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3905 The Absolute Number of Extranodal Sites Detected By PET-CT Is a Powerful Predictor of Secondary Central Nervous System Involvement in Patients with Diffuse Large B-Cell Lymphoma Treated with R-CHOP

Non-Hodgkin Lymphoma: Biology, excluding Therapy
Program: Oral and Poster Abstracts
Session: 622. Non-Hodgkin Lymphoma: Biology, excluding Therapy: Poster III
Monday, December 7, 2015, 6:00 PM-8:00 PM
Hall A, Level 2 (Orange County Convention Center)

Chan Yoon Cheah, MBBS DMedSc1,2,3,4, Martin Hutchings, MD5*, Kirsty Rady, MBBS6*, Kerry J. Savage, MD, MSc7, Musa F. Alzahrani, MBBS, ABIM8, Laurie H. Sehn9, Sally Barrington, MD10*, George Mikhaeel, MD11*, Roopesh R. Kansara, MD12, Jakob Werner Hansen, MD13*, Daniel Smith, MD14*, Karen Juul Mylam, MD15*, Thomas Stauffer Larsen, MD, PhD16*, Staffan Holmberg, MD17*, Maja Juul, MD18*, Sabrina Cordua, MD19, Michael Roost Clausen, MD20*, Kkristina Buchardi Jensen21*, Martin Bogsted22*, Hans Erik Johnsen, Professor, MD23, Joseph M. Connors, MD9, Peter de Nully Brown24, John F. Seymour, MBBS, PhD25,26, Diego Villa, MD, MPH7 and Tarec Christoffer El-Galaly27*

1School of Pathology and Laboratory Medicine, University of Western Australia, Perth, Australia
2Department of Haematology, Sir Charles Gairdner Hospital, Perth, Australia
3Department of Haematology, Pathwest Laboratory Medicine WA, Perth, Australia
4Department of Haematology, Peter MacCallum Cancer Centre, Melbourne, Australia
5Department of Hematology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
6Department of Haematology, Peter MacCallum Cancer Centre, East Melbourne, Australia
7BC Cancer Agency and University of British Columbia, Centre for Lymphoid Cancer, Vancouver, BC, Canada
8Department of Hematology, Faculty of Medicine, University of British Columbia, University of British Columbia, Vancouver, BC, Canada
9British Columbia Cancer Agency, Centre for Lymphoid Cancer and Department of Medical Oncology, Vancouver, BC, Canada
10Guy's and St. Thomas' Hospital and Kings College, London, United Kingdom
11Medical Oncology, Guy's and St Thomas' NHS Trust, London, United Kingdom
12Centre for Lymphoid Cancer and Division of Medical Oncology, British Columbia Cancer Agency, Vancouver, BC, Canada
13Department of Haematology, Rigshospitalet, Copenhagen, Denmark
14Guy's and St Thomas' NHS Trust, London, United Kingdom
15Department of Haematology, Odense Univsersity Hospital, Odense, Denmark
16Department of Hematology, Odense University Hospital, Odense, Denmark
17Department of Haematology, Herlev Hospital, Copenhagen, Denmark
18Department of Haematology, Vejle Hospital, Vejle, Denmark
19Department of Hematology, Roskilde University Hospital, Roskilde, Denmark
20Hematology, Aarhus University Hospital, Aarhus, Denmark
21Department of Haematology, Holstebro Hospital, Holstebro, Denmark
22Unit of Biostatistics, Aalborg University Hospital, Aalbord, Denmark
23Department of Haematology, Aalborg University Hospital, Aalborg, Denmark
24Department of Oncology, Copenhagen University Hospital, Copenhagen, Denmark
25Peter MacCallum Cancer Centre, Melbourne, Australia
26University of Melbourne, Melbourne, Australia
27Department of Hematology, Aalborg University Hospital, Aalborg, Denmark

Background

Central nervous system (CNS) relapse in patients with diffuse large B-cell lymphoma (DLBCL) is an infrequent but devastating complication. The German Risk model which includes the 5 IPI risk factors plus involvement of the kidneys has been validated in 2 large independent cohorts (Schmitz, ICML 2013; Savage, ASH 2014; El-Galaly, ICML 2015). In this model, the presence of >1 extranodal site of involvement contributes only 1 point. However, the precise impact of the extent of extranodal disease in PET-CT staged patients is unknown. Patients and Methods

