Treatment modalities of marginal zone lymphoma and overall survival, haematological response, and underlying Sjögren's disease activity: a multicentre, retrospective, observational study.

Background: Sjögren's disease is the autoimmune disease with the highest risk of lymphoma development. There is no consensus on the optimal way to manage Sjögren's disease complicated by lymphoma. We aimed to describe characteristics, therapeutic strategies, and outcomes of non-Hodgkin lymphoma associated with Sjögren's disease, and their effect on lymphoma and Sjögren's disease prognoses.

Methods: We did a multicentre, retrospective, observational study including patients with Sjögren's disease according to the 2016 American College of Rheumatology-European League Against Rheumatism criteria who did not fulfil diagnostic criteria for other connective tissue diseases. We included patients with a lymphoma diagnosis made before Jan 1, 2020, from two expert centres in Paris (France); from the French, multicentre, prospective Assessment of Systemic Signs and Evolution of Sjögren's Syndrome cohort; and via practitioners registered with the Club Rhumatismes et Inflammation. Using inverse probability of treatment weighting, the effect of lymphoma treatment was compared in relation to three endpoints: lymphoma progression-free survival, new Sjögren's disease systemic activity, and overall survival. Exploratory analyses also aimed to identify factors associated with lymphoma relapse, new Sjögren's disease systemic activity, and overall survival. People with lived experience were not involved in this research.

Findings: 106 patients with Sjögren's disease who developed lymphoma were included in the study. The most frequent histological subtype was mucosa-associated lymphoid tissue lymphoma (68 [64%] of 106 patients), followed by other marginal zone subtypes (14 [13%] of 106 patients) and diffuse large B-cell lymphoma (14 [13%] of 106 patients). Among the 82 patients with marginal zone lymphoma (72 [88%] women and ten (12%) men; mean age at lymphoma diagnosis 57·5 years [SD 14·8]), multivariable analysis showed that pulmonary localisation was associated with mortality (hazard ratio [HR] 7·92 [95% CI 1·70-37·0]). A watch and wait approach was proposed in 19 (23%) of 82 patients with marginal zone lymphoma, 13 (16%) had first-line localised treatment (surgery or radiotherapy), and 50 (61%) had first-line systemic treatment. After a median follow-up of 7 years, 26 patients (32%) had lymphoma relapse, nine (11%) died, and 27 (33%) had new Sjögren's disease systemic activity. After inverse probability of treatment weighting, patients with systemic treatment at lymphoma diagnosis had a reduced risk of new Sjögren's disease activity (HR 0·43 [95% CI 0·21-0·90]). When comparing patients treated with a combination of chemotherapy and anti-CD20 therapy (n=32) with patients treated with monotherapy (n=18) as a first-line therapy for lymphoma, lymphoma-progression-free survival was improved in patients treated with combination therapy (HR 0·36 [95% CI 0·14-0·94]). The were no differences in new Sjögren's disease systemic activity or overall survival according to combination therapy or monotherapy.

Interpretation: A systemic treatment strategy for Sjögren's disease-associated lymphoma, rather than localised treatment or a watch and wait strategy, reduces the risk of new Sjögren's disease systemic activity and combination therapy is associated with decreased risk of lymphoma relapse.

Funding: None.