
abstract: OBJECTIVE
  Deletion of chromosome 13q [del(13q)] has emerged as a major adverse prognostic factor in multiple myeloma (MM). Del(13q) is detected two to three times more frequently by interphase fluorescence in situ hybridization (FISH) than by metaphase cytogenetics (CG). However, it has remained unclear whether or not del(13q) detected by FISH only provides the same prognostic information as its detection by CG.
  
  
  METHODS
  We investigated the outcome of 118 consecutive patients with newly diagnosed MM who were studied by both CG and FISH (RB-1 and/or D13S319 probes).
  
  
  RESULTS
  CG revealed informative MM karyotypes in 35 patients (29.7%), with monosomy 13/del(13q) in 16 of them. FISH was indicative for a del(13q) in 43 patients (36.4%). A del(13q) by FISH was present in all 16 patients with monosomy 13/del(13q) by CG and also in four of 19 patients with informative karyotypes and diploid chromosome 13. Furthermore, del(13q) was present by FISH in 23 of 84 patients with diploid/non-informative metaphases by CG. Overall survival of patients with monosomy 13/del(13q) by CG and of patients with del(13q) by FISH only was not significantly different (median, 35.2 months vs. 33.2 months, P = 0.58). In contrast, patients with diploid chromosome 13 by either technique experienced prolonged survival (median, 65.6 months). Presence of abnormal karyotypes was significantly associated with an increased Ki67 growth fraction.
  
  
  CONCLUSIONS
  FISH of chromosome 13q adds prognostic information to that provided by CG. It is suggested to use FISH analysis in clinical trials if risk stratifications take into consideration the chromosome 13q status.
authors.affiliation: Department of Medicine I, Clinical Division of Oncology and Division of Hematology, University Hospital Vienna, Austria.
authors.forename: Hannes
authors.initials: H
authors.lastname: Kaufmann
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Krömer
authors.forename: Thomas
authors.initials: T
authors.lastname: Nösslinger
authors.forename: Ansgar
authors.initials: A
authors.lastname: Weltermann
authors.forename: Jutta
authors.initials: J
authors.lastname: Ackermann
authors.forename: Regina
authors.initials: R
authors.lastname: Reisner
authors.forename: Marianne
authors.initials: M
authors.lastname: Bernhart
authors.forename: Johannes
authors.initials: J
authors.lastname: Drach
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001854:Bone Marrow Cells / Q000648:ultrastructure; D002478:Cells, Cultured; D002869:Chromosome Aberrations; D002882:Chromosomes, Human, Pair 13; D020732:Cytogenetic Analysis; D005260:Female; D017353:Gene Deletion; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007399:Interphase; D007621:Karyotyping; D008297:Male; D008677:Metaphase; D008875:Middle Aged; D009101:Multiple Myeloma / Q000235:genetics*; D011379:Prognosis