Persistence of sex differences and stable trends in mortality in patients with mycosis fungoides and Sézary syndrome in Spain (1983-2022).

BACKGROUND

Mycosis fungoides (MF) and Sézary syndrome (SS) are the most common subtypes of primary cutaneous lymphomas (PCLs). Despite increasing incidence, data on mortality trends specifically for MF and SS are scarce. This study aimed to analyse mortality trends for these lymphomas in the Spanish population from 1983 to 2022.

METHODS

An ecological study was conducted using data from the Spanish National Statistics Institute. Age-standardised mortality rates (ASMRs) were calculated based on the 2013 European standard population. Changes in mortality trends were identified by joinpoint regressions. Additionally, an age-period-cohort (A-P-C) model was performed to assess the independent effects of age, birth cohort and period of diagnosis on mortality.

RESULTS

The study revealed a marked disparity in mortality rates between men and women. Male mortality was consistently higher, with a male-to-female ratio of approximately 2. The joinpoint analysis showed stable trends for both sexes throughout the study period. The A-P-C model confirmed a marked age effect, with mortality rates increasing with age for both sexes. However, the risk of dying from MF/SS remained stable across birth cohorts for both men and women.

CONCLUSION

This study found stable mortality rates for MF/SS in Spain, with relevant differences in sex and age. The lack of variation across birth cohorts suggests that age and sex are the main determinants of mortality. Further research is needed to understand the underlying reasons for these trends and develop targeted interventions to improve patient outcomes.