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Normalization of free light chain kappa/lambda ratio is a robust prognostic indicator of favorable outcome in patients with multiple myeloma
Author(s) -
Iwama Kanichi,
Chihara Dai,
Tsuda Kenji,
Ugai Tomotaka,
Sugihara Hiroyuki,
Nishida Yuhki,
Yamakura Masayuki,
Takeuchi Masami,
Matsue Kosei
Publication year - 2013
Publication title -
european journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.904
H-Index - 84
eISSN - 1600-0609
pISSN - 0902-4441
DOI - 10.1111/ejh.12050
Subject(s) - medicine , multiple myeloma , immunoglobulin light chain , gastroenterology , multivariate analysis , univariate analysis , kappa , normalization (sociology) , confidence interval , progression free survival , oncology , overall survival , immunology , antibody , linguistics , philosophy , sociology , anthropology
Purpose To clarify the impact of serum free light chain ( sFLC ) ratio normalization in patients with multiple myeloma ( MM ) treated with novel agents. Patients and methods Treatment response in 126 consecutive patients over 7 yr was assessed by IMWG criteria and s FLC assay. Results Thirty‐four patients (27%) showed complete response (CR), 37 (29%) very good partial response ( VGPR ), 39 (31%) partial response (PR), and 16 (13%) stable disease ( SD ) or less at a median follow‐up of 28 months. Fifty‐two patients (41%) with s FLC ratio normalization showed superior progression‐free survival (PFS) and overall survival ( OS ) compared to those who did not (3‐yr OS, 94% vs. 48%; P < 0.001). This favorable effect of s FLC ratio normalization occurred irrespective of high (>1000 mg/dL) or low (<100 mg/dL) baseline s FLC . Rates of normal s FLC ratio were as follows: CR , 69%; VGPR , 64%; PR, 16%; and SD or less, 0%. OS was significantly superior in patients with than without normal s FCL ratio in respective response groups. Although various factors (advanced age >70, high LDH , ISS stage 3) showed negative prognostic impacts on PFS and OS on univariate analysis, normal s FLC ratio and achievement of CR emerged as the strongest prognostic predictors for longer OS in MM patients on multivariate analysis. Conclusions This study demonstrated the significance of obtaining normal s FLC ratio independent of other clinical variables. Analysis of sFLC ratio could identify the favorable group of patients as well as immunofixation test and support the inclusion of sFLC ratio as part of the response criteria for MM.