Long-term follow-up of 241 patients with monoclonal gammopathy of undetermined significance: the original Mayo Clinic series 25 years later.
OBJECTIVE
To determine the long-term outcome of patients with monoclonal gammopathy of undetermined significance (MGUS).


METHODS
We reviewed the medical records of 241 patients with MGUS who were examined at the Mayo Clinic in Rochester, Minn, between January 1, 1956, and December 31, 1970.


RESULTS
Follow-up was 3579 person-years (median, 13.7 years; range, 0-39 years). Only 14 patients (6%) were alive and had no substantial increase of M protein at last follow-up; 138 patients (57%) died without evidence of multiple myeloma or a related disorder; a malignant lymphoplasma cell proliferative disorder developed in 64 patients (27%). The interval from diagnosis of MGUS to diagnosis of multiple myeloma or related disorder ranged from 1 to 32 years (median, 10.4 years).


CONCLUSIONS
The median survival rate of study patients with MGUS was only slightly shorter than that of a comparable US population. Risk of progression of MGUS to lymphoplasma cell malignancy is indefinite and persists even after more than 30 years of follow-up, with no reliable predictors of malignant evolution.
Kyle
Robert A
RA
Division of Hematology and Internal Medicine, Mayo Clinic College of Medicine, Rochester, Minn 55905, USA. kyle.robert@mayo.edu
Therneau
Terry M
TM
Rajkumar
S Vincent
SV
Larson
Dirk R
DR
Plevak
Matthew F
MF
Melton
L Joseph
LJ
D018450:Disease Progression; D005500:Follow-Up Studies; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M; D008998:Monoclonal Gammopathy of Undetermined Significance / Q000150:complications* / Q000401:mortality*; D009101:Multiple Myeloma / Q000209:etiology; D009194:Myeloma Proteins / Q000032:analysis; D013997:Time Factors
D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D009194:Myeloma Proteins; C085016:multiple myeloma M-proteins