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DNA-FISH analysis of non-EGFR-amplified GBM CTCs.

Immunohistologic and DNA-FISH analysis of tumor cells and CTCs from a patient with metastatic GBM.

Methods and Supplementary Figure Legends

STEAM cocktail staining specifically identifies GBM cells.

Clinical association of CTC frequency

Unsupervised hierarchical clustering analysis of patient and xenograft single cell qRT-PCR expression data.

GBM8 and GBM24 growth in culture.

Tumor genotypes and CTC frequency

PDF file - 8K, Table S1. TERT promoter mutation status in 59 pTa and 17 carcinoma in situ (CIS) patients.

Noninvasive approaches for early detection of bladder cancer are actively being investigated. We recently developed a urine- based molecular assay for the detection and surveillance of bladder neoplasms (UroSEEK). UroSEEK is designed to detect alterations in 11 genes that include most common genetic alterations in bladder cancer. In this study, we analyzed 527 cases, including 373 noninvasive and 154 invasive urothelial carcinomas of bladder from transurethral resections or cystectomies performed at four institutions (1991–2016). Two different mutational analysis assays of a representative tumor area were performed: first, a singleplex PCR assay for evaluation of the TERT promoter region (TERTSeqS) and second, a multiplex PCR assay using primers designed to amplify regions of interest of 10 (FGFR3, PIK3CA, TP53, HRAS, KRAS, ERBB2, CDKN2A, MET, MLL, and VHL) genes (UroSeqS). Overall, 92% of all bladder tumors were positive for at least one genetic alteration in the UroSEEK panel. We found TERT promoter mutations in 77% of low-grade noninvasive papillary carcinomas, with a relatively lower incidence of 65% in high-grade noninvasive papillary carcinomas and carcinomas in situ; p = 0.017. Seventy-two percent of pT1 and 63% of muscle-invasive bladder tumors harbored TERT promoter mutations with g.1295228C>T alteration being the most common in all groups. FGFR3 and PIK3CA mutations were more frequent in low-grade noninvasive papillary carcinomas compared with high-grade noninvasive papillary carcinomas and carcinomas in situ (p

Aneuploidy is a feature of most cancer cells, and a myriad of approaches have been developed to detect it in clinical samples. We previously described primers that could be used to amplify ∼38,000 unique long interspersed nucleotide elements (LINEs) from throughout the genome. Here we have developed an approach to evaluate the sequencing data obtained from these amplicons. This approach, called Within-Sample AneupLoidy DetectiOn (WALDO), employs supervised machine learning to detect the small changes in multiple chromosome arms that are often present in cancers. We used WALDO to search for chromosome arm gains and losses in 1,677 tumors and in 1,522 liquid biopsies of blood from cancer patients or normal individuals. Aneuploidy was detected in 95% of cancer biopsies and in 22% of liquid biopsies. Using single-nucleotide polymorphisms within the amplified LINEs, WALDO concomitantly assesses allelic imbalances, microsatellite instability, and sample identification. WALDO can be used on samples containing only a few nanograms of DNA and as little as 1% neoplastic content and has a variety of applications in cancer diagnostics and forensic science.

Anelloviruses are a ubiquitous component of healthy human viromes and remain highly prevalent after being acquired early in life. The full extent of "anellome" diversity and its evolutionary dynamics remain unexplored. We employed in-depth sequencing of blood-transfusion donor(s)-recipient pairs coupled with public genomic resources for a large-scale assembly of anellovirus genomes and used the data to characterize global and personal anellovirus diversity through time. The breadth of the anellome is much greater than previously appreciated, and individuals harbor unique anellomes and transmit lineages that can persist for several months within a diverse milieu of endemic host lineages. Anellovirus sequence diversity is shaped by extensive recombination at all levels of divergence, hindering traditional phylogenetic analyses. Our findings illuminate the transmission dynamics and vast diversity of anelloviruses and set the foundation for future studies to characterize their biology.

Our group and others have previously demonstrated the presence of TERT promoter mutations (TERT-mut) in 60–80% of urothelial carcinomas and some of their histologic variants. Five other genes have been frequently implicated in bladder cancer: FGRF3, TP53, PIK3CA, HRAS, and CDKN2A. In the current study, we sought to determine the prevalence of mutations in TERT and these five other genes in de novo papillary urothelial neoplasms of low malignant potential (PUNLMP) of the urinary bladder. A retrospective search of our archives for PUNLMP was performed and 30 de novo cases were identified and included in the study. We found mutations in TERT (TERT-mut) and FGFR3 (FGFR3-mut) to be the most common alterations in the cohort (63 and 60%, respectively). The majority of the TERT-mut-positive tumors (84%) had a g.1295228C > T alteration with the remaining tumors demonstrating g.1295250C > T. Approximately one fourth of tumors had TP53 mutations. These findings support the potential utility of a uniform genetic mutation panel to detect bladder cancers of various subtypes.

