Fracture risk with multiple myeloma: a population-based study.
Pathologic fractures, especially of the axial skeleton, are extremely common in patients with multiple myeloma and cluster around the time of diagnosis. Osteoporotic fractures seem to be less of a problem in these patients.


BACKGROUND
It is generally believed that fractures are common in patients with multiple myeloma as a result of lytic bone lesions, generalized bone loss, and/or elevated bone turnover from excessive cytokine production, but the actual risk of pathologic versus osteoporotic fractures has not been quantified.


METHODS
In a population-based retrospective cohort study, 165 Olmsted County, MN, residents with myeloma diagnosed from 1945 to 2001 (55% men; mean age, 70.7 +/- 11.1 years) were followed for 537 person-years. The relative risk of fractures was assessed by standardized incidence ratios (SIRs), and risk factors were evaluated in proportional hazards models.


RESULTS
Altogether, 134 patients experienced 463 fractures. In the year before diagnosis, 16 times more fractures were observed than expected, mostly pathologic fractures of the vertebrae and ribs. Subsequently, there was a 9-fold increase in fracture risk. However, 69% of these fractures were pathologic, and another 11% were found incidentally on myeloma monitoring. With the latter two groups excluded, subsequent fracture risk was elevated 3-fold, with a 2-fold increase in the risk of an osteoporotic fracture. In multivariate analyses, the predictors of overall fracture risk were oral corticosteroid use and elevated serum calcium levels, whereas pathologic fractures were additionally predicted by use of chemotherapy.


CONCLUSIONS
There is a dramatic increase in fractures around the time of diagnosis of myeloma, most of which are pathologic fractures. The most important predictor of overall fracture risk is oral corticosteroid use.
Melton
L Joseph
LJ
Division of Epidemiology, Department of Health Sciences Research, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA.
Kyle
Robert A
RA
Achenbach
Sara J
SJ
Oberg
Ann L
AL
Rajkumar
S Vincent
SV
D000305:Adrenal Cortex Hormones / Q000009:adverse effects / Q000627:therapeutic use; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D050723:Fractures, Bone / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000150:complications* / Q000188:drug therapy / Q000453:epidemiology; D010024:Osteoporosis / Q000453:epidemiology* / Q000209:etiology; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D013124:Spinal Injuries / Q000453:epidemiology*
D000305:Adrenal Cortex Hormones