Cumulative incidence of false-positive results in repeated, multimodal cancer screening

Biomarkers in Cancer Screening: Promises and Challenges in Cancer Early Detection

Cancer continues to be one the leading causes of death worldwide, primarily due to the late detection of the disease. Cancers detected at early stages may enable more effective intervention of the disease. However, most cancers lack well-established screening procedures except for cancers with an established early asymptomatic phase and clinically validated screening tests. There is a critical need to identify and develop assays/tools in conjunction with imaging approaches for precise screening and detection of the aggressive disease at an early stage. New developments in molecular cancer screening and early detection include germline testing, synthetic biomarkers, and liquid biopsy approaches.

Cancer screening with multicancer detection tests: A translational science review

Multicancer detection (MCD) tests use a single, easily obtainable biospecimen, such as blood, to screen for more than one cancer concurrently. MCD tests can potentially be used to improve early cancer detection, including cancers that currently lack effective screening methods. However, these tests have unknown and unquantified benefits and harms. MCD tests differ from conventional cancer screening tests in that the organ responsible for a positive test is unknown, and a broad diagnostic workup may be necessary to confirm the location and type of underlying cancer. Among two prospective studies involving greater than 16,000 individuals, MCD tests identified those who had some cancers without currently recommended screening tests, including pancreas, ovary, liver, uterus, small intestine, oropharyngeal, bone, thyroid, and hematologic malignancies, at early stages. Reported MCD test sensitivities range from 27% to 95% but differ by organ and are lower for early stage cancers, for which treatment toxicity would be lowest and the potential for cure might be highest. False reassurance from a negative MCD result may reduce screening adherence, risking a loss in proven public health benefits from standard-of-care screening. Prospective clinical trials are needed to address uncertainties about MCD accuracy to detect different cancers in asymptomatic individuals, whether these tests can detect cancer sufficiently early for effective treatment and mortality reduction, the degree to which these tests may contribute to cancer overdiagnosis and overtreatment, whether MCD tests work equally well across all populations, and the appropriate diagnostic evaluation and follow-up for patients with a positive test.

Revisiting the standard blueprint for biomarker development to address emerging cancer early detection technologies

Novel liquid biopsy technologies are creating a watershed moment in cancer early detection. Evidence supporting population screening is nascent, but a rush to market the new tests is prompting cancer early detection researchers to revisit the standard blueprint that the Early Detection Research Network established to evaluate novel screening biomarkers. In this commentary, we review the Early Detection Research Network's Phases of Biomarker Development (PBD) for rigorous evaluation of novel early detection biomarkers and discuss both hazards and opportunities involved in expedited evaluation. According to the PBD, for a biomarker-based test to be considered for population screening, 1) test sensitivity in a prospective screening setting must be adequate, 2) the shift to early curable stages must be meaningful, and 3) any stage shift must translate into clinically significant mortality benefit. In the past, determining mortality benefit has required lengthy randomized screening trials, but interest is growing in expedited trial designs with shorter-term endpoints. Whether and how best to use such endpoints in a manner that retains the rigor of the PBD remains to be determined. We discuss how computational disease modeling can be harnessed to learn about screening impact and meet the needs of the moment.

Multi-Cancer Early Detection: The New Frontier in Cancer Early Detection

The new generation of cancer early detection tests holds remarkable promise for revolutionizing and changing the paradigm of cancer early detection. Dozens of cancer early detection tests are being developed and evaluated. Some are already commercialized and available for use, most as a complement to and not in place of existing recommended cancer screening tests. This review evaluates existing single- and multi-cancer early detection tests (MCEDs), discussing their performance characteristics including sensitivity, specificity, positive and negative predictive values, and accuracy. It also critically looks at the potential harms that could result from these tests, including false positive and negative results, the risk of overdiagnosis and overtreatment, psychological and economic harms, and the risk of widening cancer inequities. We also review the large-scale, population-based studies that are being launched in the United States and United Kingdom to determine the impact of MCEDs on clinically relevant outcomes and implications for current practice.

Prostate cancer screening in African American men: a review of the evidence

BACKGROUND

Prostate cancer is the most diagnosed cancer in African American men, yet prostate cancer screening regimens in this group are poorly guided by existing evidence, given underrepresentation of African American men in prostate cancer screening trials. It is critical to optimize prostate cancer screening and early detection in this high-risk group because underdiagnosis may lead to later-stage cancers at diagnosis and higher mortality while overdiagnosis may lead to unnecessary treatment.

METHODS

We performed a review of the literature related to prostate cancer screening and early detection specific to African American men to summarize the existing evidence available to guide health-care practice.

RESULTS

Limited evidence from observational and modeling studies suggests that African American men should be screened for prostate cancer. Consideration should be given to initiating screening of African American men at younger ages (eg, 45-50 years) and at more frequent intervals relative to other racial groups in the United States. Screening intervals can be optimized by using a baseline prostate-specific antigen measurement in midlife. Finally, no evidence has indicated that African American men would benefit from screening beyond 75 years of age; in fact, this group may experience higher rates of overdiagnosis at older ages.

CONCLUSIONS

The evidence base for prostate cancer screening in African American men is limited by the lack of large, randomized studies. Our literature search supported the need for African American men to be screened for prostate cancer, for initiating screening at younger ages (45-50 years), and perhaps screening at more frequent intervals relative to men of other racial groups in the United States.

Dying To Find Out: The Cost of Time at the Dawn of the Multicancer Early Detection Era

Cancer is a significant burden worldwide that adversely impacts life expectancy, quality of life, health care costs, and workforce productivity. Although currently recommended screening tests for individual cancers reduce mortality, they detect only a minority of all cancers and sacrifice specificity for high sensitivity, resulting in a high cumulative rate of false positives. Blood-based multicancer early detection tests (MCED) based on next-generation sequencing (NGS) and other technologies hold promise for broadening the number of cancer types detected in screened populations and hope for reducing cancer mortality. The promise of this new technology to improve cancer detection rates and make screening more efficient at the population level demands the development of novel trial designs that accelerate clinical adoption. Carefully designed clinical trials are needed to address these issues.

Modelled mortality benefits of multi-cancer early detection screening in England

BACKGROUND

Screening programmes utilising blood-based multi-cancer early detection (MCED) tests, which can detect a shared cancer signal from any site in the body with a single, low false-positive rate, could reduce cancer burden through early diagnosis.

METHODS

A natural history ('interception') model of cancer was previously used to characterise potential benefits of MCED screening (based on published performance of an MCED test). We built upon this using a two-population survival model to account for an increased risk of death from cfDNA-detectable cancers relative to cfDNA-non-detectable cancers. We developed another model allowing some cancers to metastasise directly from stage I, bypassing intermediate tumour stages. We used incidence and survival-by-stage data from the National Cancer Registration and Analysis Service in England to estimate longer-term benefits to a cohort screened between ages 50-79 years.