Urine cytology is an essential element of the diagnostic work up of hematuria. A significant proportion of cases continue to be placed in the “atypical” or “suspicious” categories of the Paris system for urine cytology, posing difficulty in patient management. We report on the performance of our recently described urine-based assay “UroSEEK” in cases with equivocal diagnosis in patients who are investigated for bladder cancer. Urine samples were collected from two cohorts. The first consisted of patients who presented with hematuria or lower urinary tract symptoms (early detection cohort) and the second of patients that are in follow-up for prior bladder cancer (surveillance cohort). Urine samples were analyzed for mutations in 11 genes and aneuploidy. In the early detection setting, we found high sensitivity and specificity (96% and 88%, respectively) and a strong negative predictive value of 99%. The assay performance was less robust in the surveillance cohort (sensitivity of 74%, specificity of 72%, and negative predictive value of 53%). UroSEEK demonstrated a notable lead time to cancer diagnosis. Seven cases in the early detection cohort and 71 surveillance cases were detected at least 6 months prior to clinical diagnosis. Our results suggest a potential role for UroSEEK assay in guiding management of patients with atypical urine cytology if confirmed in future prospective trials.

Pancreatic cysts are common and often pose a management dilemma, because some cysts are precancerous, whereas others have little risk of developing into invasive cancers. We used supervised machine learning techniques to develop a comprehensive test, CompCyst, to guide the management of patients with pancreatic cysts. The test is based on selected clinical features, imaging characteristics, and cyst fluid genetic and biochemical markers. Using data from 436 patients with pancreatic cysts, we trained CompCyst to classify patients as those who required surgery, those who should be routinely monitored, and those who did not require further surveillance. We then tested CompCyst in an independent cohort of 426 patients, with histopathology used as the gold standard. We found that clinical management informed by the CompCyst test was more accurate than the management dictated by conventional clinical and imaging criteria alone. Application of the CompCyst test would have spared surgery in more than half of the patients who underwent unnecessary resection of their cysts. CompCyst therefore has the potential to reduce the patient morbidity and economic costs associated with current standard-of-care pancreatic cyst management practices.

Somatic activating mutations in the promoter of the telomerase reverse transcriptase (TERT) gene are the most common genetic alterations in urothelial carcinoma (UC) of the bladder and upper urinary tract. Little is known, however, about TERT-mutation status in the relatively uncommon but clinically aggressive micropapillary (MPC) variant. We evaluated the presence of TERT promoter mutations in MPC of the bladder and upper urinary tract. A retrospective search of our archives for MPC and UC with micropapillary features (2005–2014) was performed. All slides were reviewed to confirm the histologic diagnosis. Thirty-three specimens from 31 patients had FFPE blocks available for DNA analysis and were included in the study. Intratumoral areas of non-micropapillary histology were also evaluated when present. Samples were analyzed with Safe-SeqS, a sequencing error reduction technology, and sequenced using the Illumina MiSeq platform. TERT promoter mutations were detected in all specimens with pure MPC (18 of 18) and UC with focal micropapillary features (15 of 15). Similar to conventional UC, the predominant mutations identified occurred at positions −124 (C228T) (85 %) and −146 (C250T) (12 %) bp upstream of the TERT ATG start site. In heterogeneous tumors with focal variant histology, intratumoral concordant mutations were found in variant (MPC and non-MPC) and corresponding conventional UC. We found TERT promoter mutations, commonly found in conventional UC, to be frequently present in MPC. Our finding of concordant intratumoral mutational alterations in cases with focal variant histology lends support to the common oncogenesis origin of UC and its variant histology.

TERT promoter mutations (TERT-mut) have been detected in 60% to 80% of urothelial carcinomas. A molecular urine-based screening assay for the detection of TERT-mut is currently being pursued by our group and others. A small but significant number of bladder carcinomas are adenocarcinoma. The current study assesses the incidence of TERT-mut in primary adenocarcinomas of urinary bladder. A retrospective search of our institutional pathology records identified 23 cystectomy specimens with a diagnosis of adenocarcinoma (2000–2014). All slides were reviewed by a senior urologic pathologist to confirm tumor type and select a representative formalin-fixed, paraffin-embedded block for mutational analysis. Adequate material for DNA testing was available in 14 cases (7 enteric type and 7 not otherwise specified). TERT-mut sequencing analysis was performed using previously described SafeSeq technique. Overall, 28.5% of primary adenocarcinoma harbored TERT-mut. Interestingly, 57% of nonenteric adenocarcinomas were mutation positive, whereas none of the enteric-type tumors harbored mutations. Similar to urothelial carcinoma, we found a relatively higher rate of TERT-mut among nonenteric-type adenocarcinomas further supporting the potential utility of TERT-mut urine-based screening assay for bladder cancer.

