Copy number and transcriptome alterations associated with metastatic lesion response to treatment in colorectal cancer.

BACKGROUND: Therapeutic resistance is the main cause of death in metastatic colorectal cancer. To investigate genomic plasticity, most specifically of metastatic lesions, associated with response to first-line systemic therapy, we collected longitudinal liver metastatic samples and characterized the copy number aberration (CNA) landscape and its effect on the transcriptome. METHODS: Liver metastatic biopsies were collected prior to treatment (pre, n = 97) and when clinical imaging demonstrated therapeutic resistance (post, n = 43). CNAs were inferred from whole exome sequencing and were correlated with both the status of the lesion and overall patient progression-free survival (PFS). We used RNA sequencing data from the same sample set to validate aberrations as well as independent datasets to prioritize candidate genes. RESULTS: We identified a significantly increased frequency gain of a unique CN, in liver metastatic lesions after first-line treatment, on chr18p11.32 harboring 10 genes, including TYMS, which has not been reported in primary tumors (GISTIC method and test of equal proportions, FDR-adjusted p = 0.0023). CNA lesion profiles exhibiting different treatment responses were compared and we detected focal genomic divergences in post-treatment resistant lesions but not in responder lesions (two-tailed Fisher's Exact test, unadjusted p ≤ 0.005). The importance of examining metastatic lesions is highlighted by the fact that 15 out of 18 independently validated CNA regions found to be associated with PFS in this study were only identified in the metastatic lesions and not in the primary tumors. CONCLUSION: This investigation of genomic-phenotype associations in a large colorectal cancer liver metastases cohort identified novel molecular features associated with treatment response, supporting the clinical importance of collecting metastatic samples in a defined clinical setting.

Genetic Landscapes of Relapsed and Refractory Diffuse Large B-Cell Lymphomas.

PURPOSE: Relapsed or refractory diffuse large B-cell lymphoma (rrDLBCL) is fatal in 90% of patients, and yet little is known about its biology. EXPERIMENTAL DESIGN: Using exome sequencing, we characterized the mutation profiles of 38 rrDLBCL biopsies obtained at the time of progression after immunochemotherapy. To identify genes that may be associated with relapse, we compared the mutation frequency in samples obtained at relapse to an unrelated cohort of 138 diagnostic DLBCLs and separately amplified specific mutations in their matched diagnostic samples to identify clonal expansions. RESULTS: On the basis of a higher frequency at relapse and evidence for clonal selection, TP53, FOXO1, MLL3 (KMT2C), CCND3, NFKBIZ, and STAT6 emerged as top candidate genes implicated in therapeutic resistance. We observed individual examples of clonal expansions affecting genes whose mutations had not been previously associated with DLBCL including two regulators of NF-κB: NFKBIE and NFKBIZ We detected mutations that may be affect sensitivity to novel therapeutics, such as MYD88 and CD79B mutations, in 31% and 23% of patients with activated B-cell-type of rrDLBCL, respectively. We also identified recurrent STAT6 mutations affecting D419 in 36% of patients with the germinal center B (GCB) cell rrDLBCL. These were associated with activated JAK/STAT signaling, increased phospho-STAT6 protein expression and increased expression of STAT6 target genes. CONCLUSIONS: This work improves our understanding of therapeutic resistance in rrDLBCL and has identified novel therapeutic opportunities especially for the high-risk patients with GCB-type rrDLBCL. Clin Cancer Res; 22(9); 2290-300. ©2015 AACR.

Methods for sample acquisition and processing of serial blood and tumor biopsies for multicenter diffuse large B-cell lymphoma clinical trials.

Increasingly, targeted therapies are being developed to treat malignancies. To define targets, determine mechanisms of response and resistance, and develop biomarkers for the successful investigation of novel therapeutics, high-quality tumor biospecimens are critical. We have developed standard operating procedures (SOPs) to acquire and process serial blood and tumor biopsies from patients with diffuse large B-cell lymphoma enrolled in multicenter clinical trials. These SOPs allow for collection and processing of materials suitable for multiple downstream applications, including immunohistochemistry, cDNA microarrays, exome sequencing, and metabolomics. By standardizing these methods, we control preanalytic variables that ensure high reproducibility of results and facilitate the integration of datasets from such trials. This will facilitate translational research, better treatment selection, and more rapid and efficient development of new drugs. See all the articles in this CEBP Focus section, "Biomarkers, Biospecimens, and New Technologies in Molecular Epidemiology."

