Background: Non-Hodgkin's lymphoma (NHL) development in Sjögren's syndrome (SS) remains a potentially lethal complication and efforts should focus on the identification of predictors that could aid in appropriate therapeutic decisions.
Methods: In order to identify potential prognostic factors for outcome in SS-associated NHL, we retrospectively analyzed a cohort of 77 patients, diagnosed with NHL according to WHO classification criteria and meeting the American-European Consensus Classification (AECC) criteria for SS and examined the effect of SS-activity (defined as the EULAR SS disease activity index-ESSDAI) in the prognosis of SS-related NHLs, as defined in terms of overall and event-free survivals (OS and EFS). An event was defined as lymphoma relapse, treatment failure, disease progression, histological transformation or death. The effect of NHL clinical and laboratory characteristics was also investigated.
Results: MALT lymphomas constituted the majority (66.2%) of lymphomas. During the follow-up (median = 57.93 months), the 5-year OS was 90.91% (95% CI: 82.14-95.80%) and the EFS was 77.92% (95% CI: 67.37-85.82%). Patients with high ESSDAI score at lymphoma diagnosis had a greater risk for death (OR = 5.241, 95% CI: 1.034-26.568) or for event (OR = 4.317, 95% CI: 1.146-9.699, p = 0.008). These patients had also significantly worse EFS (HR = 4.541, 95% CI: 1.772-11.637) and OS (HR = 5.946, 95% CI: 1.259-28.077). In addition, post-chemotherapy ESSDAI improvement was significantly lower in patients who had experienced an event (p = 0.005). An unfavorable International prognostic index (IPI) score (high-intermediate/high) was associated with high risk of death and event (OR = 13.867, 95% CI: 2.656-72.387 and OR = 12.589, 95% CI: 3.911-40.526, respectively), worse EFS (log-rank p<0.001, HR = 8.718, 95% CI: 3.477-21.858), as well as with worse OS (log-rank p<0.001, HR = 11.414, 95% CI: 2.414-53.974). After adjustment for identified risk factors, IPI score retained a significant prognostic role following by a strong effect of ESSDAI in survival outcomes.
Conclusions: At the point of NHL diagnosis, IPI and ESSDAI might be proved useful predictive tools in SS-associated lymphoma prognosis, directing to a more patient-tailored approach.