Single Institution Study of Abnormalities Involving Chromosomes 13 and 17 Detected by Classical Cytogenetics and Fluorescent In Situ Hybridization in Myeloma and Their Relationship to Survival in Patients Undergoing Autologous Stem Cell Transplant.

Multiple myeloma is associated with a variety of chromosomal anomalies each of which may affect survival to varying degrees. Recent data indicate that patients with chromosome 13 and 17 anomalies have a poor prognosis. In the current single institution study we analyzed the presence of anomalies involving chromosomes 13 and 17 detected by classical cytogenetics (karyotype analysis) (CC) and interphase fluorescent in situ hybridization (FISH) in patients who underwent autologous stem cell transplantation for multiple myeloma and correlated this with mean survival. Our patients had undergone autologous stem cell transplantation between April 1998 and March 2006. Of the 79 patients studied, data on CC and FISH was available on 43 patients and 29 patients respectively. 34 of 43 patients had normal CC and 11 of 29 patients had normal FISH. The mean survival of patients with normal cytogenetics was 45.36 months and for those with a normal FISH result it was 50 months. 9 of 43 patients had an abnormal CC result and 18 of 29 patients had an abnormal FISH result. Mean survival with an abnormal CC result was 30.40 months compared to 40.83 months with an abnormal FISH result. Anomalies of chromosomes 13 and/or 17 were seen in 6 of 9 patients by CC and 15 of 18 patients by FISH. Mean survival in these two groups was 30.25 months and 42.80 months respectively. These results indicate that normal cytogenetics and fluorescent in situ hybridization results at the time of diagnosis are associated with favorable outcome. The presence of abnormalities detected by conventional cytogenetics is associated with poorer outcome, particularly for deletion 13q and deletion 17p. Patients with interphase FISH abnormalities for chromosomes 13 and 17 have better survival than those with abnormalities for these chromosomes detected by conventional cytogenetics. Abnormalities in conventional cytogenetics may suggest actively proliferating disease. Thus interphase FISH should not substitute for conventional cytogenetic analysis in the diagnosis of myeloma.