Among elderly Medicare patients with multiple myeloma (MM) the chronic-kidney disease (CKD)-associated clinical burden is substantial, according to the results of a new study.
CKD occurs commonly with symptomatic MM, according to the study.
“The main cause of renal dysfunction is the toxicity of immunoglobulin light chain deposition in the renal tubes,” the researchers wrote in Clinical Lymphoma, Myeloma & Leukemia. “In addition to MM-related kidney damage, other factors that may contribute to renal damage include dehydration, infection, hypercalcemia, and nephrotoxic drugs used to treat MM.”
This studied identified 22,484 elderly Medicare beneficiaries diagnosed with MM who initiated first-line therapy from 2008 to 2014. Of these patients, 39% had CKD at first-line therapy initiation. Patients with CKD had a shorter median overall survival compared with those without CKD (2.1 vs. 3.6 years).
Additionally, patients with CKD were more likely to advance to the next line of therapy or die than patients without CKD at each line of therapy (P<.001 for all lines).
Lower rates of skeletal-related events (SREs) of any type were found in patients with CKD compared with patients without CKD. The researchers noted that this “finding may be owing to misclassification in identifying SREs because the algorithm we employed in the study was originally developed for patients with primary breast or prostate cancer and adapted in several studies for patients with metastatic breast or prostate cancer to bone.”
When the researchers adjusted for patients’ baseline characteristics, patients with MM and CKD had higher risk for all-cause death, advancing to next line of therapy or death, and developing anemia or hypercalcemia compared with those without CKD.
The researchers noted several caveats to their findings including use of diagnostic codes to define CKD, the retrospective nature of the study, and lack of knowledge about who had pre-existing CKD and who developed CKD because of MM.
“Data from the study suggest that CKD-associated clinical burden is substantial in elderly patients with MM,” the researchers wrote. “Further studies are needed to understand the reasons for the observed reduced risk for SRE events of any types associated with CKD.”