Summary
A recent study highlighted the treatment disparities that exist among black multiple myeloma patients treated in the Veterans Health Administration (VHA), despite improved mortality compared to their non-black counterparts. Findings were presented at the 2019 ASH annual meeting (Abstract 383).
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Original Article
Understanding Multiple Myeloma Outcomes Based on Comorbidities & Race
Oncology Times
By Catlin Nalley
A recent study highlighted the treatment disparities that exist among black multiple myeloma patients treated in the Veterans Health Administration (VHA), despite improved mortality compared to their non-black counterparts. Findings were presented at the 2019 ASH annual meeting (Abstract 383).
“Our research group analyzes data from the VHA in order to avoid adverse events, reduce disparities, and improve outcomes in multiple myeloma,” noted study author Martin Schoen, MD, a hematologist/oncologist at St. Louis Veterans Affairs Medical Center. “In prior studies, we previously noticed that veterans identified as black have improved survival despite having more co-morbidities, including renal disease.”
The research team sought to better understand the potential impact of race and comorbidities in the management of multiple myeloma by studying initial treatment patterns in a nationwide population of U.S. veterans at the VHA.
Study Details
Multiple myeloma patients were identified through the VHA Central Cancer Registry between July 1, 2006, and December 31, 2013, and followed through December 31, 2014.
“We used a common comorbidity scoring system to identify co-morbid conditions from administrative codes within 12 months prior to diagnosis of multiple myeloma,” Schoen explained. “In addition, we collected laboratory data at the time of myeloma diagnosis.
“All patients in our cohort received myeloma-directed chemotherapy within 6 months of diagnosis to avoid inclusion of patients with alternate plasma cell dyscrasias (i.e., smoldering myeloma, solitary plasmacytoma, and MGUS),” he continued. “Using this dataset, we compared patients identified as black by the VHA to non-black patients in a number of variables, including administrative codes for renal disease, laboratory measurements of renal function, and treatments received by patients.”
Researchers assessed kidney function by calculation of the glomerular filtration rate with the MDRD (Modification of Diet in Renal Disease) formula, which includes black race in the calculation.
Of 2,940 multiple myeloma patients identified, 884 (30.1%) were black. “Black patients were younger with increased mean Charlson Comorbidity Index (CCI), lower mean BMI, higher GFR at diagnosis and 1-2 years prior to diagnosis, with higher rates of anemia and albumin below 3 g/dL compared to non-black patients,” the study authors reported.
Findings showed that black patients had higher rates of rates of renal disease (37.2% vs. 26.0%, p<0.001), diabetes (38.8% vs. 32.6%, p=0.001), complicated diabetes (19.0% vs. 14.7%, p=0.001), and mild liver disease (13.2% vs. 7.5%, p<0.001) based on CCI calculated from ICD codes.
“As with prior literature, we found improved survival in black patients with multiple myeloma compared to non-black patients, even after adjusting for treatment received, transplant status, medical comorbidities, and baseline laboratory data,” Schoen told Oncology Times. “Black patients had significantly higher eGFR based on the MDRD formula compared to non-black patients with conversely (or despite) higher levels of serum creatinine. Black patients were also more likely to be treated with bortezomib and less likely treated with lenalidomide.”
Implications & Next Steps
These findings highlight disparities that exist among black patients with multiple myeloma and can help clinicians gain a better understanding of the needs of this patient population.
“Our study shows increased administrative coding for renal disease and decreased use of lenalidomide in black patients despite having better calculated measurements of kidney function as determined by eGFR,” Schoen noted. “This could result from clinicians using the serum creatinine level instead of a calculated glomerular filtration rate to assess kidney function.
“Since black patients have higher creatinine levels at baseline, this could lead to higher rates of clinicians coding for renal disease and decreased treatment with lenalidomide, which requires adjustment for renal function.”
Moving forward, Schoen and his team will attempt to validate their findings in other databases to determine if a similar finding occurs beyond the VHA. “We would like to examine this question in a recent database of patients with myeloma and also determine if dosing of lenalidomide is similar between black and non-black patients,” he explained.
There are also other questions that warrant additional study. For instance, Schoen noted that, while they hypothesize that their findings “could stem from clinician misperception of renal function and resulting differences in treatment, this would require further investigation as there are many sources of disparities in cancer care.
“There may be unmeasured factors that affect clinician treatment and coding for renal disease, which we will try to assess in a future investigation,” he concluded.
Catlin Nalley is a contributing writer.