Background

Black (B) patients with Mycosis fungoides and Sézary Syndrome (MF/SS) have inferior survival and distinct clinical presentations compared to non-black (NB) patients in large registry studies from the United States. Conversely, hypopigmented MF detected only in darker skin, is associated with a favorable prognosis. We sought to characterize clinical differences in presentation, treatment, and outcomes to identify drivers of disparities among Black MF/SS patients.

Materials & Methods

We performed a retrospective review of 566 patients with stage 1A-4B MF/SS diagnosed from 1990-2020 at an academic hospital in the US. Our primary objective was to assess differences in survival between B and NB patients. Clinical variables included demographics, labs, and treatment patterns. We compared B and NB patients using 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.

Results

Among 566 patients, 257 were Black (45.4%) and 61 patients had hypopigmented MF (59 B, 3 NB). B patients were younger (median years B 50.2 vs. NB 61.7, p<0.001), female (B 57%; NB 39.8%, p<0.001), with different distributions in stage (p<0.001), higher T stage (p<0.001), nodal stage (B 39.2% Nx-N3 vs. NB 20.4%, p<0.001), and LDH at diagnosis (p<0.001). Black patients were more likely to progress to a higher stage (B 39.8% vs. NB 29.14%, p<0.001). Stage 1A was the highest stage reached in 28.4% NB patients, vs. 11% of B patients, p<0.001. There was no difference in LCT, WBC at diagnosis, TCR clonality, B or M stage, or lines of therapy by racial group.
On univariate analysis, age > 60, male gender, LCT, advanced stage, progression to a higher stage, positive TCR in the blood, elevated WBC, and elevated LDH were associated with inferior survival, while race was not. Patients with hypopigmented MF had significantly improved survival compared to patients without hypo-pigmented MF with median 10-year survival of 100% vs. 51.2%, respectively p<0.001.
On subset analysis excluding hypopigmented cases, black race was associated with inferior outcomes compared to NB after in patients age <60 (HR 1.61; CI 1.02-2.55, p=0.038), but not in patients age >60 (HR 1.20; CI 0.80-1.81, p=0.367). On multivariate analysis among the non-hypopigmented cohort with age <60 (n=270), race remained significant when controlling for stage and LCT (Black race HR 1.27; CI 1.08-2.87, p=0.43).

Conclusions

In the largest Black MF/SS cohort reported to date, we demonstrate that Black patients presented 10 years younger, with more high risk features compared to NB patients. However, survival was no different by race in part due to the unequal distribution of hypopigmented cases, a highly favorable feature found almost exclusively in Black patients. On subset analysis excluding hypopigmented MF, Black patients age<60 had significantly inferior survival compared to NB patients.