Next-generation biobanking of metastases to enable multidimensional molecular profiling in personalized medicine.

Great advances in analytical technology coupled with accelerated new drug development and growing understanding of biological challenges, such as tumor heterogeneity, have required a change in the focus for biobanking. Most current banks contain samples of primary tumors, but linking molecular signatures to therapeutic questions requires serial biopsies in the setting of metastatic disease, next-generation of biobanking. Furthermore, an integration of multidimensional analysis of various molecular components, that is, RNA, DNA, methylome, microRNAome and post-translational modifications of the proteome, is necessary for a comprehensive view of a tumor's biology. While data using such biopsies are now regularly presented, the preanalytical variables in tissue procurement and processing in multicenter studies are seldom detailed and therefore are difficult to duplicate or standardize across sites and across studies. In the context of a biopsy-driven clinical trial, we generated a detailed protocol that includes morphological evaluation and isolation of high-quality nucleic acids from small needle core biopsies obtained from liver metastases. The protocol supports stable shipping of samples to a central laboratory, where biopsies are subsequently embedded in support media. Designated pathologists must evaluate all biopsies for tumor content and macrodissection can be performed if necessary to meet our criteria of >60% neoplastic cells and <20% necrosis for genomic isolation. We validated our protocol in 40 patients who participated in a biopsy-driven study of therapeutic resistance in metastatic colorectal cancer. To ensure that our protocol was compatible with multiplex discovery platforms and that no component of the processing interfered with downstream enzymatic reactions, we performed array comparative genomic hybridization, methylation profiling, microRNA profiling, splicing variant analysis and gene expression profiling using genomic material isolated from liver biopsy cores. Our standard operating procedures for next-generation biobanking can be applied widely in multiple settings, including multicentered and international biopsy-driven trials.

Percutaneous US-guided renal biopsy: a retrospective study comparing the 16-gauge end-cut and 14-gauge side-notch needles.

PURPOSE: Assess glomerular yield and safety profile of two different types of needles for percutaneous ultrasound-guided kidney biopsy. MATERIALS AND METHODS: Over 24 months, 121 ultrasonographic ultrasound-guided renal biopsies were performed on native kidneys of 121 adults: 66 with 16-gauge, 29-mm end-cut (BioPince) needles and 55 with 14-gauge, 1.9-mm side-notch (Tru-Cut) needles. RESULTS: The mean number of complete glomeruli harvested per biopsy was 21.0 and 19.3, respectively, and the mean number of core samples required to obtain a satisfactory biopsy was 1.8 and 2.6, respectively. The ratio of glomeruli harvested to core samples needed with the end-cut needle was 58% greater than that with the side-notch needles (11.7 vs 7.4, respectively; difference of 4.3; 95% confidence interval: 2.0, 6.8). Procedures performed with end-cut needles were associated with fewer major complications (1.5% vs 7.3% with side-notch needles). CONCLUSIONS: Compared to the 14-g Tru-cut needle, the 16-g end-cut needle provided better glomerular yield per core sample, required fewer cores for satisfactory tissue specimen, and resulted in fewer major complications.

Recurrent obscure gastrointestinal bleeding: dilemmas and success with pharmacological therapies. Case series and review.

The present article describes three difficult cases of recurrent bleeding from obscure causes, followed by a review of the pitfalls and pharmacological management of obscure gastrointestinal bleeding. All three patients underwent multiple investigations. An intervening complicating diagnosis or antiplatelet drugs may have compounded longterm bleeding in two of the cases. A bleeding angiodysplasia was confirmed in one case but was aggravated by the need for anticoagulation. After multiple transfusions and several attempts at endoscopic management in some cases, long-acting octreotide was associated with decreased transfusion requirements and increased hemoglobin levels in all three cases, although other factors may have contributed in some. In the third case, however, the addition of low-dose thalidomide stopped bleeding for a period of at least 23 months.