African Americans are twice as likely to get multiple myeloma (MM) as whites, but they get the disease at younger ages.
In the past, studies comparing survival rates of white and African American patients with multiple myeloma have found disparities, with lower survival rates among African Americans tied, in part, to less access to the best treatments.
A research letter from the Veterans’ Affairs (VA) Boston Healthcare System, published in the journal Blood, reveals just how important getting the right treatment is for African Americans: when given equal access to therapy, their survival rates are just as good or better than white patients.
The findings have important implications, because multiple myeloma affects African Americans at rates twice that of than whites, while accounting for 1.8% of all malignancies in the United States.
The results bolster the argument that disparities in cancer care can be reduced if patients can simply gain access to the right treatments. A study presented in early June at the 2019 American Society of Clinical Oncology Annual Meeting found that the Affordable Care Act had helped close key racial disparities in states with Medicaid expansion because access to timely care improved.
Authors of the research letter in Blood noted that when high-dose novel agents first appeared in clinical practice, African Americans were less likely to have new agents or autologous transplants. But these new results suggest that certain disease-presenting differences may be at work. This could account for different responses to therapy among African American patients, who are diagnosed at younger ages than white counterparts.
Investigators note that in the VA system, patients have equal access to healthcare. They used data from 15,717 patients who were treated for multiple myeloma between 2000 and 2017; of these, 3254 were African American and 8845 were white veterans. Median overall survival (OS) was 4.62 years (95% CI, 4.50-4.74 years). A patient’s age at diagnosis was a major factor in OS, as follows:
For this study, the investigators examined patients in 2 groups: those 65 years and older and those younger than age 65. Even when doing this, African American patients had better OS: Investigators found that African American patients diagnosed before turning 65 had a significantly better median OS (7.07 years; 95% CI, 6.36-7.70 years) compared with white patients (5.83 years; 95% CI, 5.44-6.09 years). At age 65 and beyond, OS was similar at 3.69 years for African American patients (95% CI, 3.45-4.05 years); and 4.04 years for white patients (95% CI, 3.90-4.19 years). Even after adjusting for age, the risk of death from multiple myeloma was 24% less for African Americans under age 65 compared with white patients, while this gap closed for patients age 65 and older.
Significantly, the study found no difference between African American and white patients at the VA in the overall use of novel therapy, whether it was immunomodulatory drugs or proteasome inhibitors; 82.5% of African Americans and 81.5% of white patients received these treatments. Investigators found that in the 2012-2017 period, when these treatments had become standard of care, both groups received care at near universal levels (94% for African Americans and 93.7% for whites).
However, there were some differences in therapy choices. Bortezomib was the more frequent choice for African Americans, thalidomide used more often among white patients, and lenalidomide used at similar rates by both groups. The lenalidomide-bortezomib combination was seen more often among African Americans.
“Taken with previous research in other healthcare systems that does demonstrate disparities, our study suggests disparity may be primarily due to socioeconomic factors,” the authors wrote. Improved outcomes among African American patients with multiple myeloma, they said, “also raise an important question about possible differences in disease biology.”
Differences in age of onset, genetics, response to therapy, and OS between African Americans and white patients call for more research “to investigate race-related biological and genomic differences in the disease process to develop diagnostic, preventative, and therapeutic approaches.”
Fillmore NR, Yellapragada SV, Ifeorah C, et al. With equal access, African American patients have superior survival compared to white patients with multiple myeloma: a VA study. Blood. 2019;133:2615-2618.