RESULTS

Estimated late-stage and mortality reductions were robust to a range of assumptions. With the least favourable dwell (sojourn) time and cfDNA status hazard ratio assumptions, we estimated, among 100,000 screened individuals, 67 (17%) fewer cancer deaths per year corresponding to 2029 fewer deaths in those screened between ages 50-79 years.

CONCLUSION

Realising the potential benefits of MCED tests could substantially reduce late-stage cancer diagnoses and mortality.

Modeled residual current cancer risk after clinical investigation of a positive multicancer early detection test result

BACKGROUND

Positive results of a multi-cancer early detection (MCED) test require confirmatory diagnostic workup. Here, residual current cancer risk (RR) during the process of diagnostic resolution, including situations where the initial confirmatory test does not provide resolution, was modeled.

METHODS

A decision-tree framework was used to model conditional risk in a patient's journey through confirmatory diagnostic options and outcomes. The diagnostic journey assumed that cancer signal detection (a positive MCED test result) had already led to a transition from screening to diagnosis and began with an initial positive predictive value (PPV) from the positive result. Evaluation of a most probable (top) predicted cancer signal origin (CSO) and then a second-most probable predicted CSO followed. Under the assumption that the top- and second-predicted CSOs were each followed by a targeted confirmatory test, the RR was estimated for each subsequent scenario.

RESULTS

For an initial MCED test result with typical performance characteristics modeled (PPV, 40%; top-predicted CSO accuracy, 90%), after a negative initial confirmatory test (sensitivity, 70%, 90%, or 100%) the RR ranged from 6% to 20%. A second-predicted CSO (accuracy, 50%), after a negative second confirmatory test, still provided a significant RR (3%-18%) in comparison with the National Institute for Health and Care Excellence-recommended cancer risk threshold warranting investigation in symptomatic individuals (3%). With a 40% PPV for an MCED test and 90% specificity for a confirmatory test, the risk of incidental findings after one or two confirmatory tests was 6% and 12%, respectively.

CONCLUSIONS

These results may illustrate the impact of a positive MCED test on follow-up decision-making.

Analytical validation of a multi-cancer early detection test with cancer signal origin using a cell-free DNA-based targeted methylation assay

The analytical validation is reported for a targeted methylation-based cell-free DNA multi-cancer early detection test designed to detect cancer and predict the cancer signal origin (tissue of origin). A machine-learning classifier was used to analyze the methylation patterns of >105 genomic targets covering >1 million methylation sites. Analytical sensitivity (limit of detection [95% probability]) was characterized with respect to tumor content by expected variant allele frequency and was determined to be 0.07%-0.17% across five tumor cases and 0.51% for the lymphoid neoplasm case. Test specificity was 99.3% (95% confidence interval, 98.6-99.7%). In the reproducibility and repeatability study, results were consistent in 31/34 (91.2%) pairs with cancer and 17/17 (100%) pairs without cancer; between runs, results were concordant for 129/133 (97.0%) cancer and 37/37 (100%) non-cancer sample pairs. Across 3- to 100-ng input levels of cell-free DNA, cancer was detected in 157/182 (86.3%) cancer samples but not in any of the 62 non-cancer samples. In input titration tests, cancer signal origin was correctly predicted in all tumor samples detected as cancer. No cross-contamination events were observed. No potential interferent (hemoglobin, bilirubin, triglycerides, genomic DNA) affected performance. The results of this analytical validation study support continued clinical development of a targeted methylation cell-free DNA multi-cancer early detection test.

A review of sensors for classification and subtype discrimination of cancer: Insights into circulating tumor cells and tumor-derived extracellular vesicles

Liquid biopsy can reflect the state of tumors in vivo non-invasively, thus providing a strong basis for the early diagnosis, individualized treatment monitoring and prognosis of tumors. Circulating tumor cells (CTCs) and tumor-derived extracellular vesicles (tdEVs) contain information-rich components, such as nucleic acids and proteins, and they are essential markers for liquid biopsies. Their capture and analysis are of great importance for the study of disease occurrence and development and, consequently, have been the subject of many reviews. However, both CTCs and tdEVs carry the biological characteristics of their original tissue, and few reviews have focused on their function in the staging and classification of cancer. In this review, we focus on state-of-the-art sensors based on the simultaneous detection of multiple biomarkers within CTCs and tdEVs, with clinical applications centered on cancer classification and subtyping. We also provide a thorough discussion of the current challenges and prospects for novel sensors with the ultimate goal of cancer classification and staging. It is hoped that these most advanced technologies will bring new insights into the clinical practice of cancer screening and diagnosis.

Estimating the lifetime risk of a false positive screening test result

False positive results in screening tests have potentially severe psychological, medical, and financial consequences for the recipient. However, there have been few efforts to quantify how the risk of a false positive accumulates over time. We seek to fill this gap by estimating the probability that an individual who adheres to the U.S. Preventive Services Task Force (USPSTF) screening guidelines will receive at least one false positive in a lifetime. To do so, we assembled a data set of 116 studies cited by the USPSTF that report the number of true positives, false negatives, true negatives, and false positives for the primary screening procedure for one of five cancers or six sexually transmitted diseases. We use these data to estimate the probability that an individual in one of 14 demographic subpopulations will receive at least one false positive for one of these eleven diseases in a lifetime. We specify a suitable statistical model to account for the hierarchical structure of the data, and we use the parametric bootstrap to quantify the uncertainty surrounding our estimates. The estimated probability of receiving at least one false positive in a lifetime is 85.5% (±0.9%) and 38.9% (±3.6%) for baseline groups of women and men, respectively. It is higher for subpopulations recommended to screen more frequently than the baseline, including more vulnerable groups such as pregnant women and men who have sex with men. Since screening technology is imperfect, false positives remain inevitable. The high lifetime risk of a false positive reveals the importance of educating patients about this phenomenon.