Current non-invasive approaches for detection of urothelial cancers are suboptimal. We developed a test to detect urothelial neoplasms using DNA recovered from cells shed into urine. UroSEEK incorporates massive parallel sequencing assays for mutations in 11 genes and copy number changes on 39 chromosome arms. In 570 patients at risk for bladder cancer (BC), UroSEEK was positive in 83% of those who developed BC. Combined with cytology, UroSEEK detected 95% of patients who developed BC. Of 56 patients with upper tract urothelial cancer, 75% tested positive by UroSEEK, including 79% of those with non-invasive tumors. UroSEEK detected genetic abnormalities in 68% of urines obtained from BC patients under surveillance who demonstrated clinical evidence of recurrence. The advantages of UroSEEK over cytology were evident in low-grade BCs; UroSEEK detected 67% of cases whereas cytology detected none. These results establish the foundation for a new non-invasive approach for detection of urothelial cancer.

Summary Activating mutations in the promoter of the telomerase reverse transcriptase (TERT) gene are the most common genetic alterations in urothelial carcinoma (UC) of the bladder and upper urinary tract. Although the cadherin 1 (CDH1) gene is commonly mutated in the clinically aggressive plasmacytoid variant of urothelial carcinoma (PUC), little is known about their TERT promoter mutation status. A retrospective search of our archives for PUC and UC with plasmacytoid and/or signet ring cell features (2007-2014) was performed. Ten specimens from 10 patients had archived material available for DNA analysis and were included in the study. Intratumoral areas of nonplasmacytoid histology were also evaluated when present. Samples were analyzed for TERT promoter mutations with Safe-SeqS, a sequencing error-reduction technology, and sequenced using a targeted panel of the 10 most commonly mutated genes in bladder cancer on the Illumina MiSeq platform. TERT promoter mutations were detected in specimens with pure and focal plasmacytoid features (6/10). Similar to conventional UC, the predominant mutation identified was g.1295228C>T. In heterogeneous tumors with focal variant histology, concordant mutations were found in plasmacytoid and corresponding conventional, glandular, or sarcomatoid areas. Co-occurring mutations in tumor protein p53 (TP53, 2 cases) and kirsten rat sarcoma (KRAS) viral proto-oncogene (1 case) were also detected. TERT promoter mutations are frequently present in PUC, which provides further evidence that TERT promoter mutations are common events in bladder cancer, regardless of histologic subtype, and supports their inclusion in any liquid biopsy assay for bladder cancer.

We report the detection of endometrial and ovarian cancers based on genetic analyses of DNA recovered from the fluids obtained during a routine Papanicolaou (Pap) test. The new test, called PapSEEK, incorporates assays for mutations in 18 genes as well as an assay for aneuploidy. In Pap brush samples from 382 endometrial cancer patients, 81% [95% confidence interval (CI), 77 to 85%] were positive, including 78% of patients with early-stage disease. The sensitivity in 245 ovarian cancer patients was 33% (95% CI, 27 to 39%), including 34% of patients with early-stage disease. In contrast, only 1.4% of 714 women without cancer had positive Pap brush samples (specificity, ~99%). Next, we showed that intrauterine sampling with a Tao brush increased the detection of malignancy over endocervical sampling with a Pap brush: 93% of 123 (95% CI, 87 to 97%) patients with endometrial cancer and 45% of 51 (95% CI, 31 to 60%) patients with ovarian cancer were positive, whereas none of the samples from 125 women without cancer were positive (specificity, 100%). Finally, in 83 ovarian cancer patients in whom plasma was available, circulating tumor DNA was found in 43% of patients (95% CI, 33 to 55%). When plasma and Pap brush samples were both tested, the sensitivity for ovarian cancer increased to 63% (95% CI, 51 to 73%). These results demonstrate the potential of mutation-based diagnostics to detect gynecologic cancers at a stage when they are more likely to be curable.

Current non-invasive approaches for detection of urothelial cancers are suboptimal. We developed a test to detect urothelial neoplasms using DNA recovered from cells shed into urine. UroSEEK incorporates massive parallel sequencing assays for mutations in 11 genes and copy number changes on 39 chromosome arms. In 570 patients at risk for bladder cancer (BC), UroSEEK was positive in 83% of those who developed BC. Combined with cytology, UroSEEK detected 95% of patients who developed BC. Of 56 patients with upper tract urothelial cancer, 75% tested positive by UroSEEK, including 79% of those with non-invasive tumors. UroSEEK detected genetic abnormalities in 68% of urines obtained from BC patients under surveillance who demonstrated clinical evidence of recurrence. The advantages of UroSEEK over cytology were evident in low-grade BCs; UroSEEK detected 67% of cases whereas cytology detected none. These results establish the foundation for a new non-invasive approach for detection of urothelial cancer.

