Malignancy in scleroderma patients from south west England: a population-based cohort study

The pathophysiological relationship between scleroderma and malignancy remains poorly understood. Although some previous studies have demonstrated an increased malignancy risk in patients with scleroderma, others have been inconclusive. We aimed to determine if patients with scleroderma had an increased risk of malignancy compared to an age- and sex-matched local South West England population, and if there were any important differences between scleroderma patients with and without malignancy. Methods of this study are as follows. Notes were obtained on all local scleroderma patients (n = 68) locally, and those diagnosed with malignancy verified by contacting each patient's general practitioner. Expected malignancy figures were obtained from age- and sex-stratified regional prevalence data provided by the South West Cancer Intelligence Service registry. Among the patients, 22.1% with scleroderma were identified with concurrent malignancy. Affected sites were of the breast (n = 5), haematological system (n = 5), skin (n = 4), and unknown primary (n = 1). Overall, malignancy risk was found to be increased in scleroderma (RR = 3.15, 95% CI 1.77-5.20, p = 0.01). In particular, this risk was the highest for haematological malignancies (RR = 18.5, 95% CI 6-43, p = 0.03), especially for non-Hodgkin's lymphoma (RR = 25.8, 95% CI 5-75, p = 0.10). The majority of patients (86.7%) developed malignancy after the onset of scleroderma (mean = 6.9 years). Age of > 70 and patients with limited scleroderma were significant risk factors for a patient with scleroderma to have a concurrent malignancy; however, no increased risk was found in patients with any particular pattern of organ involvement, cytotoxic usage or serology. To conclude, in this small patient cohort, we have found that scleroderma is associated with an increased risk of malignancy. This risk is statistically significant in patients with limited scleroderma. Patients who are elderly and those with limited disease should be closely scrutinized at follow-up appointments.