Risk of malignancy in scleroderma: a population-based cohort study

Area of Science:

• Rheumatology
• Oncology
• Epidemiology

Background:

• Scleroderma (systemic sclerosis) is an autoimmune disease with potential associations with various cancers.
• Previous studies have suggested an elevated cancer risk in patients with scleroderma, but findings have been inconsistent.
• Understanding cancer incidence in scleroderma patients is crucial for patient management and risk stratification.

Purpose of the Study:

• To investigate the incidence of specific cancers in patients diagnosed with scleroderma.
• To compare cancer rates in scleroderma patients with those in the general population of the Detroit metropolitan area.
• To identify any demographic or racial disparities in cancer risk among scleroderma patients.

Main Methods:

• Utilized data from the Michigan Scleroderma Registry and the Metropolitan Detroit Cancer Surveillance System.
• Linked patient records to assess cancer risk between 1973 and 2002, with follow-up to 2004.
• Calculated standardized incidence ratios (SIRs) for lung, liver, colon, breast, cervical, prostate cancers, and non-Hodgkin's lymphomas, stratified by sex and race.

Main Results:

• Of 538 eligible scleroderma patients, 45 were diagnosed with a first malignancy.
• Lung cancer was the most common malignancy but did not show a significantly increased incidence compared to the general population (SIR 1.23).
• Black females with scleroderma exhibited a significantly higher incidence of liver cancer (SIR 45.8); other cancers showed no significant differences.

Conclusions:

• This study found no overall increased cancer incidence in scleroderma patients, contrary to some prior research.
• A notable exception was the significantly elevated risk of liver cancer observed in Black females with scleroderma.
• The findings underscore the importance of considering local population cancer rates when evaluating scleroderma cohorts and highlight a specific risk for liver cancer in a subgroup.