Background & Aims The management of pancreatic cysts poses challenges to both patients and their physicians. We investigated whether a combination of molecular markers and clinical information could improve the classification of pancreatic cysts and management of patients. Methods We performed a multi-center, retrospective study of 130 patients with resected pancreatic cystic neoplasms (12 serous cystadenomas, 10 solid pseudopapillary neoplasms, 12 mucinous cystic neoplasms, and 96 intraductal papillary mucinous neoplasms). Cyst fluid was analyzed to identify subtle mutations in genes known to be mutated in pancreatic cysts ( BRAF , CDKN2A , CTNNB1 , GNAS , KRAS , NRAS , PIK3CA , RNF43 , SMAD4 , TP53 , and VHL ); to identify loss of heterozygozity at CDKN2A , RNF43 , SMAD4 , TP53 , and VHL tumor suppressor loci; and to identify aneuploidy. The analyses were performed using specialized technologies for implementing and interpreting massively parallel sequencing data acquisition. An algorithm was used to select markers that could classify cyst type and grade. The accuracy of the molecular markers was compared with that of clinical markers and a combination of molecular and clinical markers. Results We identified molecular markers and clinical features that classified cyst type with 90%−100% sensitivity and 92%−98% specificity. The molecular marker panel correctly identified 67 of the 74 patients who did not require surgery and could, therefore, reduce the number of unnecessary operations by 91%. Conclusions We identified a panel of molecular markers and clinical features that show promise for the accurate classification of cystic neoplasms of the pancreas and identification of cysts that require surgery.

Cell-free DNA shed by cancer cells has been shown to be a rich source of putative tumor-specific biomarkers. Because cell-free DNA from brain and spinal cord tumors cannot usually be detected in the blood, we studied whether the cerebrospinal fluid (CSF) that bathes the CNS is enriched for tumor DNA, here termed CSF-tDNA. We analyzed 35 primary CNS malignancies and found at least one mutation in each tumor using targeted or genome-wide sequencing. Using these patient-specific mutations as biomarkers, we identified detectable levels of CSF-tDNA in 74% [95% confidence interval (95% CI) = 57-88%] of cases. All medulloblastomas, ependymomas, and high-grade gliomas that abutted a CSF space were detectable (100% of 21 cases; 95% CI = 88-100%), whereas no CSF-tDNA was detected in patients whose tumors were not directly adjacent to a CSF reservoir (P0.0001, Fisher's exact test). These results suggest that CSF-tDNA could be useful for the management of patients with primary tumors of the brain or spinal cord.

Chromosomal amplifications are among the most common genetic alterations found in human cancers. However, experimental systems to study the processes that lead to specific, recurrent amplification events in human cancers are lacking. Moreover, some common amplifications, such as that at 8p11-12 in breast cancer, harbor multiple driver oncogenes, which are poorly modeled by conventional overexpression approaches. We sought to develop an experimental system to model recurrent chromosomal amplification events in human cell lines. Our strategy is to use homologous-recombination-mediated gene targeting to deliver a dominantly selectable, amplifiable marker to a specified chromosomal location. We used adeno-associated virus vectors to target human MCF-7 breast cancer cells at the ZNF703 locus, in the recurrent 8p11-12 amplicon, using the E. coli inosine monophosphate dehydrogenase (IMPDH) enzyme as a marker. We applied selective pressure using IMPDH inhibitors. Surviving clones were found to have increased copy number of ZNF703 (average 2.5-fold increase) by droplet digital PCR and FISH. Genome-wide array comparative genomic hybridization confirmed that amplifications had occurred on the short arm of chromosome 8, without changes on 8q or other chromosomes. Patterns of amplification were variable and similar to those seen in primary human breast cancers, including “sawtooth” patterns, distal copy number loss, and large continuous regions of copy number gain. This system will allow study of the cis- and trans-acting factors that are permissive for chromosomal amplification and provide a model to analyze oncogene cooperativity in amplifications harboring multiple candidate driver genes. Electronic supplementary material The online version of this article (doi:10.1007/s10549-015-3468-2) contains supplementary material, which is available to authorized users.

