Next-generation sequencing (NGS) genomic oncology profiling assays have emerged as key drivers of personalized cancer care and translational research. However, validation of these assays to meet strict clinical standards has been historically problematic because of both significant assay complexity and a scarcity of optimal validation samples. Herein, we present the clinical validation of 76 genes from a novel 1212-gene large-scale hybrid capture cancer sequencing assay (University of Chicago Medicine OncoPlus) using full-data comparisons against multiple clinical NGS amplicon-based assays to yield dramatic increases in per-sample data comparison efficiency compared with previously published validations. Using a sample set of 104 normal, solid tumor, and hematopoietic malignancy specimens, head-to-head NGS data analyses allowed for 6.8 million individual clinical base call comparisons, including 2729 previously confirmed variants, with 100% sensitivity and specificity. University of Chicago Medicine OncoPlus showed excellent performance for detection of single-nucleotide variants, insertions/deletions up to 52 bp, and FLT3 internal tandem duplications of up to 102 bp or larger. Highly concordant copy number variant and ALK/RET/ROS1 gene fusion detection were also observed. In addition to underlining the efficiency of NGS validation via full-data benchmarking against existing clinical NGS assays, this study also highlights the degree of performance similarity between hybrid capture and amplicon assays that is attainable with the application of strict quality control parameters and optimized computational analytics.

Ibrutinib (ibr), a first-in-class Bruton tyrosine kinase (BTK) inhibitor, has demonstrated high response rates in both relapsed/refractory and treatment naïve chronic lymphocytic leukemia (CLL). However, about 25% of patients discontinue ibrutinib therapy at a median follow-up of 20 months and many patients discontinue the treatment due to leukemia progression or Richter transformation. Mutations affecting the C481 residue of BTK disrupt ibrutinib binding and have been characterized by us and others as the most common mechanism of ibrutinib resistance. Thus far, all described BTK mutations are located in its kinase domain and mutations outside this domain have never been described. Herein, we report a patient whose CLL progressed, was salvaged with ibrutinib and then relapsed. Serial analysis of samples throughout patient's clinical course identified a structurally novel mutation (BTKT316A) in the SH2 domain, but not kinase domain, of Bruton tyrosine kinase which was associated with disease relapse. Functionally, cells carrying BTKT316A show resistance to ibrutinib at both cellular and molecular levels to a similar extent as BTKC481S. Our study lends further insight into the diverse mechanisms of ibrutinib resistance that has important implications for the development of next-generation BTK inhibitors as well as mutation detection in relapsed patients.

clinicaltrials.gov Identifier: NCT00045032.

Amplicon-based targeted next-generation sequencing assays are used widely to test for clinically relevant somatic mutations in cancer. However, accurate detection of large insertions and deletions (indels) via these assays remains challenging. Sequencing reads that cover these anomalies are, by definition, different from the reference sequence, and lead to variable performance of alignment algorithms. Reads with large indels may be aligned incorrectly, causing incorrect calls, or may remain unmapped and essentially ignored by downstream informatics pipeline sub-processes. Herein, we describe Amplicon Indel Hunter (AIH), a novel large (>5-bp) indel detection method that is reference genome independent and highly sensitive for the identification of somatic indels in amplicon-based, paired-end, next-generation sequencing data. We validated the algorithm for sensitivity and specificity using a set of clinical cancer samples with Clinical Laboratory Improvement Amendment-confirmed indels as well as in silico mutated data sets. The AIH detected 100% of tested large indels with relatively higher mutant allele frequencies compared with a variety of traditional aligners, which showed variably reduced sensitivity and specificity by comparison. The AIH especially outperformed alignment-based methods for detection of all tested FLT3 internal tandem duplications up to 102 bp. Because AIH runs in parallel to traditional alignment-based informatics pathways, it can be readily incorporated into nearly any analysis pipeline for somatic mutation detection in paired-end amplicon-based data.

- The morphologic similarity and RAS mutations in FAs, NIFTPs, and IE-PTC-FVs supports the genetic similarity of those follicular neoplasms in contrast to the unique presence of BRAF V600E mutations in PTC-EFGs. Using strict diagnostic criteria supported by molecular testing, tumors with extensive follicular growth can be classified into follicular type or RAS-like (FA, NIFTP, IE-PTC-FV) versus papillary type or BRAF V600E-like (PTC-EFG).

