Cancers in systemic sclerosis : risk factors, impact on survival and literature review

Patients with systemic sclerosis (SSc) have an increased risk of malignancy. In this study, we aimed to analyze the prevalence of cancer, the risk factors and the impact on overall survival. We analyzed clinical (history of cancer, toxic exposition, organ involvement), immunological and treatment data in a monocentric cohort of SSc patients followed between January 2004 and December 2017. Two hundred and ten patients with SSc were included. During the follow-up, twenty-one patients (10 %) were diagnosed with malignancies. The underlying malignancies were breast adenocarcinoma (n=6, 28%), lung cancer (n=6, 28%), colorectal (colic adenocarcinoma, carcinoid tumor of the appendix), ovarian and cervix uteri, melanoma, kidney and papillary thyroid carcinoma (one of each). The median time between the first visit and the diagnosis of cancer was 4 [2-10] years. The overall survival in SSc patients with cancer was not significantly different from patients without cancer, with median survival during the first quartile (75%) at 12 years for patients with cancer and 11.6 years for those without cancer (P=0.9). The history of renal scleroderma crisis (HR 10.99, IC95% [1.95-62.07]; P=0.006) and the presence of anti-topoisomerase I antibodies (HR 5.5, IC95% [1.40-21.67]; P=0.01) were associated with an increased risk of cancer, whereas the presence of gastroesophageal reflux was inversely associated with the cancer occurrence (HR 0.22, IC95% [0.056-0.867]; P=0.03). The history of renal scleroderma crisis and the positivity of anti-topoisomerase I antibodies were associated with an increased risk of cancer in SSc patients in this monocentric study.