Current non-invasive approaches for bladder cancer (BC) detection are suboptimal. We report the development of non-invasive molecular test for BC using DNA recovered from cells shed into urine. This “UroSEEK” test incorporates assays for mutations in 11 genes and copy number changes on 39 chromosome arms. We first evaluated 570 urine samples from patients at risk for BC (microscopic hematuria or dysuria). UroSEEK was positive in 83% of patients that developed BC, but in only 7% of patients who did not develop BC. Combined with cytology, 95% of patients that developed BC were positive. We then evaluated 322 urine samples from patients soon after their BCs had been surgically resected. UroSEEK detected abnormalities in 66% of the urine samples from these patients, sometimes up to 4 years prior to clinical evidence of residual neoplasia, while cytology was positive in only 25% of such urine samples. The advantages of UroSEEK over cytology were particularly evident in low-grade tumors, wherein cytology detected none while UroSEEK detected 67% of 49 cases. These results establish the foundation for a new, non-invasive approach to the detection of BC in patients at risk for initial or recurrent disease.

Upper tract urothelial carcinomas (UTUC) of the renal pelvis or ureter can be difficult to detect and challenging to diagnose. Here, we report the development and application of a non-invasive test for UTUC based on molecular analyses of DNA recovered from cells shed into the urine. The test, called UroSEEK, incorporates assays for mutations in eleven genes frequently mutated in urologic malignancies and for allelic imbalances on 39 chromosome arms. At least one genetic abnormality was detected in 75% of urinary cell samples from 56 UTUC patients but in only 0.5% of 188 samples from healthy individuals. The assay was considerably more sensitive than urine cytology, the current standard-of-care. UroSEEK therefore has the potential to be used for screening or to aid in diagnosis in patients at increased risk for UTUC, such as those exposed to herbal remedies containing the carcinogen aristolochic acid.

The identification of mutations that are present at low frequencies in clinical samples is an essential component of precision medicine. The development of molecular barcoding for next-generation sequencing has greatly enhanced the sensitivity of detecting such mutations by massively parallel sequencing. However, further improvements in specificity would be useful for a variety of applications. We herein describe a technology (BiSeqS) that can increase the specificity of sequencing by at least two orders of magnitude over and above that achieved with molecular barcoding and can be applied to any massively parallel sequencing instrument. BiSeqS employs bisulfite treatment to distinguish the two strands of molecularly barcoded DNA; its specificity arises from the requirement for the same mutation to be identified in both strands. Because no library preparation is required, the technology permits very efficient use of the template DNA as well as sequence reads, which are nearly all confined to the amplicons of interest. Such efficiency is critical for clinical samples, such as plasma, in which only tiny amounts of DNA are often available. We show here that BiSeqS can be applied to evaluate transversions, as well as small insertions or deletions, and can reliably detect one mutation among >10,000 wild-type molecules.

Intraductal papillary mucinous neoplasms (IPMNs) are lesions that can progress to invasive pancreatic cancer and constitute an important system for studies of pancreatic tumorigenesis. We performed comprehensive genomic analyses of entire IPMNs to determine the diversity of somatic mutations in genes that promote tumorigenesis.We microdissected neoplastic tissues from 6-24 regions each of 20 resected IPMNs, resulting in 227 neoplastic samples that were analyzed by capture-based targeted sequencing. Somatic mutations in genes associated with pancreatic tumorigenesis were assessed across entire IPMN lesions, and the resulting data were supported by evolutionary modeling, whole-exome sequencing, and in situ detection of mutations.We found a high prevalence of heterogeneity among mutations in IPMNs. Heterogeneity in mutations in KRAS and GNAS was significantly more prevalent in IPMNs with low-grade dysplasia than in IPMNs with high-grade dysplasia (P.02). Whole-exome sequencing confirmed that IPMNs contained multiple independent clones, each with distinct mutations, as originally indicated by targeted sequencing and evolutionary modeling. We also found evidence for convergent evolution of mutations in RNF43 and TP53, which are acquired during later stages of tumorigenesis.In an analysis of the heterogeneity of mutations throughout IPMNs, we found that early-stage IPMNs contain multiple independent clones, each with distinct mutations, indicating their polyclonal origin. These findings challenge the model in which pancreatic neoplasms arise from a single clone. Increasing our understanding of the mechanisms of IPMN polyclonality could lead to strategies to identify patients at increased risk for pancreatic cancer.