Kan Plazmasında Satellit-2 Tekrar Elementi DNA Dizilerinin Karakterizasyonu

Amaç: Son yıllarda tıp biliminin farklı disiplinlerinde sıkça karşılaşılan kavramlardan biri olan “sıvı biyopsi”, hastaların tanı, prognoz analizi ve tedaviye cevabını değerlendirme gibi konularda girişimsel doku biyopsisi yerine, kan ve çeşitli vücut sıvılarındaki moleküler ve epigenetik biyobelirteçlerin kullanılmasını içerir. Dolaşımda serbest halde dolaşan DNA’da (‘cell-free DNA’, cfDNA) kanser hücrelerine özgü gen mutasyonlarının saptanması, kanser hücrelerinin içeriğinin vücut sıvılarına geçtiğinin kesin kanıtı olarak kabul edilmektedir. cfDNA’nın bileşiminin belirlenmesine yönelik dizileme çalışmaları, perisentrik satellit DNA dizilerinin, cfDNA’da genom oranlarına kıyasla daha fazla oranda temsil edildiğini bildirmiştir. Bu çalışmada, kanser açısından spesifik dizilerin saptanması amacıyla, Sat-2 dizilerinin polimeraz zincir reaksiyonunda (PCR) çoğaltılmaları sonrasında daha detaylı karakterizasyonu amaçlanmıştır.Yöntem: Çalışmada, sağlıklı ve metastatik meme kanserli hastaların plazmalarından 1. ve 10. kromozoma spesifik Sat-2 dizileri PCR ile çoğaltıldıktan sonra, otomatik elektroforez sisteminde ayrıştırıldılar.Bulgular: Yapılan büyüklük analizinde, iki bölgeden çok sayıda amplikon oluştuğu, bunların yaklaşık %50’ni sırasıyla 143 ve 115 bç uzunluğunda ürünlerin oluşturduğu belirlenmiştir. Bu iki PCR amplikonunun miktarı meme kanserli hastalarda daha yüksek olarak hesaplandı. Onuncu kromozoma özgü 115 bç’lik fargman dışındaki Sat-2 dizileri açısından kontroller ile hastalar arasında önemli farklar olduğu belirlenmiştir.Sonuç: Çalışma kapsamında elde edilen bulgular, Sat-2 tekrar elementine ait DNA dizilerinin sekanslanması sonrası kansere spesifik hedef bölgelerin saptanabileceğini ortaya koymaktadır. 

Evaluation of cell-free DNA approaches for multi-cancer early detection

In the Circulating Cell-free Genome Atlas (NCT02889978) substudy 1, we evaluate several approaches for a circulating cell-free DNA (cfDNA)-based multi-cancer early detection (MCED) test by defining clinical limit of detection (LOD) based on circulating tumor allele fraction (cTAF), enabling performance comparisons. Among 10 machine-learning classifiers trained on the same samples and independently validated, when evaluated at 98% specificity, those using whole-genome (WG) methylation, single nucleotide variants with paired white blood cell background removal, and combined scores from classifiers evaluated in this study show the highest cancer signal detection sensitivities. Compared with clinical stage and tumor type, cTAF is a more significant predictor of classifier performance and may more closely reflect tumor biology. Clinical LODs mirror relative sensitivities for all approaches. The WG methylation feature best predicts cancer signal origin. WG methylation is the most promising technology for MCED and informs development of a targeted methylation MCED test.

Cell-Free DNA-Based Multi-Cancer Early Detection Test in an Asymptomatic Screening Population (NHS-Galleri): Design of a Pragmatic, Prospective Randomised Controlled Trial

We report the design of the NHS-Galleri trial (ISRCTN91431511), aiming to establish whether a multi-cancer early detection (MCED) test that screens asymptomatic individuals for cancer can reduce late-stage cancer incidence. This randomised controlled trial has invited approximately 1.5 million persons and enrolled over 140,000 from the general population of England (50-77 years; ≥3 years without cancer diagnosis or treatment; not undergoing investigation for suspected cancer). Blood is being collected at up to three annual visits. Following baseline blood collection, participants are randomised 1:1 to the intervention (blood tested by MCED test) or control (blood stored) arm. Only participants in the intervention arm with a cancer signal detected have results returned and are referred for urgent investigations and potential treatment. Remaining participants in both arms stay blinded and return for their next visit. Participants are encouraged to continue other NHS cancer screening programmes and seek help for new or unusual symptoms. The primary objective is to demonstrate a statistically significant reduction in the incidence rate of stage III and IV cancers diagnosed in the intervention versus control arm 3-4 years after randomisation. NHS-Galleri will help determine the clinical utility of population screening with an MCED test.

A Novel Blood-Based microRNA Diagnostic Model with High Accuracy for Multi-Cancer Early Detection

Early detection is critical to reduce cancer deaths as treating early stage cancers is more likely to be successful. However, patients with early stage diseases are often asymptomatic and thus less likely to be diagnosed. Here, we utilized four microarray datasets with a standardized platform to investigate comprehensive microRNA expression profiles from 7536 serum samples. A 4-miRNA diagnostic model was developed from the lung cancer training set (n = 416, 208 lung cancer patients and 208 non-cancer participants). The model showed 99% sensitivity and specificity in the lung cancer validation set (n = 3328, 1358 cancer patients and 1970 non-cancer participants); and the sensitivity remained to be >99% for patients with stage 1 disease. When applied to the additional combined dataset of 3792 participants including 2038 cancer patients across 12 different cancer types and 1754 independent non-cancer controls, the model demonstrated high sensitivities ranging from 83.2 to 100% for biliary tract, bladder, colorectal, esophageal, gastric, glioma, liver, pancreatic, and prostate cancers, and showed reasonable sensitivities of 68.2 and 72.0% for ovarian cancer and sarcoma, respectively, while maintaining 99.3% specificity. Our study provided a proof-of-concept data in demonstrating that the 4-miRNA model has the potential to be developed into a simple, inexpensive and noninvasive blood test for early detection of multiple cancers with high accuracy.

Opportunities for Early Cancer Detection: The Rise of ctDNA Methylation-Based Pan-Cancer Screening Technologies

The efficiency of conventional screening programs to identify early-stage malignancies can be limited by the low number of cancers recommended for screening as well as the high cumulative false-positive rate, and associated iatrogenic burden, resulting from repeated multimodal testing. The opportunity to use minimally invasive liquid biopsy testing to screen asymptomatic individuals at-risk for multiple cancers simultaneously could benefit from the aggregated diseases prevalence and a fixed specificity. Increasing both latter parameters is paramount to mediate high positive predictive value—a useful metric to evaluate a screening test accuracy and its potential harm-benefit. Thus, the use of a single test for multi-cancer early detection (stMCED) has emerged as an appealing strategy for increasing early cancer detection rate efficiency and benefit population health. A recent flurry of these stMCED technologies have been reported for clinical potential; however, their development is facing unique challenges to effectively improve clinical cost–benefit. One promising avenue is the analysis of circulating tumour DNA (ctDNA) for detecting DNA methylation biomarker fingerprints of malignancies—a hallmark of disease aetiology and progression holding the potential to be tissue- and cancer-type specific. Utilizing panels of epigenetic biomarkers could potentially help to detect earlier stages of malignancies as well as identify a tumour of origin from blood testing, useful information for follow-up clinical decision making and subsequent patient care improvement. Overall, this review collates the latest and most promising stMCED methodologies, summarizes their clinical performances, and discusses the specific requirements multi-cancer tests should meet to be successfully implemented into screening guidelines.

