title: Utility of serum free light chain measurements in multiple myeloma patients not achieving complete response to therapy.
abstract: Normalization of the serum-free light-chain ratio (FLCr) with the absence of bone marrow monoclonal plasma cells following achievement of a complete response (CR) to therapy denotes a stringent CR in multiple myeloma (MM), and is associated with improved overall survival (OS). However, its value in patients achieving <CR is not clear. We hypothesized that patients achieving a normalization of FLCr with initial therapy of MM will have an improved outcome, even in the absence of a CR. We retrospectively evaluated 449 patients with newly diagnosed MM with measurable disease at baseline, who did not achieve a CR with initial therapy. One hundred and fifty-three patients (34%) had a normal FLCr, whereas 296 (66%) had an abnormal ratio. Patients with a normal FLCr had a longer progression-free survival (29 vs 16 months, P<0.001) and OS (91 vs 58 months, P<0.001). Normalization of FLCr retained its prognostic value in a multivariable model. Our results suggest an important role for sFLC measurement in disease monitoring even in patients who achieve only a partial response to therapy. Obtaining a normal FLCr confers a favorable prognosis independent from other factors, supporting the inclusion of sFLC in all levels of response criteria.
authors.affiliation: Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: M
authors.initials: M
authors.lastname: Alhaj Moustafa
authors.affiliation: Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: S V
authors.initials: SV
authors.lastname: Rajkumar
authors.affiliation: Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: A
authors.initials: A
authors.lastname: Dispenzieri
authors.affiliation: Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Gertz
authors.affiliation: Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: M Q
authors.initials: MQ
authors.lastname: Lacy
authors.affiliation: Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: F K
authors.initials: FK
authors.lastname: Buadi
authors.affiliation: Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: Y L
authors.initials: YL
authors.lastname: Hwa
authors.affiliation: Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: D
authors.initials: D
authors.lastname: Dingli
authors.affiliation: Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: P
authors.initials: P
authors.lastname: Kapoor
authors.affiliation: Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: S R
authors.initials: SR
authors.lastname: Hayman
authors.affiliation: Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Lust
authors.affiliation: Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Kyle
authors.affiliation: Division of Hematology, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: S K
authors.initials: SK
authors.lastname: Kumar
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000097:blood* / Q000188:drug therapy* / Q000401:mortality; D009364:Neoplasm Recurrence, Local / Q000097:blood* / Q000188:drug therapy* / Q000401:mortality; D009367:Neoplasm Staging; D011379:Prognosis; D012074:Remission Induction; D012189:Retrospective Studies; D015996:Survival Rate
chemical_list: D007147:Immunoglobulin Light Chains