We determined whether the mutations found in ovarian cancers could be identified in the patients' ovarian cyst fluids. Tumor-specific mutations were detectable in the cyst fluids of 19 of 23 (83%) borderline tumors, 10 of 13 (77%) type I cancers, and 18 of 18 (100%) type II cancers. In contrast, no mutations were found in the cyst fluids of 18 patients with benign tumors or non-neoplastic cysts. Though large, prospective studies are needed to demonstrate the safety and clinical utility of this approach, our results suggest that the genetic evaluation of cyst fluids might be able to inform the management of the large number of women with these lesions. DOI: http://dx.doi.org/10.7554/eLife.15175.001, eLife digest More than a third of women develop ovarian cysts during their lifetimes. The vast majority of these cysts are harmless, but a small number are caused by ovarian cancers. These cancers often produce no symptoms until the disease has spread throughout the abdomen or to other organs, so many women go undiagnosed until their chances of being successfully treated are low. Currently, there is no reliable way to determine whether an ovarian cyst is cancerous without performing surgery. As a result, many women undergo unnecessary, invasive surgeries for harmless ovarian cysts. Tumors shed cells and cell fragments into any fluid that surrounds them. Fluids from cysts in the pancreas, kidney, and thyroid are routinely examined to identify whether they contain cancerous cells. Now, Wang, Sundfeldt et al. show that ovarian cancers also shed DNA into the surrounding cyst fluid. Furthermore, mutations found in this DNA can provide valuable information about whether the cysts are cancerous. The study was performed by extracting DNA from the fluid in ovarian cysts that had been surgically removed from 77 women. Of these cysts, 10 were harmless cysts, 12 were benign tumors, 31 were invasive cancers, and 24 were so-called borderline tumors, which fall somewhere between the benign tumors and invasive cancers. Only cysts associated with the borderline tumors and invasive cancers need to be surgically removed. Here, Wang, Sundfeldt et al. report that DNA mutations that are characteristic of ovarian cancers were found in 87% of the cysts associated with borderline tumors and invasive cancers. In contrast, these mutations were not found in any of the cysts that do not require surgery. Fluid can be extracted from an ovarian cyst with a needle during an outpatient visit. Therefore, the results presented by Wang, Sundfeldt et al. suggest a relatively straightforward way of testing the DNA from ovarian cysts before deciding whether surgery is really necessary. First, however, larger studies that follow women with cysts over time will be necessary to confirm that this type of testing is effective and safe. DOI: http://dx.doi.org/10.7554/eLife.15175.002

Detection of circulating tumor DNA (ctDNA) after resection of stage II colon cancer may identify patients at the highest risk of recurrence and help inform adjuvant treatment decisions. We used massively parallel sequencing–based assays to evaluate the ability of ctDNA to detect minimal residual disease in 1046 plasma samples from a prospective cohort of 230 patients with resected stage II colon cancer. In patients not treated with adjuvant chemotherapy, ctDNA was detected postoperatively in 14 of 178 (7.9%) patients, 11 (79%) of whom had recurred at a median follow-up of 27 months; recurrence occurred in only 16 (9.8 %) of 164 patients with negative ctDNA [hazard ratio (HR), 18; 95% confidence interval (CI), 7.9 to 40; P < 0.001]. In patients treated with chemotherapy, the presence of ctDNA after completion of chemotherapy was also associated with an inferior recurrence-free survival (HR, 11; 95% CI, 1.8 to 68; P = 0.001). ctDNA detection after stage II colon cancer resection provides direct evidence of residual disease and identifies patients at very high risk of recurrence.

TERT promoter mutations (TERT-mut) are detectable in the majority of urothelial carcinomas. The detection of TERT-mut in urine is under investigation as a potential urine-based molecular-screening assay for bladder cancer. A small but significant number of bladder carcinomas are pure squamous cell carcinoma. We sought to assess the incidence of TERT-mut in squamous cell carcinoma of the urinary bladder. A retrospective search of the institutional pathology archives yielded 15 cystectomy specimens performed for squamous cell carcinoma (2000–2014). Histologic slides were reviewed by a senior urologic pathologist to confirm the diagnosis and select a representative formalin-fixed paraffin-embedded tissue block for mutational analysis. All cases yielded adequate material for DNA analysis. Sequencing for TERT-mut was performed using previously described SafeSeq technique. We detected TERT-mut in 12/15 (80%) of bladder squamous cell carcinomas. TERT promoter mutations, commonly found in conventional urothelial carcinoma, are also highly prevalent in urinary bladder squamous cell carcinoma suggesting a common tumorigenesis and potential utility as a molecular urine-based-screening assay.

