Mortality and Survival Analysis in Patients With Cancer Occurrence After Sjögren's Syndrome: A Long-Term Cohort Study in China.

Abstract

Objective: This study aimed to investigate the mortality, survival rates, and prognostic indicators of cancer occurrence after Sjögren's syndrome (SS-CA).

Methods: The medical records of patients with SS-CA at the Peking Union Medical College Hospital (PUMCH) between January 2010 and August 2022 were retrieved. Clinical data and survival outcomes were compared to controls. The standard mortality ratio (SMR) versus the general population was calculated, and the survival and predictive markers of prognosis were analyzed using Kaplan-Meier curves and Cox regression.

Results: In total, 114 SS-CA patients were included, with a median follow-up time of 105.1 (57.3-168.0) months. Non-Hodgkin lymphoma (32, 28.1%) was the most common cancer in patients with SS-CA. The SMR of SS-CA patients was 2.61 (95% confidence interval [CI] 1.73-3.77). Patients with SS-CA exhibited significantly inferior outcomes compared to controls (p = 0.010), with 5- and 10-year overall survival rates of 91.2% and 83.2%, respectively. SS patients with a diagnostic interval between SS and cancer (SS-CA diagnostic interval) ≤ 3 years or with hematological malignancies had poorer survival compared to those with a diagnostic interval > 3 years (p < 0.001) or with solid tumors (p = 0.019). Multivariate Cox regression analysis identified the prognosis-associated factors of SS-CA as age at SS diagnosis > 50 years (HR 3.129, 95% CI 1.224-7.998; p = 0.017), SS-CA diagnostic interval ≤ 3 years (HR 7.754, 95% CI 1.953-30.781; p = 0.004), and hematological malignancies (HR 2.648, 95% CI 1.201-5.838; p = 0.016).

Conclusion: Malignant comorbidities constituted a poor prognosis in patients with SS, wherein the SS-CA diagnostic interval and the types of cancer were associated with survival.