Relationship between Social Deprivation Index, Race and Survival Outcomes Among Multiple Myeloma Patients in a Large, Diverse Population of New York

Background

The Social Deprivation Index (SDI) is a composite measure derived from demographic characteristics collected in the American Community Survey (ACS) and provides an estimate of social deprivation, with higher scores indicating greater deprivation (1). Some studies have suggested significant interaction exists between individual low-income status and area deprivation on mortality (2). This study aims to explore the relationship between SDI, race, and survival outcomes in multiple myeloma (MM) patients within our health system, serving very diverse neighborhoods of New York.

Methods

This single-center retrospective study included 208 multiple myeloma (MM) patients treated with radiotherapy (RT) between 2008-2023 at Northwell Health. Patients without a MM diagnosis, initial diagnostic data, or follow-up were excluded. Data on patient demographics, MM risk status (based on cytogenetics and Revised International Staging System criteria), RT frequency, and SDI matched to the patients’ zip code data were collected. Statistical analysis was performed using Stata v.18. High-risk patients included those with FGFR3/IGH fusion or t(4;14), MAF/IGH fusion or t(14;16), IGH/MAFB fusion or t(14:20), TP53 (17p) deletion, 1q amplification, or stage 2/3 disease. Kaplan-Meier and log-rank testing were used to compare time-to-event data.

Results

The study included 124 patients, with race data available for 121 patients. The median age at diagnosis was 66 years, and 51.6% of the patients were male. The racial distribution was African American/Black (AA) (35.54%), White (28.93%), Asian (6.61%), American Indian or Alaska Native (1.65%), and other races (27.27%). Notably, the median age at diagnosis was significantly older in women compared to men (67 vs. 62 years, p=0.03). The median SDI scores were 67 for American Indian or Alaska Native (n=2), 43.75 for Asians (n=8), 53.25 for African American/Black patients (n=43), 31.31 for White patients (n= 35) and 56.72 for other races (n= 33). SDI scores varied significantly among racial groups (p=0.001), with White patients having the lowest median SDI scores, indicating less social deprivation. The median follow-up duration was 30 months. The median overall survival (OS) for high-risk patients was 48.47 months, whereas it was not reached for standard-risk patients [HR 4.35, 95% CI: 2.25-8.39, p<0.001]. When comparing OS across racial groups, White patients had a median OS of 56.6 months, whereas it was 121.8 months for non-White patients [HR 1.9, 95% CI 0.89-4.06, p=0.057]. For AA patients, the median OS was not reached when compared to White patients [HR 0.65, 95% CI 0.3-1.4, p=0.27]. Within the high-risk subgroup, the median OS for White vs. non-White patients was 48.47 vs. 87.77 months [HR 1.47, 95% CI 0.65-3.3, p=0.313], and for White vs. AA patients, it was 48.47 months vs. not reached [HR 1.47, 95% CI 0.58-3.7, p=0.421].

Discussion

Despite significantly lower SDI scores, White patients in our study cohort showed a trend towards lower OS. AA patients, despite having higher SDI when compared to White patients, appeared to have better survival across all risk groups. This finding contrasts with some existing literature suggesting lower survival in AA patients. Fillmore et.al. has also described that AA patients can have superior OS with equal access to care (3). Although our study is limited by sample size, the findings highlight the need for further investigation into factors contributing to the observed OS trends in White patients, such as environmental influences or tumor biology. Additionally, further exploration is needed to identify factors that may have helped improve survival outcomes in our AA patients, such as effectiveness of resource utilization to address socioeconomic barriers or differences in disease biology.

References

1. Social deprivation index (SDI). Robert Graham Center - Policy Studies in Family Medicine & Primary Care. Accessed June 29, 2024.

2. Hong YD, Mullins CD, Onukwugha E, Yared JA, Zheng Z, Slejko JF. Association of individual low-income status and area deprivation with mortality in multiple myeloma. J Geriatr Oncol. 2023;14(2):101415. doi:10.1016/j.jgo.2022.12.003

3. 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(24):2615-2618. doi:10.1182/blood.2019000406