Prognostic Impact of Gastrointestinal Involvement in Newly Diagnosed Diffuse Large B-Cell Lymphoma
Authors: Kasouha David , Lehners Nicola , Kriegsmann Katharina , Egerer Gerlinde , Ho Anthony D , Witzens-Harig Mathias 
Published: October 2019

Abstract
Introduction: Involvement of >1 extranodal site is regarded as a poor prognostic factor for patients with diffuse large B-cell lymphoma (DLBCL). It is necessary to clarify the prognostic impact of specific extranodal sites. Gastrointestinal (GI) involvement is one of the most frequently involved extranodal sites.
Methods: Patients with newly diagnosed DLBCL treated at the University of Heidelberg between 06/2001 and 07/2015 were identified and included in this retrospective analysis. Data on clinical characteristics and treatment modalities were obtained by review of medical charts. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. The impact of variables on PFS and OS was evaluated by univariate log-rank tests and by multivariate analysis using the Cox proportional hazards model.
Results: A total of 1001 patients were identified of whom 119 (11.9%) presented with GI involvement. Median age of patients with GI involvement was 63.3 years [range 19.1-86.7], 71 (59.7%) were male. 92 patients had an available international prognostic index (IPI) score, 36 (39.1%) IPI 0-1, 33 (35.9%) IPI 2-3, and 23 (25%) IPI 4-5. The most frequently involved organs of GI were stomach (51.3%), small intestine (39.5%), colon (20.2%), and esophagus (2.5%).
107 (89.9%) patients were treated in curative intent and were further analyzed regarding the prognostic impact of several factors on outcome. 80.4% of them received CHOP-like therapies, 17.8% received chemotherapy more aggressive than CHOP, typically addition of etoposide or treatment with high-dose methotrexate in case of CNS involvement, 87.9% received additional rituximab, and 22.4% additional radiotherapy
In DLBCL patients with GI involvement, we identified factors associated with worse OS (P<.05) by univariate analysis: B symptoms, elevated serum LDH, and involvement of more than two extranodal sites. On the contrary, age (>60 years), sex, Ann Arbor Stage (AAS) III/IV, and Performance Status of Eastern Cooperative Oncology Group
(ECOG) more than one, and elevated serum sCD25 did not have any significant impact on OS. B symptoms were as well associated with decreased PFS (P<.05) by univariate analysis.
Multivariate Cox Regression analysis revealed that patients with elevated serum LDH at diagnosis had significantly worse OS (P<.05), and patients with B symptoms had significantly worse PFS (P<.05).
Regarding first-line treatment modalities, escalation of chemotherapy to more aggressive regimes than CHOP was associated with a prolonged OS and PFS in univariate analysis, not in multivariate analysis. Radiotherapy did not have any significant impact on OS or PFS.
Regarding all DLBCL patients treated with curative intent, GI involvement did not have any significant prognostic impact on OS or PFS.
Conclusions: In this retrospective registry analysis of patients with newly diagnosed DLBCL with GI involvement, B symptoms, elevated serum LDH, and involvement of more than two extranodal sites were identified as risk factors for inferior OS. Escalation of chemotherapy to more aggressive regimes than CHOP was associated with a prolonged OS and PFS.
Further analyses are required as toward which treatment modalities might be best suited to improve prognosis of GI involvement.

Disclosures
Kriegsmann: Celgene: Research Funding; BMS: Research Funding.