Differences in Progression and Survival Among Black Patients with Mycosis Fungoides and Sézary Syndrome: A Multicenter Retrospective Analysis at Large Urban Medical Centers

Field: Medicine (Health Sciences)

Introduction Black (B) patients with Mycosis fungoides and Sézary Syndrome (MF/SS) have inferior survival and distinct clinical presentations, including many high risk features compared to White patients. We sought to characterize clinical differences in presentation, treatment, and outcomes to identify drivers of disparities among B patients with MF/SS. Methods We performed a retrospective review of 1,197 patients with MF/SS seen between 2010 and 2021 at 7 academic institutions in the United States that serve populations with large numbers of Blacks and minorities. Patients with a confirmed histopathologic diagnosis of MF or SS on internal or external review and consistent follow up were eligible for inclusion. The primary objective was to assess differences in clinical characteristics and survival between B and non-Black (NB) patients. Clinical variables included demographics, insurance, TNMB stage at diagnosis and highest stage. Descriptive analysis was performed for each variable. Comparison between B and NB patients utilized ANOVA for numerical covariates and Chi-square test or Fisher's exact test for categorical covariates. Kaplan-Meier curves for OS were generated, and subgroups were analyzed separately by Cox Proportional hazards model. Results Self-reported race among the cohort was 508 (42.4%) Black, 638 (53.3%) White, and 51 (4.4%) were other races (14 Asian, 14 Hispanic, 2 American Indian or Alaska Native, 21 unknown). 295 patients (25.9%) progressed to a higher stage during their treatment course. The median survival of the whole cohort (n=1,045, 152 had implausible or missing survival data) was 18.3 years, (95% CI: 12.3-22.2). B patients were younger (median 51 years in B vs. 63 in NB, p<0.001), more often female (55.9% in B; 37.9% in NB, p<0.001), and had higher rates of S. aureus bacteremia during their disease course (17.6% in B, vs. 7.9% in NB, p< 0.001, table 1A). There was no difference in insurance status (private, Medicare/Medicaid, or uninsured), comorbidities, or large cell transformation by racial group. There were differences in overall TNMB stage at diagnosis (p<0.001) and T- and N-stage at diagnosis by racial group (p<0.001 for each), with Black patients generally presenting with a higher stage. There were also differences in highest stage reached (p<0.001), with different patterns of progression in the T (p<0.001) and N stage (p=0.005). Black patients had higher rates of T2b (plaque stage > 10% BSA, 11.1% vs. 21.8%), whereas NB patients had higher rates of T3 (tumor stage, 27.3% in NB vs. 17.5% in B). There were higher rates of stage progression among B vs. NB patients, p=0.025. Overall, 152 (23.4%) of NB patients progressed compared to 143 (29.3%) of B patients. The median survival for B patients was 13.1 years (95% CI 10.3, not reached) versus 21.3 years in NB patients (95% CI: 13.2, not reached), however this did not reach statistical significance in the overall cohort (figure 1B). On univariate analysis, race and gender were not associated with survival, however on subgroup analysis among patients