627. Aggressive Lymphoma (Diffuse Large B-Cell & Other Aggressive B-Cell NHL)-Results from Retrospective/Observational Studies: PET-Guided Therapy & Prognostic Models in DLBCL


Long-Term Results of PET-Guided Radiation Therapy in Patients with Advanced-Stage Diffuse Large B-Cell Lymphoma Treated with R-CHOP in British Columbia

Ciara Louise Freeman, et al.

The authors of the study conclude:

This population-based analysis with long-term follow-up confirms that using a PET-directed approach to guide the use of XRT can spare pts from potential adverse effects of XRT without compromising outcome. The outcome of pts with PET-negative disease is comparable with previously published series and not significantly different from those with PET-pos disease who were treated with XRT. Among pts with bulky disease at diagnosis, almost 60% can be safely spared XRT.



Baseline PET-Derived Metabolic Tumor Volume Metrics Predict Progression-Free and Overall Survival in DLBCL after First-Line Treatment: Results from the Phase 3 GOYA Study

Lale Kostakoglu et al.

The authors of the study conclude:

This large prospective study confirms baseline TMTV and TLG as predictors of PFS and OS in DLBCL after first-line immunochemotherapy, while SUVmax may not be a predictor. Furthermore, TMTV and TLG appear to be better predictors of survival for pts with the unclassified and ABC subtypes of DLBCL than for those pts with the GCB subtype. Further analyses are underway comparing these results with the predictive value of percentage change from baseline to EOT PET, Deauville score-based analysis of EOT PET, and the various molecular DLBCL subtypes.



The T-Cell Receptor Repertoire Predicts Interim-PET in Patients with DLBCL Treated with R-CHOP: An Observational Study from a Prospective Clinical Trial

Mohamed Shanavas, et al.

The authors of the study conclude:

These findings demonstrate that the intratumoral TCR repertoire, and sequential blood sampling provide important information on outcome in DLBCL treated with RCHOP. A highly clonal T-cell repertoire in the TME was associated with iPET positivity after 4 cycles of R-CHOP. In line with findings in solid cancers treated with checkpoint blockade, development of clonal responses in peripheral blood was associated with iPET negativity. These findings indicate that clones expanded during therapy may be important in tumor clearance but that highly clonal T-cell responses in the tumor at diagnosis may hinder expansion of other T-cell responses to neoantigens. The circulating TCR composition is representative of the TME. These findings will assist the rationale design and therapeutic monitoring of novel immuno-therapeutic strategies.



Development of a Dynamic Model for Personalized Risk Assessment in Large B-Cell Lymphoma

David M. Kurtz, et al.

The authors of the study conclude:

Baseline and interim ctDNA measurements have prognostic significance in aggressive lymphomas. Integration of serial ctDNA measurements through a continuous, dynamic risk model can identify personalized outcome probabilities, yielding superior risk estimates. Dynamic risk assessment is potentially widely applicable and could guide future personalized therapeutic approaches.



Evaluation of the MD Anderson Tumor Score and Their Tumor Related Prognostic Variables in the Rituximab Era

Antonio Gutierrez, et al.

The authors of the study conclude:

1) All variables included in the original MD. Anderson TS retain an independent prognostic role in the rituximab era, including B symptoms, B2M and bulky mass; 2) TS remains predictive of FFS and OS in the rituximab era with a similar CPE in discrimination when compared to previously reported prognostic scores; 3) TS and GELTAMO-IPI showed a better identification of patients with high risk prognosis compared to IPI or NCCN-IPI; 4) R-IPI and R-TS may be combined in order to easily improve risk classification of DLBCL patients; 5) Further categorization of LDH, B2M and AA stage increased the ability of TS to identify high risk subsets of DLBCL; 6) TS could be a backbone for introducing other new molecular or biologic tumor related prognostic factors.



Diffuse Large B-Cell Lymphomas Transformed from or with Concurrent Follicular Lymphoma Demonstrate Similar Clinical Outcomes As De-Novo Diffuse Large B-Cell Lymphomas, Except for Cases Harboring Double Hit Rearrangements

Amir Behdad,  et al.

The authors of the study conclude:

DLBCLs transformed from FL or with concurrent diagnosis of FL (composite lymphoma) demonstrated similar clinical outcomes in our study. However, dual rearrangements are more prevalent in these patients and drive inferior survival similar to DH status in de novo DLBCL.