The PATHFINDER Study: Assessment of the Implementation of an Investigational Multi-Cancer Early Detection Test into Clinical Practice

To examine the extent of the evaluation required to achieve diagnostic resolution and the test performance characteristics of a targeted methylation cell-free DNA (cfDNA)-based multi-cancer early detection (MCED) test, ~6200 participants ≥50 years with (cohort A) or without (cohort B) ≥1 of 3 additional specific cancer risk factors will be enrolled in PATHFINDER (NCT04241796), a prospective, longitudinal, interventional, multi-center study. Plasma cfDNA from blood samples will be analyzed to detect abnormally methylated DNA associated with cancer (i.e., cancer "signal") and a cancer signal origin (i.e., tissue of origin). Participants with a "signal detected" will undergo further diagnostic evaluation per guiding physician discretion; those with a "signal not detected" will be advised to continue guideline-recommended screening. The primary objective will be to assess the number and types of subsequent diagnostic tests needed for diagnostic resolution. Based on microsimulations (using estimates of cancer incidence and dwell times) of the typical risk profiles of anticipated participants, the median (95% CI) number of participants with a "signal detected" result is expected to be 106 (87-128). Subsequent diagnostic evaluation is expected to detect 52 (39-67) cancers. The positive predictive value of the MCED test is expected to be 49% (39-58%). PATHFINDER will evaluate the integration of a cfDNA-based MCED test into existing clinical cancer diagnostic pathways. The study design of PATHFINDER is described here.

Clinical validation of a targeted methylation-based multi-cancer early detection test using an independent validation set

BACKGROUND

A multi-cancer early detection (MCED) test used to complement existing screening could increase the number of cancers detected through population screening, potentially improving clinical outcomes. The Circulating Cell-free Genome Atlas study (CCGA; NCT02889978) was a prospective, case-controlled, observational study and demonstrated that a blood-based MCED test utilizing cell-free DNA (cfDNA) sequencing in combination with machine learning could detect cancer signals across multiple cancer types and predict cancer signal origin (CSO) with high accuracy. The objective of this third and final CCGA substudy was to validate an MCED test version further refined for use as a screening tool.

PATIENTS AND METHODS

This pre-specified substudy included 4077 participants in an independent validation set (cancer: n = 2823; non-cancer: n = 1254, non-cancer status confirmed at year-one follow-up). Specificity, sensitivity, and CSO prediction accuracy were measured.

RESULTS

Specificity for cancer signal detection was 99.5% [95% confidence interval (CI): 99.0% to 99.8%]. Overall sensitivity for cancer signal detection was 51.5% (49.6% to 53.3%); sensitivity increased with stage [stage I: 16.8% (14.5% to 19.5%), stage II: 40.4% (36.8% to 44.1%), stage III: 77.0% (73.4% to 80.3%), stage IV: 90.1% (87.5% to 92.2%)]. Stage I-III sensitivity was 67.6% (64.4% to 70.6%) in 12 pre-specified cancers that account for approximately two-thirds of annual USA cancer deaths and was 40.7% (38.7% to 42.9%) in all cancers. Cancer signals were detected across >50 cancer types. Overall accuracy of CSO prediction in true positives was 88.7% (87.0% to 90.2%).

CONCLUSION

In this pre-specified, large-scale, clinical validation substudy, the MCED test demonstrated high specificity and accuracy of CSO prediction and detected cancer signals across a wide diversity of cancers. These results support the feasibility of this blood-based MCED test as a complement to existing single-cancer screening tests.

CLINICAL TRIAL NUMBER

NCT02889978.

Is pre-biopsy serum prostate specific antigen retesting always justified? A study of the influence of individual and analytical factors on decision making for biopsy referral

BACKGROUND AND AIMS

We investigated factors influencing pre-biopsy prostate-specific antigen (PSA) retesting as recommended by clinical guidelines.

MATERIALS AND METHODS

333 patients screened for prostate cancer (PCa) repeated PSA (Roche Cobas systems) after a median of 3.9 months, before performing biopsy. Multiple regression models were used to assess effects of patients' characteristics on PSA results and changes over time.

RESULTS

PCa [n = 132 (40.7%)] and cancer-free [n = 192 (59.3%)] patients had similar rate of PSA positive results at baseline (84.8% vs. 83.9%, P = 0.931). Their rate of reversion to normal PSA after retesting was negligible (0.9% in PCa and 3.7% in PCa-free patients, P = 0.286). 31.1% of PCa and 31.3% of cancer-free patients (P = 0.426) showed a significant PSA increase after retesting. Age was a confounder since not only PSA increased in older PCa patients, but it was also related to PCa histological grade, in turn associated to PSA increase. In PCa-free patients, glandular inflammation, present in 1/3 of subjects, was also associated to higher PSA concentrations.

CONCLUSION

When obtained with the same immunoassay under controlled analytical conditions, a PSA positive result is confirmed after retesting in the great majority of screened patients. Neither analytical factors nor intraindividual variability appeared to justify PSA retesting before biopsy referral.

Modeled Reductions in Late-stage Cancer with a Multi-Cancer Early Detection Test

BACKGROUND

Cancer is the second leading cause of death globally, with many cases detected at a late stage when prognosis is poor. New technologies enabling multi-cancer early detection (MCED) may make "universal cancer screening" possible. We extend single-cancer models to understand the potential public health effects of adding a MCED test to usual care.

METHODS

We obtained data on stage-specific incidence and survival of all invasive cancers diagnosed in persons aged 50-79 between 2006 and 2015 from the US Surveillance, Epidemiology, and End Results (SEER) program, and combined this with published performance of a MCED test in a state transition model (interception model) to predict diagnostic yield, stage shift, and potential mortality reductions. We model long-term (incident) performance, accou.

Sensitive and specific multi-cancer detection and localization using methylation signatures in cell-free DNA

BACKGROUND

Early cancer detection could identify tumors at a time when outcomes are superior and treatment is less morbid. This prospective case-control sub-study (from NCT02889978 and NCT03085888) assessed the performance of targeted methylation analysis of circulating cell-free DNA (cfDNA) to detect and localize multiple cancer types across all stages at high specificity.

