Abstract
The rate of concomitance of systemic sclerosis and malignant neoplasm is not still ascertained. Therefore we reviewed 8,327 patients who were diagnosed with systemic sclerosis and received public financial aid from the Ministry of Health, Labour and Welfare of Japan in 1999. The concomitance rate was 3.1% of all patients, however, it was more frequent among men than among women (5.4% for men and 2.8% for women, respectively, P<0.01), and the mean age of patients with complicated malignant neoplasms was significantly higher than that of patients without malignancy (P<0.01). For comparison with the Japanese general population, O/E ratios (ratio of observed-to- expected malignant neoplasms) were calculated, and it was found that both men and women had significantly higher O/E ratios (O/E ratio 2.31, 95% confidence interval [CI] 1.68-2.94, P<0.001 for men and O/E ratio 1.64, 95% CI 1.41-1.86, P<0.001 for women). In addition we also assessed laboratory findings including autoantibodies and respiratory function tests for patients with malignant neoplasms by logistic regression analysis adjusted for sex and age. Decreased DLco (pulmonary CO diffusing capacity) appeared to be a risk factor for the concomitant malignant neoplasms among patients with systemic sclerosis (odds ratio 2.00 for DLco ≦70%, CI 1.06-3.74, P=0.032). These results may help to elucidate the etiology of systemic sclerosis.
