Haematological malignancies in systemic sclerosis: a population-based nationwide register study.

Area of Science:

• Rheumatology and Hematology
• Epidemiology and Public Health

Background:

• Systemic sclerosis (SSc) is a complex autoimmune disease with potential links to secondary malignancies.
• Understanding the specific cancer risks associated with SSc is crucial for patient monitoring and management.

Purpose of the Study:

• To evaluate the risk of hematological malignancies in patients with SSc compared to the general population.
• To investigate how this risk differs based on sex and age.
• To determine the temporal relationship between SSc diagnosis and the onset of these malignancies.

Main Methods:

• A nationwide cohort study utilizing Swedish administrative healthcare registers from 2004-2019.
• Inclusion of SSc patients and matched general population comparators.
• Analysis of hematological malignancy incidence using Poisson regression and hazard ratios (HRs) via flexible parametric models, stratified by sex and age.

Main Results:

• Individuals with SSc showed a 2.2-fold increased risk of hematological malignancies (HR 2.2, 95% CI 1.4-3.1), with a 3.0-fold risk for B-cell malignancies (HR 3.0, 95% CI 1.7-4.8).
• The risk was notably higher in men and in individuals aged 18-49 years at SSc diagnosis.
• Myeloid malignancies presented near the time of SSc diagnosis (median 0.1 years post-diagnosis), while lymphoid malignancies appeared later (median 3.1 years post-diagnosis).

Conclusions:

• Patients with SSc face a significantly elevated risk of hematological malignancies, especially B-cell types.
• Men with SSc exhibit the highest risk.
• The timing of malignancy presentation differs, with myeloid types occurring closer to SSc diagnosis than lymphoid types.