PARTICIPANTS AND METHODS

The 6689 participants [2482 cancer (>50 cancer types), 4207 non-cancer] were divided into training and validation sets. Plasma cfDNA underwent bisulfite sequencing targeting a panel of >100 000 informative methylation regions. A classifier was developed and validated for cancer detection and tissue of origin (TOO) localization.

RESULTS

Performance was consistent in training and validation sets. In validation, specificity was 99.3% [95% confidence interval (CI): 98.3% to 99.8%; 0.7% false-positive rate (FPR)]. Stage I-III sensitivity was 67.3% (CI: 60.7% to 73.3%) in a pre-specified set of 12 cancer types (anus, bladder, colon/rectum, esophagus, head and neck, liver/bile-duct, lung, lymphoma, ovary, pancreas, plasma cell neoplasm, stomach), which account for ∼63% of US cancer deaths annually, and was 43.9% (CI: 39.4% to 48.5%) in all cancer types. Detection increased with increasing stage: in the pre-specified cancer types sensitivity was 39% (CI: 27% to 52%) in stage I, 69% (CI: 56% to 80%) in stage II, 83% (CI: 75% to 90%) in stage III, and 92% (CI: 86% to 96%) in stage IV. In all cancer types sensitivity was 18% (CI: 13% to 25%) in stage I, 43% (CI: 35% to 51%) in stage II, 81% (CI: 73% to 87%) in stage III, and 93% (CI: 87% to 96%) in stage IV. TOO was predicted in 96% of samples with cancer-like signal; of those, the TOO localization was accurate in 93%.

CONCLUSIONS

cfDNA sequencing leveraging informative methylation patterns detected more than 50 cancer types across stages. Considering the potential value of early detection in deadly malignancies, further evaluation of this test is justified in prospective population-level studies.

The Dichotomous Nature of AZ5104 (an EGFR Inhibitor) Towards RORγ and RORγT

The RORC (RAR related orphan receptor C) gene produces two isoforms by alternative promoter usage: RORγ (nuclear receptor ROR-gamma isoform 1) and RORγT (nuclear receptor ROR-gamma isoform 1). Both proteins have distinct tissue distributions and are involved in several physiological processes, including glucose/lipid metabolism and the development of Th17 lymphocytes. Previously, we developed a stably transfected reporter cell line and used it to screen a library of kinase inhibitors. We found that AZ5104 acts as an RORγ agonist at low micromolar concentrations. Molecular docking analysis showed that this compound occupies the ligand binding domain of the receptor with a significant docking score. However, analysis of the biological activity of this compound in Th17 cells revealed that it downregulates RORγT expression and Th17-related cytokine production via inhibition of SRC-ERK-STAT3 (SRC proto-oncogene - extracellular regulated MAP kinase - signal transducer and activator of transcription 3). We thus identified a compound acting as an agonist of RORγ that, due to the inhibition of downstream elements of EGFR (epidermal growth factor receptor) signaling, exerts different biological activity towards a Th17-specific isoform. Additionally, our results may be relevant in the future for the design of treatments targeting signaling pathways that inhibit Th17-related inflammation in certain autoimmune disorders.

False-Positive Results in a Population-Based Colorectal Screening Program: Cumulative Risk from 2000 to 2017 with Biennial Screening

BACKGROUND

The aim of this study was to estimate the cumulative risk of a false-positive (FP) result in a fecal occult blood test (FOBT) through 7 screening rounds and to identify its associated factors in a population-based colorectal cancer screening program.

METHODS

Retrospective cohort study, which included participants ages 50 to 69 years of a colorectal cancer screening program in Catalonia, Spain. During this period, 2 FOBTs were used (guaiac and immunochemical). A discrete-time survival model was performed to identify risk factors of receiving a positive FOBT with no high-risk adenoma or colorectal cancer in the follow-up colonoscopy. We estimated the probability of having at least 1 FP over 7 screening rounds.

RESULTS

During the period of 2000 to 2017, the cumulative FP risk was 16.3% (IC_95%: 14.6%-18.3%), adjusted by age, sex, and type of test. The median number of screens was 2. Participants who began screening at age 50 years had a 7.3% [95% confidence interval (CI), 6.35-8.51] and a 12.4% (95% CI, 11.00-13.94) probability of an FP with 4 screening rounds of guaiac-based test and immunochemical test, respectively. Age, the fecal immunochemical test, first screening, and number of personal screens were factors associated with an FP result among screenees.

CONCLUSIONS

The cumulative risk of an FP in colorectal screening using FOBT seems acceptable as the colonoscopy, with its high accuracy, lengthens the time until additional colorectal screening is required, while complication rates remain low.

IMPACT

It is useful to determine the cumulative FP risk in cancer screening for both advising individuals and for health resources planning.

Can expressed prostatic secretions effect prostate biopsy decision of urologist?

Objectives:

To evaluate the frequency of NIH category IV prostatitis, and the use of expressed prostatic secretions tests in an effort to improve the reliability of prostate specific antigen as an indicator, to avoid unnecessary prostate biopsy.

Materials and Methods:

178 expressed prostatic secretion positive patients with serum prostate specific antigen levels of ≥ 2.5 ng / mL were included in present prospective study. The diagnostic evaluation included detailed history and physical examination, digital rectal examination, urine analysis, urine culture, and expressed prostatic secretions tests. Transrectal ultrasonography was used both to measure prostate volume and conduct 12 core prostate biopsy.

Results:

The prevalence of NIH category IV prostatitis was 36.9% (178 / 482) in our population of men. In our study patients (n: 178) prostate biopsy results were classified as; 66 prostatitis, 81 BPH, and 31 Pca. In asymptomatic prostatitis group, expressed prostatic secretion mean leucocyte ratio was higher compared to other two groups (p < 0.0001). The relation between number of expressed prostatic secretion leucocytes and prostatitis, benign prostate hyperplasia, and prostate cancer is analyzed. If 16 is taken as the cut of number for leucocyte presence, its sensitivity is 0.92 (AUC = 0.78 p = 0.01).

Conclusions:

The number of leucocytes in expressed prostatic secretion is higher in the chronic prostatitis group. If the leukocyte presence of 16 and above is taken as the cut off point, the sensitivity becomes 0.92 (AUC = 0.78). We firmly believe that our new cut off value may be used as to aid prostate specific antigen and derivates while giving biopsy decision.

