GWAS Explorer: an open-source tool to explore, visualize, and access GWAS summary statistics in the PLCO Atlas.

The Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial is a prospective cohort study of nearly 155,000 U.S. volunteers aged 55-74 at enrollment in 1993-2001.

Data sharing in clinical trials: An experience with two large cancer screening trials.

Paul Pinsky of the US National Cancer Institute and colleagues describe the implementation and outcomes of web-based data sharing from the PLCO and NLST cancer screening trials.

The Prostate, Lung, Colorectal and Ovarian Cancer (PLCO) Screening Trial Pathology Tissue Resource.

Background: Pathology tissue specimens with associated epidemiologic and clinical data are valuable for cancer research. The Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial undertook a large-scale effort to create a public resource of pathology tissues from PLCO participants who developed a cancer during the trial.

Methods: Formalin-fixed paraffin-embedded tissue blocks were obtained from pathology laboratories on a loan basis for central processing of tissue microarrays, with additional free-standing tissue cores collected for nucleic acid extraction.

The PLCO Biorepository: Creating, Maintaining, and Administering a Unique Biospecimen Resource.

Inclusion of biospecimens in population-based studies is an integral part of understanding disease etiology, identifying biomarkers and developing prevention and treatment strategies. The Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening trial collected, processed and stored biospecimens from participants to create a biorepository of specimens which serves as a useful resource for a broad research community. PLCO collected blood samples from consented screening arm participants at six screening rounds and a buccal sample from consented control arm participants.

Lung cancer risk by years since quitting in 30+ pack year smokers.

Objective: Current United States recommendations for low-dose computed tomography (LDCT) lung cancer screening limit eligibility to ever-smokers with 30+ pack-years, with former smokers eligible only within 15 years of quitting. The 15 year limit is partly based on perceived decreases in lung cancer risk as years since quitting (YSQ) increase. We examine the relationship between lung cancer risk and YSQ among 30+ pack-year former smokers.

Laboratory detective work identifies a mishandling problem in sample aliquoting.

Data from a recent ovarian cancer biomarker study using serum aliquots from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial Biorepository showed that CA125II concentrations in these aliquots were significantly lower than those previously measured in the same subjects from the same blood draw. We designed an experiment to investigate whether samples used in the study (reference study) were compromised during the aliquoting process. We measured CA125II in the "sister" vials created during the same aliquoting process as the reference study aliquot, and in "cousin" vials newly aliquoted from another parent vial from the same blood draw, from 15 healthy controls in the study.

The prostate, lung, colorectal, and ovarian cancer screening trial and its associated research resource.

The Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial is a large-scale research effort conducted by the National Cancer Institute. PLCO offers an example of coordinated research by both the extramural and intramural communities of the National Institutes of Health. The purpose of this article is to describe the PLCO research resource and how it is managed and to assess the productivity and the costs associated with this resource.

Potential effect of the risk of ovarian cancer algorithm (ROCA) on the mortality outcome of the Prostate, Lung, Colorectal and Ovarian (PLCO) trial.

Recently, the Prostate, Lung, Colorectal and Ovarian (PLCO) Trial reported no mortality benefit for annual screening with CA-125 and transvaginal ultrasound (TVU). Currently ongoing is the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS), which utilizes the risk of ovarian cancer algorithm (ROCA), a statistical tool that considers current and past CA125 values to determine ovarian cancer risk. In contrast, PLCO used a single cutoff for CA125, based on current levels alone.

Building multi-marker algorithms for disease prediction-the role of correlations among markers.

A widely held viewpoint in the field of predictive biomarkers for disease holds that no single marker can provide high enough discrimination and that a panel of markers, combined in some type of algorithm, will be needed. Motivated by a recent study where 27 additional markers for ovarian cancer, many of which had good predictive value alone, failed to substantially increase the predictive ability of the primary marker of CA125, we explore the effect of additional markers on the area under the ROC curve (AUC). We develop a statistical model based on the multivariate normal distribution and linear algorithms and use it to explore how the magnitude and direction of statistical correlation among the markers (in diseased and in non-diseased) is critical in determining the added predictive value of additional markers.

Effect of screening on ovarian cancer mortality: the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Randomized Controlled Trial.

Context: Screening for ovarian cancer with cancer antigen 125 (CA-125) and transvaginal ultrasound has an unknown effect on mortality.

Objective: To evaluate the effect of screening for ovarian cancer on mortality in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial.

Design, Setting, And Participants: Randomized controlled trial of 78,216 women aged 55 to 74 years assigned to undergo either annual screening (n = 39,105) or usual care (n = 39,111) at 10 screening centers across the United States between November 1993 and July 2001.

Biospecimen reporting for improved study quality (BRISQ).

Human biospecimens are subject to a number of different collection, processing, and storage factors that can significantly alter their molecular composition and consistency. These biospecimen preanalytical factors, in turn, influence experimental outcomes and the ability to reproduce scientific results. Currently, the extent and type of information specific to the biospecimen preanalytical conditions reported in scientific publications and regulatory submissions varies widely.

Biospecimen reporting for improved study quality (BRISQ).

Human biospecimens are subjected to collection, processing, and storage that can significantly alter their molecular composition and consistency. These biospecimen preanalytical factors, in turn, influence experimental outcomes and the ability to reproduce scientific results. Currently, the extent and type of information specific to the biospecimen preanalytical conditions reported in scientific publications and regulatory submissions varies widely.

A framework for evaluating biomarkers for early detection: validation of biomarker panels for ovarian cancer.

A panel of biomarkers may improve predictive performance over individual markers. Although many biomarker panels have been described for ovarian cancer, few studies used prediagnostic samples to assess the potential of the panels for early detection. We conducted a multisite systematic evaluation of biomarker panels using prediagnostic serum samples from the Prostate, Lung, Colorectal, and Ovarian Cancer (PLCO) screening trial.

Ovarian cancer biomarker performance in prostate, lung, colorectal, and ovarian cancer screening trial specimens.

Establishing a cancer screening biomarker's intended performance requires "phase III" specimens obtained in asymptomatic individuals before clinical diagnosis rather than "phase II" specimens obtained from symptomatic individuals at diagnosis. We used specimens from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial to evaluate ovarian cancer biomarkers previously assessed in phase II sets. Phase II specimens from 180 ovarian cancer cases and 660 benign disease or general population controls were assembled from four Early Detection Research Network or Ovarian Cancer Specialized Program of Research Excellence sites and used to rank 49 biomarkers.