International Working Group consensus response evaluation criteria in lymphoma (RECIL 2017)

In recent years, the number of approved and investigational agents that can be safely administered for the treatment of lymphoma patients for a prolonged period of time has substantially increased. Many of these novel agents are evaluated in early-phase clinical trials in patients with a wide range of malignancies, including solid tumors and lymphoma. Furthermore, with the advances in genome sequencing, new "basket" clinical trial designs have emerged that select patients based on the presence of specific genetic alterations across different types of solid tumors and lymphoma. The standard response criteria currently in use for lymphoma are the Lugano Criteria which are based on [18F]2-fluoro-2-deoxy-D-glucose positron emission tomography or bidimensional tumor measurements on computerized tomography scans. These differ from the RECIST criteria used in solid tumors, which use unidimensional measurements. The RECIL group hypothesized that single-dimension measurement could be used to assess response to therapy in lymphoma patients, producing results similar to the standard criteria. We tested this hypothesis by analyzing 47 828 imaging measurements from 2983 individual adult and pediatric lymphoma patients enrolled on 10 multicenter clinical trials and developed new lymphoma response criteria (RECIL 2017). We demonstrate that assessment of tumor burden in lymphoma clinical trials can use the sum of longest diameters of a maximum of three target lesions. Furthermore, we introduced a new provisional category of a minor response. We also clarified response assessment in patients receiving novel immune therapy and targeted agents that generate unique imaging situations.

An integrated genomic analysis of lung cancer reveals loss of DUSP4 in EGFR-mutant tumors

To address the biological heterogeneity of lung cancer, we studied 199 lung adenocarcinomas by integrating genome-wide data on copy number alterations and gene expression with full annotation for major known somatic mutations in this cancer. This revealed non-random patterns of copy number alterations significantly linked to EGFR and KRAS mutation status and to distinct clinical outcomes, and led to the discovery of a striking association of EGFR mutations with under-expression of DUSP4, a gene within a broad region of frequent single-copy loss on 8p. DUSP4 is involved in negative feedback control of EGFR signaling and we provide functional validation for its role as a growth suppressor in EGFR-mutant lung adenocarcinoma. DUSP4 loss also associates with p16/CDKN2A deletion and defines a distinct clinical subset of lung cancer patients. Another novel observation is that of reciprocal relationship between EGFR and LKB1 mutations. These results highlight the power of integrated genomics to identify candidate driver genes within recurrent broad regions of copy number alteration and to delineate distinct oncogenetic pathways in genetically complex common epithelial cancers.

Evaluation of the potential of histone deacetylase inhibitors to synergize the antineoplastic effects of the proteasome inhibitor bortezomib in mantle cell lymphoma (MCL)

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Background: Romidepsin (R) and belinostat (B) are inhibitors of histone deacetylases (HDACI). HDACIs are known to induce cell death in malignant cells through multiple mechanisms, including up-regulation of death receptors, disruption of Hsp90 function and generation of reactive oxygen species. Mantle cell lymphoma is an aggressive subtype of non-Hodgkin lymphoma characterized by the reciprocal translocation t(11;14)(q13;q32) leading to the overexpression of cyclin D1. Methods: We investigated the cytotoxicity of romidepsin and belinostat alone and in combination with the proteasome inhibitor bortezomib in cell lines of mantle cell lymphoma (HBL2, Granta519, Jeko1). Cell Titer-Glo assay followed by luminometric acquisition was used for all cytotoxicity assays. Drug:drug interactions in terms of synergism, additivity or antagonism were computed using the Relative Risk Ratio Analysis (RRR, GraphPad software) with a RRR < 1 defining synergism, RRR=1 additivity and RRR>1 antagonism. Results: The IC50 values for R and B alone at 24 hours were: HBL-2: R=4.7nM, B=490nM; Jeko-1: R=3nM, B=750nM; Granta519: R=45nM, B=30,700nM. As single agent, romidepsin was about 100 fold more potent than belinostat. The combination of belinostat (100–1000nM) or romidepsin (1–40nM) with bortezomib (3–4nM) showed synergism in all cell lines at different concentrations. For romidepsin plus bortezomib, RRR in Granta519=0.05–0.14, RRR in Jeko1=0.1–0.75, RRR in HBL2=0.03–0.81. For belinostat plus bortezomib, RRR in Granta519= 0.07–0.38, RRR in Jeko1=0.16–0.49, RRR in HBL2=0.04–0.69. Flowcytometry for apoptosis, cell cycle analysis and mitochondrial membrane potential as well as immunoblottings for hystone H3 acetylation, cyclin D1, Bcl-XL, Mcl-1, BIM and IKB-α suggest this strategy may modulate cyclin D1 and p27 in MCL which is known to be grossly deregulated for these proteins. Conclusions: In this analysis, while romidepsin had improved single agent activity, when combined with bortezomib both HDACI showed potent synergism.

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