A blueprint for cancer screening and early detection: Advancing screening's contribution to cancer control

From the mid-20th century, accumulating evidence has supported the introduction of screening for cancers of the cervix, breast, colon and rectum, prostate (via shared decisions), and lung. The opportunity to detect and treat precursor lesions and invasive disease at a more favorable stage has contributed substantially to reduced incidence, morbidity, and mortality. However, as new discoveries portend advancements in technology and risk-based screening, we fail to fulfill the greatest potential of the existing technology, in terms of both full access among the target population and the delivery of state-of-the art care at each crucial step in the cascade of events that characterize successful cancer screening. There also is insufficient commitment to invest in the development of new technologies, incentivize the development of new ideas, and rapidly evaluate promising new technology. In this report, the authors summarize the status of cancer screening and propose a blueprint for the nation to further advance the contribution of screening to cancer control.

Oferta e utilização de teleconsultorias para Atenção Primária à Saúde no Programa Telessaúde Brasil Redes

Objetivo: Avaliar a adequação do Programa Telessaúde Brasil Redes, no âmbito das teleconsultorias, a partir da análise de dados de estrutura e processo da Plataforma Nacional de Telessaúde. Método: Estudo descritivo, com análise estatística de série histórica (24 meses) da produção de teleconsultoria pelos núcleos de telessaúde que utilizaram a ferramenta de outubro de 2013 a setembro de 2015. Resultados: Foram respondidas 29.575 teleconsultorias por 18 núcleos de telessaúde em todo o país, para 43.421 usuários em 9.801 unidades de saúde. Oferta e demanda mensal variaram entre 0,92 a 2,06 e 0,22 a 1,00 teleconsultorias, respectivamente. O percentual de unidades de saúde com ao menos uma solicitação/mês manteve-se próximo a 0,1%, sendo que 87,3% dos usuários cadastrados não realizou nenhuma solicitação no período. Os temas solicitados cobriram todos os capítulos da Classificação Internacional da Atenção Primária e da Classificação Internacional de Doenças. A satisfação dos usuários foi de 95,6% e o percentual de dúvidas totalmente respondidas foi 88,4%. Conclusões: Apesar da oferta adequada em relação às metas do programa, a demanda é muito baixa, gerando capacidade instalada ociosa de um grupo de teleconsultores com capacidade de resposta para um amplo leque de temas. Levanta-se a necessidade de ganho de escala, integração horizontal e fortalecimento da telerregulação e da auditoria das ações de telessaúde, com centralização de recursos e redução do número de núcleos de telessaúde. Além disso, é necessário investir em novas tipologias sinérgicas e sistêmicas de oferta de ações de telessaúde, como o apoio ao complexo regulador ambulatorial e à orientação da população.

Diagnostic PET Imaging of Mammary Microcalcifications Using 64Cu-DOTA-Alendronate in a Rat Model of Breast Cancer

The development of improved breast cancer screening methods is hindered by a lack of cancer-specific imaging agents and effective small-animal models to test them. The purpose of this study was to evaluate ⁶⁴Cu-DOTA-alendronate as a mammary microcalcification-targeting PET imaging agent, using an ideal rat model. Our long-term goal is to develop ⁶⁴Cu-DOTA-alendronate for the detection and noninvasive differentiation of malignant versus benign breast tumors with PET. Methods: DOTA-alendronate was synthesized, radiolabeled with ⁶⁴Cu, and administered to normal or tumor-bearing aged, female, retired breeder Sprague-Dawley rats for PET imaging. Mammary tissues were subsequently labeled and imaged with light, confocal, and electron microscopy to verify microcalcification targeting specificity of DOTA-alendronate and elucidate the histologic and ultrastructural characteristics of the microcalcifications in different mammary tumor types. Tumor uptake, biodistribution, and dosimetry studies were performed to evaluate the efficacy and safety of ⁶⁴Cu-DOTA-alendronate. Results:⁶⁴Cu-DOTA-alendronate was radiolabeled with a 98% yield. PET imaging using aged, female, retired breeder rats showed specific binding of ⁶⁴Cu-DOTA-alendronate in mammary glands and mammary tumors. The highest uptake of ⁶⁴Cu-DOTA-alendronate was in malignant tumors and the lowest uptake in benign tumors and normal mammary tissue. Confocal analysis with carboxyfluorescein-alendronate confirmed the microcalcification binding specificity of alendronate derivatives. Biodistribution studies revealed tissue alendronate concentrations peaking within the first hour, then decreasing over the next 48 h. Our dosimetric analysis demonstrated a ⁶⁴Cu effective dose within the acceptable range for clinical PET imaging agents and the potential for translation into human patients. Conclusion:⁶⁴Cu-DOTA-alendronate is a promising PET imaging agent for the sensitive and specific detection of mammary tumors as well as the differentiation of malignant versus benign tumors based on absolute labeling uptake.

Analysis of binary responses with outcome-specific misclassification probability in genome-wide association studies

Errors in the binary status of some response traits are frequent in human, animal, and plant applications. These error rates tend to differ between cases and controls because diagnostic and screening tests have different sensitivity and specificity. This increases the inaccuracies of classifying individuals into correct groups, giving rise to both false-positive and false-negative cases. The analysis of these noisy binary responses due to misclassification will undoubtedly reduce the statistical power of genome-wide association studies (GWAS). A threshold model that accommodates varying diagnostic errors between cases and controls was investigated. A simulation study was carried out where several binary data sets (case-control) were generated with varying effects for the most influential single nucleotide polymorphisms (SNPs) and different diagnostic error rate for cases and controls. Each simulated data set consisted of 2000 individuals. Ignoring misclassification resulted in biased estimates of true influential SNP effects and inflated estimates for true noninfluential markers. A substantial reduction in bias and increase in accuracy ranging from 12% to 32% was observed when the misclassification procedure was invoked. In fact, the majority of influential SNPs that were not identified using the noisy data were captured using the proposed method. Additionally, truly misclassified binary records were identified with high probability using the proposed method. The superiority of the proposed method was maintained across different simulation parameters (misclassification rates and odds ratios) attesting to its robustness.

Do no harm: Balancing the costs and benefits of patient outcomes in health psychology research and practice

This article analyses research exploring medication adherence, help-seeking behaviour, screening and behaviour change to argue that all interventions have the potential for both benefit and harm. Accordingly, health psychology may have inadvertently contributed to psychological harms (e.g. lead times, anxiety, risk compensation and rebound effects); medical harms (e.g. medication side effects, unnecessary procedures) and social harms (e.g. financial costs, increased consultations rates). Such harms may result from medicalisation or pharmaceuticalisation. Or, they may reflect the ways in which we manage probabilities and an optimistic bias that emphasises benefit over cost.