Purpose Identification of single-gene biomarkers that are prognostic of outcome can shed new insights on the molecular mechanisms that drive breast cancer and other cancers. Methods Exploratory analysis of 20,464 single-gene messenger RNAs (mRNAs) in the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) discovery cohort indicates that low expression of FGD3 mRNA is prognostic for poor outcome. Prognostic significance of faciogenital dysplasia 3 (FGD3), SUSD3, and other single-gene proliferation markers was evaluated in breast cancer and The Cancer Genome Atlas (TCGA) cohorts. Results A meta-analysis of Cox regression of FGD3 mRNA as a continuous variable for overall survival of estrogen receptor (ER)–positive samples in METABRIC discovery, METABRIC validation, TCGA breast cancer, and Combination Chemotherapy in Treating Women With Breast Cancer (E2197) cohorts resulted in a combined hazard ratio (HR) of 0.69 (95% CI, 0.63 to 0.75), indicating better outcome with high expression. In the ER-negative samples, the combined meta-analysis HR was 0.72 (95% CI, 0.63 to 0.82), suggesting that FGD3 is prognostic regardless of ER status. The potential of FGD3 as a biomarker for freedom from recurrence was evaluated in the Breast International Group 1-98 (BIG 1-98; Letrozole or Tamoxifen in Treating Postmenopausal Women With Breast Cancer) study (HR, 0.85; 95% CI, 0.76 to 0.93) for breast cancer–free interval. In the Hungarian Academy of Science (HAS) breast cancer cohort, splitting on the median had an HR of 0.49 (95% CI, 0.42 to 0.58) for recurrence-free survival. A comparison of the Stouffer P value in five ER-positive cohorts showed that FGD3 ( P = 3.8E-14) outperformed MKI67 ( P = 1.06E-8) and AURKA ( P = 2.61E-5). A comparison of the Stouffer P value in four ER-negative cohorts showed that FGD3 ( P = 3.88E-5) outperformed MKI67 ( P = .477) and AURKA ( P = .820). Conclusion FGD3 was previously shown to inhibit cell migration. FGD3 mRNA is regulated by ESR1 and is associated with favorable outcome in six distinct breast cancer cohorts and four TCGA cancer cohorts. This suggests that FGD3 is an important clinical biomarker.

To determine whether CYP19A1 polymorphisms are associated with abnormal activity of aromatase and with musculoskeletal and bone side effects of aromatase inhibitors. DNA was isolated from tumor specimens of 4861 postmenopausal women with hormone receptor-positive breast cancer enrolled in the BIG 1–98 trial to receive tamoxifen and/or letrozole for 5 years. Tumors were genotyped for six CYP19A1 polymorphisms using PCR-based methods. Associations with breast cancer-free interval (BCFI), distant recurrence-free interval (DRFI), musculoskeletal and bone adverse events (AEs) were assessed using Cox proportional hazards models. All statistical tests were two-sided. No association between the CYP19A1 genotypes and BCFI or DRFI was observed overall. A reduced risk of a breast cancer event for tamoxifen-treated patients with rs700518 variants was observed (BCFI CC/TC vs. TT: HR 0.53, 95 % CI 0.34–0.82, interaction P = 0.08), but not observed for letrozole-treated patients. There was an increased risk of musculoskeletal AEs for patients with rs700518 variants CC/TC versus TT (HR 1.22, 95 % CI 1.03–1.45, P = 0.02), regardless of treatment. Tamoxifen-treated patients with rs4646 variants had a reduced risk of bone AEs (AA/CA vs. CC: HR 0.76, 95 % CI 0.59–0.98), whereas an increase of minor allele (C) of rs10046 was associated with an increased risk of bone AEs (HR 1.28, 95 % CI 1.07–1.52). rs936308 variants were associated with a reduced risk of bone AEs in letrozole-treated patients (GG/GC vs. CC: HR 0.73, 95 % CI 0.54–0.99), different from in tamoxifen-treated patients (GG/GC vs. CC: HR 1.32, 95 % CI 0.92–1.90, interaction P = 0.01). CYP19A1 rs700518 variants showed associations with BCFI, DRFI, in tamoxifen treated patients and musculoskeletal AEs regardless of treatment. SNPs rs4646, rs10046, and rs936308 were associated with bone AEs.

There is a high prevalence of nuclear MiTF expression in UPSs (89%) and AFXs (80%). Rare UPSs showed non-specific nuclear HMB45 or S100 staining. These findings argue against using MiTF in isolation to differentiate between UPS or AFX and melanoma, and caution in interpreting focal staining for a single additional melanocytic marker. Casein block may eliminate non-specific staining. MiTF should be used to support a diagnosis of melanoma only if multiple melanocytic markers are positive.