The risk of cancer in patients with primary Sjögren syndrome: a single-center study from Turkey

BACKGROUND: The aim of this study is to determine the risk of cancer in patients with primary Sjögren syndrome (pSS) from a single center in Turkey. METHODS: Clinical data of the subjects with pSS were retrospectively analyzed. The incidence of cancer for general population was obtained from GLOBOCAN 2018. Age- and sex-specific standardized incidence ratios (SIR) of solid and hematological cancers were calculated compared with the general population. RESULTS: Four hundred thirty patients with pSS were included in the study. The majority of the patients were female (n = 396, 92.1%), and the mean age was 58.6 ± 12.0 years. Thirty-four patients (7.9 %) were diagnosed with cancer (26 solid and 8 hematological) during follow-up. The SIR for all cancers was 2.45 (95% CI, 1.625–3.275). The SIR was 2.42 (95% CI, 1.542–3.298) for solid cancers and 8.42 (95% CI, 2.394 – 14.446) for hematological cancers. The most diagnosed malignancies were breast cancer (n = 6), ovarian cancer (n = 6), and non-Hodgkin lymphoma (NHL) (n = 4). There was an increased risk for ovarian cancer (SIR 12.76, 95% CI, 2.545–22.975). The SIR values were 2.08 (95% CI, 0.419–3.741) and 10.81 (95% CI, 0.216–21.404) for breast cancer and NHL, respectively. CONCLUSION: The risk of hematological and solid cancers was higher in the patients with pSS when compared to general population. In our pSS cohort, the risk for ovarian cancer was found to be increased, which has not been previously reported in the literature.