Short-term Follow-up US Leads to Higher False-positive Results Without Detection of Structural Recurrences in PTMC

To investigate the value of the annual follow-up neck ultrasonography (US) for postoperative surveillance in patients with papillary thyroid microcarcinoma (PTMC). This retrospective study has been approved by our institutional review board (IRB) with waiver for informed consent. A total of 375 patients diagnosed as PTMCs, who underwent total thyroidectomy with radioiodine remnant ablation were included, to identify the recurrence rate and the false-positive rate of annual ultrasound. The number, interval, and the results of follow-up US or fine needle aspiration were obtained from electronic medical records. Four (1.1%, 4/375) recurrences were found 3 years after the initial treatment, and only 1 patient (0.3%, 1/375) had a metastatic lymph node larger than 8 mm in the shortest diameter on US found 7.6 years after initial treatment with biochemical abnormalities. Cumulative risk of having at least 1 false-positive exam was 8.3% by the 8th US, and 8.1% by the 8-9 year follow-up. Cox multivariate regression showed shorter interval of follow-up US and presence of lymph node metastasis at initial surgery are independent predictors affecting the cumulative false-positive results (hazard ratio [HR], 0.60; 95% confidence interval [CI]: 0.49-0.73; P < 0.001 and HR, 2.19; 95% CI: 1.01-4.75; P = 0.048, respectively). Short-term follow-up US can result in higher cumulative false-positive results without detection of meaningful recurrences in patients with PTMCs who do not have biochemical abnormalities.

Risk perception and psychological morbidity in men at elevated risk for prostate cancer

OBJECTIVE

As prostate-specific antigen (psa) makes prostate cancer (pca) screening more accessible, more men are being identified with conditions that indicate high risk for developing pca, such as elevated psa and high-grade intraepithelial neoplasia (hgpin). In the present study, we assessed psychological well-being and risk perception in individuals with those high-risk conditions.

METHODS

A questionnaire consisting of a psychological symptom survey, a trait risk-aversion survey, and a cancer-specific risk perception survey was administered to 168 patients with early-stage localized pca and 69 patients at high risk for pca (n = 16 hgpin, n = 53 psa > 4 ng/mL). Analysis of variance was used to examine differences in psychological well-being and appraisal of risk between the groups.

RESULTS

Compared with the pca group, the high-risk group perceived their risk of dying from something other than pca to be significantly lower (p = 0.007). However, pca patients reported significantly more clinically important psychological symptoms.

CONCLUSIONS

The identification of prostate conditions that predict progression to cancer might not result in the psychological symptoms commonly experienced by pca patients, but does appear to be related to a distorted perception of the disease's mortal risk. Patients with pca experience reduced psychological well-being, but better understand the risks of pca recurrence and death. Education on the risks and outcomes of pca can help at-risk men to view health assessments with reduced worry.

SCT Promoter Methylation is a Highly Discriminative Biomarker for Lung and Many Other Cancers

Aberrant DNA methylation has long been implicated in cancers. In this work we present a highly discriminative DNA methylation biomarker for non-small cell lung cancers and fourteen other cancers. Based on 69 NSCLC cell lines and 257 cancer-free lung tissues we identified a CpG island in SCT gene promoter which was verified by qMSP experiment in 15 NSCLC cell lines and 3 immortalized human respiratory epithelium cells. In addition, we found that SCT promoter was methylated in 23 cancer cell lines involving >10 cancer types profiled by ENCODE. We found that SCT promoter is hyper-methylated in primary tumors from TCGA lung cancer cohort. Additionally, we found that SCT promoter is methylated at high frequencies in fifteen malignancies and is not methylated in~1000 non-cancerous tissues across >30 organ types. Our study indicates that SCT promoter methylation is a highly discriminative biomarker for lung and many other cancers.

Nonmedical information seeking amid conflicting health information: negative and positive effects on prostate cancer screening

This study investigates the impact of seeking information about the prostate-specific antigen (PSA) test on men's PSA test use during a period of conflicting recommendations. Analyses used longitudinal survey data collected in 2005 and 2006 from a nationally representative sample of U.S. males aged 40-70 years (n = 777). Cross-sectionally, nonmedical information seeking was significantly associated with increased odds of having a PSA test in the past year (Time 1 odds ratio [OR] = 9.74, p < .01, 95% confidence interval [CI] = 4.37, 21.70; Time 2 OR = 5.78, p < .01, 95% CI = 3.17, 10.55). However, lagged analyses showed that among men who had a PSA at Time 1, active seeking is associated with reduced odds of later having a PSA test (OR = 0.33, p < .05, 95% CI = 0.13, 0.85). Participants who had not had a PSA test in the past year very rarely sought information about PSA tests. Information acquisition in an environment of conflicting recommendations may influence adoption of cancer screening behaviors.

Sources of variation in follow-up expenditure after radical cystectomy

BACKGROUND

Follow-up care after radical cystectomy is poorly defined, with extensive variation in practice patterns. We sought to determine sources of these variations in care as well as examine the economic effect of standardization of care to guideline-recommended care.

METHODS

Using linked Surveillance, Epidemiology, and End Results (SEER)-Medicare data from 1992 to 2007, we determined follow-up care expenditures (time and geography standardized) for 24 months after surgery. Accounted expenditures included office visits, imaging studies, urine tests, and blood work. A multilevel model was implemented to determine the effect of region, surgeon, and patient factors on care delivery. We then compared the actual expenditures on care in the Medicare system (interquartile range) with the expenditures if patients received care recommended by current clinical guidelines.

RESULTS

Expenditures over 24 months of follow-up were calculated per month and per patient. The mean and median total expenditures per patient were $1108 and $805 respectively (minimum $0, maximum $9,805; 25th-75th percentile $344-$1503). Variations in expenditures were most explained at the patient level. After accounting for surgeon and patient levels, we found no regional-level variations in care. Adherence to guidelines would lead to an increase in expenditures by 0.80 to 10.6 times the expenditures exist in current practice.

CONCLUSION

Although some regional-level and surgeon-level variations in care were found, the most variation in expenditure on follow-up care was at the patient level, largely based on node positivity, chemotherapy status, and final cancer stage. Standardization of care to current established guidelines would create higher expenditures on follow-up care than current practice patterns.

Time to benefit for colorectal cancer screening: survival meta-analysis of flexible sigmoidoscopy trials

OBJECTIVE

To determine the time to benefit of using flexible sigmoidoscopy for colorectal cancer screening.

DESIGN

Survival meta-analysis.

DATA SOURCES

A Cochrane Collaboration systematic review published in 2013, Medline, and Cochrane Library databases.

ELIGIBILITY CRITERIA

Randomized controlled trials comparing screening flexible sigmoidoscopy with no screening. Trials with fewer than 100 flexible sigmoidoscopy screenings were excluded.

