Osteoporosis is common among patients with multiple myeloma (MM), in part because both largely affect older adults. And more than half of MM patients will have MM skeletal-related events, which are painful, and can lead to complications (such as spinal cord compression) and death.
But how does pre-existing bone disease contribute to clinical outcomes in MM? Osteoporosis is a “silent condition” and very little is known about its role in MM, say researchers from The Ohio State University in Columbus and University of Massachusetts in Worcester. The standard diagnostic evaluation for MM does not include dual-energy x-ray absorptiometry, therefore assessments of underlying osteoporosis are not routine. Moreover, it is a challenge to distinguish osteoporotic fragility fractures from pathologic MM-induced fractures. Skeletal surveys underestimate bone involvement by about 40%, the researchers note, and are even less specific for distinguishing myeloma-related secondary osteoporosis from primary osteoporosis.
The researchers examined the relationship between the Fracture Risk Assessment Tool (FRAX) and the risk of death in women who developed MM. They analyzed data from 161,808 women in the Women’s Health Initiative (WHI). Of those, 409 developed MM; 362 had no history of cancer.
At baseline, 98 (27%) women had high FRAX scores, and 264 (73%) had low scores. The median follow-up period was 10.5 years from enrollment and 7.2 years from the time of MM diagnosis. Of the patients with MM, 226 died during the follow-up period, including 71 with high FRAX scores and 155 with low scores. MM mortality was higher among women with high FRAX scores: 72%, vs 59% of those with low scores. Poor bone health was associated with greater MM mortality but was not related to delay in time to diagnosis.
During the evaluation, 57 fractures were reported, 65% before MM diagnosis. Fewer than half of the women had a first fracture after diagnosis. The probability of fracture was similar among the women, regardless of FRAX score. Not surprisingly, older women with lower BMI were most at risk.
The WHI does not include information on staging, chemotherapy, or use of bisphosphonates. Therefore, the impact of bisphosphonates could not be determined in this study. The researchers also did not know how many patients might have had pre-existing monoclonal gammopathy of undetermined significance, a disorder in about 3% of the aging population that progresses to MM in 1% per year.
Rosko AE, Hade EM, Li W, et al. Clin Lymphoma Myeloma Leuk. 2018;18(9):597-602.