Risk and prognosis factors for systemic sclerosis with lung cancer: A single-centre case-control study in China

Abstract

Objective: To analyse clinical characteristics, risk and prognosis factors for systemic sclerosis (SSc) patients with lung cancer.

Methods: SSc patients with lung cancer admitted to Peking Union Medical College Hospital from February 1992 to December 2018 were included. Age and sex-matched controls were selected from a pool of SSc patients without lung cancer during the same period. Conditional logistic regression and Cox proportional-hazard regression were used to identify risk factors and prognosis factors. The Kaplan-Meier method was used to draw the survival curve and calculate median survival.

Results: Nineteen SSc patients with lung cancer and 76 controls were included. The mean age at lung cancer diagnosis was 54.4 ± 10.2 years. In all 19 cases the lung cancer had been diagnosed after SSc and the median interval between SSc onset and lung cancer onset was 10.5 years (range 2.0-36.2 years). Among SSc patients with lung cancer, the median follow-up time and median survival were 2.6 years and 1.4 years, respectively. In the sex and age-matched conditional logistic multivariable regression analysis, family history of malignancy (OR 4.930, 95%CI 1.926-12.619, P = .001), ILD (OR 7.701, 95%CI 1.009-58.767, P = .049) were independent risk factors for lung cancer among SSc patients, and considering sex and age of SSc onset, SSc patients with more advanced staging of lung cancer (HR 3.190, 95%CI 1.127-6.126, P = .06) had poorer prognosis.

Conclusion: Lung cancer is not uncommon in SSc patients, especially those with family histories of malignancy or ILD. Early detection of lung cancer is of vital importance for better prognosis.