DP013 | IS THERE STILL A ROLE FOR SPLENECTOMY IN THE MANAGEMENT OF SPLENIC MARGINAL ZONE LYMPHOMA?

The successful experiences of rituximab-based therapies (with or without bendamustine) in the management of splenic marginal zone lymphoma (SMZL) has led to the progressive decline in the use of splenectomy. However, it still represents a valid option for those patients with massive splenomegaly, cytopenia, low white blood cell (WBC) count and a limited bone marrow (BM) infiltration, where rapid clinical benefit is required. We conducted a monocentric retrospective study of 81 patients with SMZL who underwent splenectomy either as first line therapy (n=64; 79%) or at later treatment lines. The primary end point of the study was time to next treatment (TTNT). Secondary end points were progression free survival (PFS), overall survival (OS), overall response rate (ORR), complete response rate (CRR), post-operative complications, incidence and timing of transformation to aggressive lymphoma. Six patients had a diagnosis of SMZL with an increase in large cells (LC). BM infiltration was ≥30% and the WBC count exceeded 20.000/mmc in 49.2% and 24.7% of patients, respectively. Post-operative complications occurred in 27 patients (33.3%), most frequently splenoportal thrombosis (11.1%), pleural effusions (9.9%) and pneumonia (6.2%). The ORR was 95.1% with a CRR of 3.8%. Two patients had progression of disease (PD), and 23 patients (28.4%) relapsed. After a median follow-up of 5 years, the median PFS was 8.6 years and the median TTNT was not reached. Nineteen patients received subsequent treatment, with a median TTNT of 6.9 months. Transformation to aggressive lymphoma occurred in 7 patients (8.6%), with a median time to transformation of 3 years. Twenty-seven patients (33.3%) died, primarily due to PD (29.6%) and infections (25.9%). Only one patient died for complications related to splenectomy. The median OS was 11.3 years. Patients with an increase in LC showed a significantly worse TTNT (p=0.00055), (Fig. 1), PFS (p=0.0062) and OS (p=0.0011). Conversely, the degree of BM infiltration, WBC count and the treatment line at which splenectomy was performed had no significant impact on clinical outcomes. In our experience, splenectomy achieved high response rate and durable responses in patients with SMZL, confirming that it should still be considered a standard of care, even in later lines of therapy. The increase in LC on diagnostic specimens was associated with inferior outcomes, indicating the need for alternative therapeutic strategies in this high-risk subgroup.