title: Features of extramedullary disease of multiple myeloma: high frequency of p53 deletion and poor survival: a retrospective single-center study of 834 cases.
abstract: BACKGROUND
  Multiple myeloma (MM) is a heterogeneous disease in which most patients have myeloma restricted to the bone marrow, and some patients develop extramedullary disease (EMD) at the time of diagnosis or during follow-up, and show different clinical characteristics and a dismal prognosis.
  
  
  METHODS
  We studied 834 consecutive MM patients in a single center in China and compared clinical features of patients with and without EMD.
  
  
  RESULTS
  In general, the prevalence of EMD was 4.8% at the time of diagnosis and 3.4% during follow-up, with a significant increase in recent years. MM patients with EMD at the time of diagnosis had remarkably greater prevalence of P53 deletion determined using fluorescence in situ hybridization (FISH) analysis (34.5% vs. 11.9%; P = .037) and higher level of lactate dehydrogenase (LDH) (P = .003) compared with patients without EMD. EMD relapse/progression during follow-up was correlated with EMD presentation at diagnosis, immunoglobulin (Ig)D subtype and P53 deletion in FISH analysis, but not previous treatment (thalidomide, bortizomib, or transplantation). With respect to prognosis, multivariate analysis showed that EMD was an independent adverse prognostic factor. The overall survival of patients with and without EMD at diagnosis were 16.5 and 40 months, respectively (P < .001), and the time to disease progression of the 2 groups was 11.5 and 25 months, respectively (P < .001).
  
  
  CONCLUSIONS
  MM patients with EMD at the time of diagnosis showed remarkably greater prevalence of P53 deletion in FISH analysis and higher LDH levels. EMD relapse/progression was correlated with EMD presentation at diagnosis, IgD subtype, and P53 deletion in FISH analysis, but not previous exposure to new drugs or transplantation. The presence of EMD involvement negatively affected survival.
authors: State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College.
authors: Shuhui
authors: S
authors: Deng
authors: State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College.
authors: Yan
authors: Y
authors: Xu
authors: State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College.
authors: Gang
authors: G
authors: An
authors: State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College.
authors: Weiwei
authors: W
authors: Sui
authors: State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College.
authors: Dehui
authors: D
authors: Zou
authors: State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College.
authors: Yaozhong
authors: Y
authors: Zhao
authors: State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College.
authors: Junyuan
authors: J
authors: Qi
authors: State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College.
authors: Fei
authors: F
authors: Li
authors: State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College.
authors: Mu
authors: M
authors: Hao
authors: State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College. Electronic address: drqiu99@medmail.com.cn.
authors: Lugui
authors: L
authors: Qiu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018450:Disease Progression; D005260:Female; D005787:Gene Frequency; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000235:genetics / Q000401:mortality / Q000473:pathology*; D015999:Multivariate Analysis; D009154:Mutation; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D016896:Treatment Outcome; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*
chemical_list: C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53
keywords: Extramedullary disease; Multiple myeloma; P53 deletion; Prognosis