Objective: Our objective was to develop an approach for selecting combinatorial markers of pathology from diverse clinical data types. We demonstrate this approach on the problem of pancreatic cyst classification. Materials and Methods: We analyzed 1026 patients with surgically resected pancreatic cysts, comprising 584 intraductal papillary mucinous neoplasms, 332 serous cystadenomas, 78 mucinous cystic neoplasms, and 42 solid-pseudopapillary neoplasms. To derive optimal markers for cyst classification from the preoperative clinical and radiological data, we developed a statistical approach for combining any number of categorical, dichotomous, or continuous-valued clinical parameters into individual predictors of pathology. The approach is unbiased and statistically rigorous. Millions of feature combinations were tested using 10-fold cross-validation, and the most informative features were validated in an independent cohort of 130 patients with surgically resected pancreatic cysts. Results: We identified combinatorial clinical markers that classified serous cystadenomas with 95% sensitivity and 83% specificity; solid-pseudopapillary neoplasms with 89% sensitivity and 86% specificity; mucinous cystic neoplasms with 91% sensitivity and 83% specificity; and intraductal papillary mucinous neoplasms with 94% sensitivity and 90% specificity. No individual features were as accurate as the combination markers. We further validated these combinatorial markers on an independent cohort of 130 pancreatic cysts, and achieved high and well-balanced accuracies. Overall sensitivity and specificity for identifying patients requiring surgical resection was 84% and 81%, respectively. Conclusions: Our approach identified combinatorial markers for pancreatic cyst classification that had improved performance relative to the individual features they comprise. In principle, this approach can be applied to any clinical dataset comprising dichotomous, categorical, and continuous-valued parameters.

Rare circulating tumor cells (CTCs) present in the bloodstream of patients with cancer provide a potentially accessible source for detection, characterization, and monitoring of nonhematological cancers. We previously demonstrated the effectiveness of a microfluidic device, the CTC-Chip, in capturing these epithelial cell adhesion molecule (EpCAM)-expressing cells using antibody-coated microposts. Here, we describe a high-throughput microfluidic mixing device, the herringbone-chip, or “HB-Chip,” which provides an enhanced platform for CTC isolation. The HB-Chip design applies passive mixing of blood cells through the generation of microvortices to significantly increase the number of interactions between target CTCs and the antibody-coated chip surface. Efficient cell capture was validated using defined numbers of cancer cells spiked into control blood, and clinical utility was demonstrated in specimens from patients with prostate cancer. CTCs were detected in 14 of 15 (93%) patients with metastatic disease (median = 63 CTCs/mL, mean = 386 ± 238 CTCs/mL), and the tumor-specific TMPRSS2-ERG translocation was readily identified following RNA isolation and RT-PCR analysis. The use of transparent materials allowed for imaging of the captured CTCs using standard clinical histopathological stains, in addition to immunofluorescence-conjugated antibodies. In a subset of patient samples, the low shear design of the HB-Chip revealed microclusters of CTCs, previously unappreciated tumor cell aggregates that may contribute to the hematogenous dissemination of cancer.

To explore the potential of tumor-specific DNA as a biomarker for head and neck squamous cell carcinomas (HNSCC), we queried DNA from saliva or plasma of 93 HNSCC patients. We searched for somatic mutations or human papillomavirus genes, collectively referred to as tumor DNA. When both plasma and saliva were tested, tumor DNA was detected in 96% of 47 patients. The fractions of patients with detectable tumor DNA in early- and late-stage disease were 100% (n = 10) and 95% (n = 37), respectively. When segregated by site, tumor DNA was detected in 100% (n = 15), 91% (n = 22), 100% (n = 7), and 100% (n = 3) of patients with tumors of the oral cavity, oropharynx, larynx, and hypopharynx, respectively. In saliva, tumor DNA was found in 100% of patients with oral cavity cancers and in 47 to 70% of patients with cancers of the other sites. In plasma, tumor DNA was found in 80% of patients with oral cavity cancers, and in 86 to 100% of patients with cancers of the other sites. Thus, saliva is preferentially enriched for tumor DNA from the oral cavity, whereas plasma is preferentially enriched for tumor DNA from the other sites. Tumor DNA in saliva was found postsurgically in three patients before clinical diagnosis of recurrence, but in none of the five patients without recurrence. Tumor DNA in the saliva and plasma appears to be a potentially valuable biomarker for detection of HNSCC.