RESULTS

Four studies were eligible (total n = 459,814). They were similar for patients' age (50-74 years), length of follow-up (11.2-11.9 years), and relative risk for colorectal cancer related mortality (0.69-0.78 with flexible sigmoidoscopy screening). For every 1000 people screened at five and 10 years, 0.3 and 1.2 colorectal cancer related deaths, respectively, were prevented. It took 4.3 years (95% confidence interval 2.8 to 5.8) to observe an absolute risk reduction of 0.0002 (one colorectal cancer related death prevented for every 5000 flexible sigmoidoscopy screenings). It took 9.4 years (7.6 to 11.3) to observe an absolute risk reduction of 0.001 (one colorectal cancer related death prevented for every 1000 flexible sigmoidoscopy screenings).

CONCLUSION

Our findings suggest that screening flexible sigmoidoscopy is most appropriate for older adults with a life expectancy greater than approximately 10 years.

Time to benefit for colorectal cancer screening: survival meta-analysis of flexible sigmoidoscopy trials

OBJECTIVE

To determine the time to benefit of using flexible sigmoidoscopy for colorectal cancer screening.

DESIGN

Survival meta-analysis.

DATA SOURCES

A Cochrane Collaboration systematic review published in 2013, Medline, and Cochrane Library databases.

ELIGIBILITY CRITERIA

Randomized controlled trials comparing screening flexible sigmoidoscopy with no screening. Trials with fewer than 100 flexible sigmoidoscopy screenings were excluded.

RESULTS

Four studies were eligible (total n = 459,814). They were similar for patients' age (50-74 years), length of follow-up (11.2-11.9 years), and relative risk for colorectal cancer related mortality (0.69-0.78 with flexible sigmoidoscopy screening). For every 1000 people screened at five and 10 years, 0.3 and 1.2 colorectal cancer related deaths, respectively, were prevented. It took 4.3 years (95% confidence interval 2.8 to 5.8) to observe an absolute risk reduction of 0.0002 (one colorectal cancer related death prevented for every 5000 flexible sigmoidoscopy screenings). It took 9.4 years (7.6 to 11.3) to observe an absolute risk reduction of 0.001 (one colorectal cancer related death prevented for every 1000 flexible sigmoidoscopy screenings).

CONCLUSION

Our findings suggest that screening flexible sigmoidoscopy is most appropriate for older adults with a life expectancy greater than approximately 10 years.

Performance of a multiplexed dual analyte immunoassay for the early detection of non-small cell lung cancer

OBJECTIVES

"PAULA's" test (Protein Assays Utilizing Lung cancer Analytes) is a novel multiplex immunoassay blood test that incorporates both tumor antigens and autoantibodies to determine the risk that lung cancer (LC) is present in individuals from a high-risk population. The test's performance characteristics were evaluated in a study using 380 retrospective clinical serum samples.

METHODS

PAULA's test is performed on the Luminex xMAP technology platform, and detects a panel of 3 tumor antigens (CEA, CA-125, and CYFRA 21-1) and 1 autoantibody marker (NY-ESO-1). A training set (n = 230) consisting of 115 confirmed diagnoses of non-small cell lung carcinoma (NSCLC) cases and 115 age- and smoking history-matched controls was used to develop the LC predictive model. Data from an independent matched validation set (n = 150) was then used to evaluate the model developed, and determine the ability of the test to distinguish NSCLC cases from controls.

RESULTS

The 4-biomarker panel was able to discriminate NSCLC cases from controls with 74% sensitivity, 80% specificity, and 0.81 AUC in the training set and with 77% sensitivity, 80% specificity, and 0.85 AUC in the independent validation set. The use of NY-ESO-1 autoantibodies substantially increased the overall sensitivity of NSCLC detection as compared to the 3 tumor markers alone. Overall, the multiplexed 4-biomarker panel assay demonstrated comparable performance to a previously employed 8-biomarker non-multiplexed assay.

CONCLUSIONS

These studies confirm the value of using a mixed panel of tumor antigens and autoantibodies in the early detection of NSCLC in high-risk individuals. The results demonstrate that the performance of PAULA's test makes it suitable for use as an aid to determine which high-risk patients need to be directed to appropriate noninvasive diagnostic follow-up testing, especially low-dose CT (LDCT).

Reaffirming normal: the high risk of pathologizing healthy adults when interpreting the MMPI-2-RF

Monte Carlo simulations were utilized to determine the proportion of the normal population expected to have scale elevations on the MMPI-2-RF when multiple scores are interpreted. Results showed that when all 40 MMPI-2-RF scales are simultaneously considered, approximately 70% of normal adults are likely to have at least one scale elevation at or above 65 T, and as many as 20% will have five or more elevated scales. When the Restructured Clinical (RC) Scales are under consideration, 34% of normal adults have at least one elevated score. Interpretation of the Specific Problem Scales and Personality Psychopathology Five Scales--Revised also yielded higher than expected rates of significant scores, with as many as one in four normal adults possibly being miscategorized as having features of a personality disorder by the latter scales. These findings are consistent with the growing literature on rates of apparently abnormal scores in the normal population due to multiple score interpretation. Findings are discussed in relation to clinical assessment, as well as in response to recent work suggesting that the MMPI-2-RF's multiscale composition does not contribute to high rates of elevated scores.

Screening tests: a review with examples

Screening tests are widely used in medicine to assess the likelihood that members of a defined population have a particular disease. This article presents an overview of such tests including the definitions of key technical (sensitivity and specificity) and population characteristics necessary to assess the benefits and limitations of such tests. Several examples are used to illustrate calculations, including the characteristics of low dose computed tomography as a lung cancer screen, choice of an optimal PSA cutoff and selection of the population to undergo mammography. The importance of careful consideration of the consequences of both false positives and negatives is highlighted. Receiver operating characteristic curves are explained as is the need to carefully select the population group to be tested.

Multicolor imaging of cancer cells with fluorophore-tagged aptamers for single cell typing

The discrimination of the type of cancer cells remains challenging due to the subtle differences in their expression of membrane receptors. In this work, we developed a multicolor cell imaging method for distinguishing the type of cancer cells with fluorophore-tagged aptamers. We found that the interaction between aptamers and cancer cells was affected by both of the sequence of aptamers and the labeled dyes. As the co-ownership of biomarkers for different cancer cell lines, the fluorophore-tagged aptamers interacted with different cancer cell lines in different degree, resulting in a distinct color to discriminate the type of cancer cells at single cell level. Taking advantage of the cross-reactive ability of the fluorophore-tagged aptamers, we could not only distinguish the cancerous cells quickly from large quantities of noncancerous cells, but also identify the type of the cancerous cells. This work has potential application for cancer diagnostic and therapy in the future.