title: Multicentered patient-based evidence of the role of free light chain ratio normalization in multiple myeloma disease relapse.
abstract: BACKGROUND
  The normalization of free light chain ratio (FLCr) has been introduced as a marker of stringent complete remission (CR) of multiple myeloma (MM). There is currently a lack of literature assessing the role of FLCr on MM disease progression and remission status.
  
  
  METHODS
  A multicentered retrospective review of 125 patients with MM in CR and various FLCr values was completed. Parameters of interest included patient demographics, FLCr values, complete remission (CR)/relapse status, and time to progression (TTP). The FLCr values were recorded to provide time-dependent findings on the role of FLCr on progression-free survival and overall survival (OS).
  
  
  RESULTS
  The mean follow-up time of 125 patients from five hospitals in the Czech Republic was 31 months. A total of 47.2% of patients relapsed (54 of 125) during the follow-up period. The median TTP of patients with normal FLCr (n = 66) was 54.4 and 40.2 months for patients with abnormal FLCr (n = 59) (P = 0.217). None of the patients reached median overall survival regardless of FLCr values (P = 0.821). In the subgroup of newly diagnosed patients after upfront autologous stem cell transplantation (ASCT), there were 55.6% of patients (35 of 63) with normal FLCr and 44.4% (28 of 64) with abnormal FLCr. A total of 34.9% of patients (22 of 63) relapsed in this subgroup. Within the abnormal FLCr patients, a median TTP was 56.3 months, but no median TTP was reached among the normal FLCr patients (P = 0.746). Median OS in patients with normal (nFLCr) and abnormal FLCr (aFLCr) was not reached (P = 0.787).
  
  
  CONCLUSIONS
  We did not observe any benefit from FLCr normalization in CR in myeloma patients in terms of progression-free survival or overall survival.
authors: 4th Department of Medicine - Hematology, Charles University Hospital and Faculty of Medicine Hradec, Králové, Czech Republic.
authors: Jakub
authors: J
authors: Radocha
authors: Department of Internal Medicine-Hematooncology, University Hospital Brno, Brno, Czech Republic.
authors: Luděk
authors: L
authors: Pour
authors: Department of Internal Medicine III, Palacky University and University Hospital Olomouc, Olomouc, Czech Republic.
authors: Tomáš
authors: T
authors: Pika
authors: 4th Department of Medicine - Hematology, Charles University Hospital and Faculty of Medicine Hradec, Králové, Czech Republic.
authors: Vladimír
authors: V
authors: Maisnar
authors: First Department of Medicine-Department of Hematology, 1st Faculty of Medicine and General University Hospital, Prague, Czech Republic.
authors: Ivan
authors: I
authors: Špička
authors: Department of Clinical Hematology, University Hospital Kralovske Vinohrady, Prague, Czech Republic.
authors: Evžen
authors: E
authors: Gregora
authors: Department of Internal Medicine-Hematooncology, University Hospital Brno, Brno, Czech Republic.
authors: Marta
authors: M
authors: Krejčí
authors: Department of Internal Medicine III, Palacky University and University Hospital Olomouc, Olomouc, Czech Republic.
authors: Jiří
authors: J
authors: Minařík
authors: 4th Department of Medicine - Hematology, Charles University Hospital and Faculty of Medicine Hradec, Králové, Czech Republic.
authors: Kateřina
authors: K
authors: Machálková
authors: First Department of Medicine-Department of Hematology, 1st Faculty of Medicine and General University Hospital, Prague, Czech Republic.
authors: Jan
authors: J
authors: Straub
authors: Department of Clinical Hematology, University Hospital Kralovske Vinohrady, Prague, Czech Republic.
authors: Petr
authors: P
authors: Pavlíček
authors: Department of Clinical Hematology, University Hospital Ostrava, Ostrava, Czech Republic.
authors: Roman
authors: R
authors: Hájek
authors: 4th Department of Medicine - Hematology, Charles University Hospital and Faculty of Medicine Hradec, Králové, Czech Republic.
authors: Pavel
authors: P
authors: Žák
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents; D015415:Biomarkers / Q000097:blood; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000097:blood* / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D009367:Neoplasm Staging; D011379:Prognosis; D012008:Recurrence; D012074:Remission Induction; D012189:Retrospective Studies; D016019:Survival Analysis; D014182:Transplantation, Autologous
chemical_list: D000970:Antineoplastic Agents; D015415:Biomarkers; D007147:Immunoglobulin Light Chains
keywords: complete remission; free light chains; multiple myeloma; overall survival; time to progression