Scleroderma and malignancy: An epidemiological study

Abstract

Objectives-Although case reports and some patient series suggest an increased risk of cancer among patients with scleroderma, there are no population based studies to support this association. A population based follow up study was therefore carried out of 233 patients with scleroderma from the six-county Uppsala health care region of Sweden for the time period 1955-84. Methods-Using the inpatient registry for the Uppsala health care region, all patients with scleroderma were identified. Their unique identification codes were then used to perform a record linkage with the National Cancer Registry. Expected cancer rates were determined using the age and gender specific rates for the Uppsala health care region. Results-The standardised incidence ratio (SIR) for all cancers among these patients was significantly increased (SIR=2.4; 95% CI=15 to 3.6). The SIRs for lung cancer (SIR=7*8; 95% CI=2-5 to 18.2) and non-Hodgkin's lymphoma (SIR=9-6; 95% CI=l.l to 34.5) were also significantly increased. Excluding patients who were diagnosed with cancer within a year of their scleroderma diagnosis resulted in similar findings, though the SIR for non- Hodgkin's lymphoma was no longer statistically significant. Conclusions-Larger population based investigations of cancer risk among patients with scleroderma are needed to confirm these initial findings and to evaluate in greater detail possible cancer risk among these patients.