Disease and outcome disparities in multiple myeloma: exploring the role of race/ethnicity in the Cooperative Group clinical trials

Abstract

Multiple myeloma (MM) is an incurable hematologic malignancy with disparities in outcomes noted among racial-ethnic subgroups, likely due to disparities in access to effective treatment modalities. Clinical trials can provide access to evidence-based medicine but representation of minorities on therapeutic clinical trials has been dismal. We evaluated the impact of patient race-ethnicity in pooled data from nine large national cooperative group clinical trials in newly diagnosed MM. Among 2896 patients enrolled over more than two decades, only 18% were non-White and enrollment of minorities actually decreased in most recent years (2002-2011). African-Americans were younger and had more frequent poor-risk markers, including anemia and increased lactate dehydrogenase. Hispanics had the smallest proportion of patients on trials utilizing novel therapeutic agents. While adverse demographic (increased age) and clinical (performance status, stage, anemia, kidney dysfunction) factors were associated with inferior survival, patient race-ethnicity did not have an effect on objective response rates, progression-free, or overall survival. While there are significant disparities in MM incidence and outcomes among patients of different racial-ethnic groups, this disparity seems to be mitigated by access to appropriate therapeutic options, for example, as offered by clinical trials. Improved minority accrual in therapeutic clinical trials needs to be a priority.

Fig. 1

Overall survival of patients included in the study, by various demographic and clinical myeloma-associated characteristics studied. a Overall survival for all patients analyzed by gender. b Overall survival for all patients analyzed by patient age (≥70 or <70 years). c Overall survival for all patients analyzed by ECOG performance status (ECOG > 0 or ECOG = 0). d Overall survival for all patients analyzed by International Staging System; ISS Stage (ISS I–II or ISS III). e Overall survival for all patients analyzed by anemia (hemoglobin >10 or ≤10 g/dL). f Overall survival for all patients analyzed by kidney function (serum creatinine <2 or ≥2 mg/dL). g Overall survival for all patients analyzed by the presence of lytic lesions (presence or absence of lytic lesions). h Overall survival for all patients by the presence of hypercalcemia (serum calcium ≤12 mg/dL or >12 mg/dL)

Fig. 2

Comparison of response rates to the primary objectives of included clinical trials by patient race-ethnicity

Fig. 3

Survival outcomes for patients included in the study by race-ethnicity. a Progression-free survival (PFS) by patient race-ethnicity. b Overall survival (OS) by patient race-ethnicity