Glioblastoma (GBM) is a highly aggressive brain cancer characterized by local invasion and angiogenic recruitment, yet metastatic dissemination is extremely rare. Here, we adapted a microfluidic device to deplete hematopoietic cells from blood specimens of patients with GBM, uncovering evidence of circulating brain tumor cells (CTC). Staining and scoring criteria for GBM CTCs were first established using orthotopic patient-derived xenografts (PDX), and then applied clinically: CTCs were identified in at least one blood specimen from 13 of 33 patients (39%; 26 of 87 samples). Single GBM CTCs isolated from both patients and mouse PDX models demonstrated enrichment for mesenchymal over neural differentiation markers compared with primary GBMs. Within primary GBMs, RNA in situ hybridization identified a subpopulation of highly migratory mesenchymal tumor cells, and in a rare patient with disseminated GBM, systemic lesions were exclusively mesenchymal. Thus, a mesenchymal subset of GBM cells invades the vasculature and may proliferate outside the brain. Significance: GBMs are locally invasive within the brain but rarely metastasize to distant organs, exemplifying the debate over “seed” versus “soil.” We demonstrate that GBMs shed CTCs with invasive mesenchymal characteristics into the circulation. Rare metastatic GBM lesions are primarily mesenchymal and show additional mutations absent in the primary tumor. Cancer Discov; 4(11); 1299–1309. ©2014 AACR. See related commentary by Seoane and De Mattos-Arruda, p. 1259 This article is highlighted in the In This Issue feature, p. 1243

3511Background: The conventional approach to testing the benefit of adjuvant therapies in patients (pts) with relatively favorable prognoses is to follow a large number of pts for long periods of t...

e15131Background: In pts with metastatic colorectal cancer (mCRC), the resection of isolated CLM is potentially curative. Previous studies have shown that ctDNA can be detected in a high proportion...

Rare circulating tumor cells (CTCs) are present in the blood of patients with metastatic epithelial cancers but have been difficult to measure routinely. We report a quantitative automated imaging system for analysis of prostate CTCs, taking advantage of prostate-specific antigen (PSA), a unique prostate tumor–associated marker. The specificity of PSA staining enabled optimization of criteria for baseline image intensity, morphometric measurements, and integration of multiple signals in a three-dimensional microfluidic device. In a pilot analysis, we detected CTCs in prostate cancer patients with localized disease, before surgical tumor removal in 8 of 19 (42%) patients (range, 38 to 222 CTCs per milliliter). For 6 of the 8 patients with preoperative CTCs, a precipitous postoperative decline (

Glioblastoma (GBM), the most common and aggressive form of glioma, is often heterogeneous, diffusely invasive and hypervascularized. Despite being aggressive, extracranial metastases are rare, suggesting constraints on hematologic dissemination or distant survival of primary GBM cells. We recently developed a novel microfluidic device, termed the CTC-iChip, for efficient, antigen agnostic capture of rare circulating tumor cells (CTCs). Using the CTC-iChip, we set out to determine whether GBM cells can be detected in the blood of mice using two orthotopic xenograft models representing diffuse (GBM8) and focal (GBM24) GBM. CTCs were identified in 5/11 and 2/5 mice bearing GBM8 and GBM24 xenografts, respectively. CTC numbers did not correlate with tumor size or latency. We then expanded our analysis to patients and identified CTCs in 12/38 GBM patients with a median 5.3 cells per ml (range: 0 to 48.2 cells per ml). To understand the molecular characteristics of GBM CTCs, we analyzed the expression of 49 GBM-specific and stem cell transcripts in single GBM CTCs from both mouse xenografts models as well as GBM patients. The expression of mesenchymal gene transcripts including VIM, TGFBR2, TGFB, and SERPINE1 was elevated in CTCs compared with cultured cells and matched primary tumor cells. Moreover, CTCs exhibited lower proliferative indices and decreased neural lineage transcripts. To determine the pathophysiologic significance of this expression profile and the prospective origin of GBM CTCs, RNA-ISH was performed on xenografts and patient tumor samples. In the highly migratory GBM8 xenograft model, broad tumor cell expression of CTC/mesenchymal transcripts was observed. However, in the GBM24 focal tumor growth model, CTC/mesenchymal gene transcripts were predominantly expressed in regions of tumor invasion, migration along fiber tracts, and around regions of necrosis. Similarly, RNA-ISH analysis of 6 GBM patient tumors revealed prominent expression of CTC/mesenchymal genes in peri-necrotic and migratory pseudopalisading cells. Finally, RNA-ISH analysis of a rare case of metastatic GBM revealed a significant enrichment of GBM/mesenchymal gene expressing tumor cells within lung and lymph node metastases. Taken together, these data provide the first evidence for the hematologic circulation of GBM cells and reveal the involvement of mesenchymal features in the pathophysiology of malignant brain tumors. Citation Format: James P. Sullivan, Brian V. Nahed, Andrew S. Chi, Marissa N. Madden, Samantha M. Oliveira, Simeon Springer, Hiroaki Wakimoto, Deepak Bhere, Khalid Shah, Phil Spuhler, Ajay M. Shah, David N. Louis, Mehmet Toner, Shyamala Maheswaran, Daniel A. Haber. Molecular characterization of circulating glioblastoma cells identifies a mesenchymal-like tumor cell subpopulation. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4004. doi:10.1158/1538-7445.AM2014-4004