We identified patients with newly diagnosed DLBCL presenting to hospitals in Denmark, Canada, the United Kingdom and Australia through systematic searches of national/local lymphoma registries. Inclusion criteria were: staging included PET-CT, primary treatment with R-CHOP or similar regimen ± CNS prophylaxis. Patients treated with high-dose regimens (such as R-HyperCVAD) and those with CNS involvement at diagnosis were excluded. Medical records and PET-CT reports were reviewed for clinical information and outcome. Multiple lesions in one organ or set of paired organs/ tissue were counted as a single extranodal site, and the spleen and Waldeyer's ring were not included as extranodal sites. Time to CNS relapse was determined using the method of Kaplan and Meier, with univariate analysis of absolute number of extranodal sites associated with CNS relapse performed using competing risk regression with death before CNS relapse as competing risk. Multivariate analyses (adjusted for elevated LDH, age>60 y and performance status>1) were performed using Cox proportional hazards to identify the specific increase in risk attributable to the absolute number of extranodal sites of involvement.  Involvement of the kidney/adrenals and advanced disease stage were not included in the adjustment because of their intrinsic relationship to number of extranodal sites. Results

1,536 patients meeting the above criteria were included, with the following characteristics: median age 65 y (range 17-92), 63% stage III/IV, 39% B symptoms, 50% elevated LDH, 15% performance status >1 and 39%, 36%, 15%, 6% and 3% had 0, 1, 2, 3 and 4+ extranodal sites of involvement, respectively. 79% received no specific CNS-directed prophylaxis; 8% received intrathecal chemotherapy alone, 5% received systemic high-dose anti-metabolites and 8% received both intrathecal and systemic. After a median follow-up of 41 (interquartile range 28-61) months, 62 (4%) patients developed CNS relapse at a median of 9 (range 4-78) months from initial diagnosis. The 3-y incidence of CNS relapse, unadjusted and adjusted hazard ratios for CNS relapse according to number of extranodal sites of involvement are presented in Table 1. The competing risk regression analysis for CNS relapse using absolute number of extranodal sites of involvement is displayed in Figure 1; >2 vs 2 or fewer extranodal sites was associated with markedly increased risk of CNS progression (P<0.0001). Conclusions

In patients with newly diagnosed DLBCL staged with PET-CT and treated with R-CHOP, the presence of 3 or more extranodal sites of involvement is associated with markedly increased CNS relapse risk, even when adjusting for other variables. This finding may reflect the greater sensitivity of PET-CT for detection of extranodal disease compared with CT alone. This population would be suitable for prospective studies evaluating the efficacy of prophylaxis strategies and predictive biomarker studies.

 
Number of extranodal sites n (%) 3-year incidence % (95%CI) Unadjusted hazard ratio HR (95% CI) Adjusted hazard ratio* HR (95% CI)
0 602 (39) 1.7 (0.9-3.5) 1.0 (ref) 1.0 (ref)
1 559 (36) 4.0 (2.5-6.4) 3.0 (1.3-6.7) 3.1 (1.3-7.2)
2 230 (15) 4.8 (2.4-9.4) 3.4 (1.3-8.5) 2.8 (1.0-7.5)
3 92 (6) 12.8 (6.6-24.0) 8.1 (3.1-20.9) 6.3 (2.2-17.6)
4+ 53 (3) 32.1 (20.1-48.8) 22.0 (9.0-53.6) 17.2 (6.5-45.8)
Table 1: Risk of CNS relapse according to number of extranodal sites at initial diagnosis. *adjusted for LDH, age>60 y and performance status >1

Figure 1. Competing risk regression analysis depicting cumulative incidence of CNS relapse according to absolute number of extranodal sites of involvement.

 

Disclosures: Hutchings: Takeda: Research Funding . Connors: Roche: Research Funding ; Seattle Genetics: Research Funding . Seymour: Takeda: Honoraria , Membership on an entity’s Board of Directors or advisory committees ; Janssen: Honoraria , Membership on an entity’s Board of Directors or advisory committees , Research Funding ; Phebra: Consultancy , Honoraria , Membership on an entity’s Board of Directors or advisory committees ; Incyte: Honoraria , Membership on an entity’s Board of Directors or advisory committees ; Gilead: Honoraria , Membership on an entity’s Board of Directors or advisory committees ; AbbVie: Consultancy , Honoraria , Membership on an entity’s Board of Directors or advisory committees , Other: Travel support , Research Funding , Speakers Bureau ; Celgene: Consultancy , Honoraria , Membership on an entity’s Board of Directors or advisory committees , Other: Travel support , Speakers Bureau ; Genentech, Inc.: Membership on an entity’s Board of Directors or advisory committees ; Infinity: Honoraria , Membership on an entity’s Board of Directors or advisory committees ; Roche: Consultancy , Honoraria , Membership on an entity’s Board of Directors or advisory committees , Other: Travel support , Research Funding . Villa: Roche: Research Funding .

*signifies non-member of ASH