Social Deprivation Affects Survival in Waldenström Macroglobulinaemia: Experience in the United Kingdom

Introduction:

Waldenström Macroglobulinaemia (WM) is a low-grade B-cell lymphoma characterised by lymphoplasmacytic marrow infiltration, historically described in white cohorts. The International Prognostic Scoring System for Waldenstrom Macroglobulinemia(IPSSWM) is a staging system used to stratify risk of symptomatic patients requiring treatment based on disease and patient related factors: age, haemoglobin, platelets, β-2-microglobulin and IgM. We have previously shown that outcomes in WM may be affected by ethnicity in the United Kingdom (UK). It is also known that social and economic factors influence access to healthcare and contribute to health inequality. We examined the role of such factors in presentation and outcomes of WM in a UK cohort.

Methods:

Patients diagnosed with WM from 2012-2023 with complete demographic data were retrospectively reviewed. Ethnicity was categorised according to the UK Office of National Statistics. Socioeconomic deprivation was measured by the Index of Multiple Deprivation (IMD) quintile, the established measure of relative UK deprivation from the Department of Communities and Local Government. It is a composite index derived from household postcodes (1-5: most to least deprived) and based on a weighted average of seven sub-domains (income, employment, education, health, crime, housing and living environment). Follow-up was recorded to June 2024. Overall survival (OS) and treatment-free survival (TFS) were defined from date of diagnosis to death/last follow-up and first-treatment/last follow-up, respectively. Statistical analyses were conducted using STATA v18 (STATAcorp, Texas).

Results:

Three-hundred and five patients (176 male, 129 female) were reviewed. 272 (89%) were White, 18 (6%) Asian, 5 (2%) Black, 10 (3%) were mixed/other. The median age at diagnosis was 64 (range 34-93) years. IMD quintiles were '1' in 16 patients (5%), '2' in 53 (17%), '3' in 71 (23%), '4' in 79 (23%) and '5' in 86 (28%) patients. The median IMD quintile was 4 (range 1-5) and for White, Asian, Black, Other/mixed was 4, 4, 3, 4, respectively. There was no interaction between ethnicity and IMD (p=0.21). At a median follow up of 80 months (95% confidence interval [CI] 74-89), median OS and TFS was not reached and 13 (95% CI 10-22) months, respectively. Five-year OS and TFS were 82% (95% CI 77-86) and 29% (95% CI 23-34), respectively. Of 157 evaluable treated patients, IPSSWM was categorised as: low 40% (63/157), intermediate 27% (43/157) and high 32% (51/157). One-hundred-and-fifty patients were included in a multivariable model predicting OS including IPSSWM, IMD quintile and ethnicity (Table 1). Significant predictors of OS were high IPSSWM (vs low, hazard ratio [HR] 6.42 [95% CI 2.28-18.1], p<0.001), Asian ethnicity (v White, HR 6.85 [95% CI 2.03-23.1], p=0.002) and IMD quintile (least v most deprived, HR 0.20 [95% CI 0.06-0.66], p=0.009).

Conclusions:

In our UK cohort, social deprivation as measured by IMD predicted overall survival in WM independently of IPSSWM and ethnicity. Outcome also differed by ethnicity, although numbers in the non-white cohort were low. Further analysis into subdomains of social deprivation is warranted.

Lindsay:BMS, Amgen, Takeda, BeiGene: Membership on an entity's Board of Directors or advisory committees, Other: Support for attending meetings and/or travel; Janssen, Takeda, BMS: Honoraria, Speakers Bureau. D'Sa:Cellectar: Membership on an entity's Board of Directors or advisory committees; Kite Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees; Kite Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees; BeiGene: Membership on an entity's Board of Directors or advisory committees, Research Funding.