Reviews on Recent Clinical Trials - Volume 10, Issue 3, 2015

The randomized PLCO trial was designed to answer four primary questions: does screening for these cancers using often promoted tests reduce cancer-specific mortality? Nearly 155,000 men and women were allocated to screening or usual care arms in a 1:1 ratio under a centralized, secure randomization algorithm at ten competitively selected screening centers nationwide. Screened men received PSA blood tests and digital rectal examinations. Screened women received CA125 blood tests and trans-vaginal ultrasound. Both men and women in the screened arm received anterolateral view chest x-ray and 60 cm flexible sigmoidoscopy. Blood specimens were collected at each screening visit and buccal cell DNA was collected once from the usual care participants. Histology slides were collected for cancer cases. Participants completed a baseline questionnaire covering health and risk factors and a dietary questionnaire. Data collected on standardized machine-readable forms were scanned remotely at screening and laboratory sites utilizing PLCO dedicated, NCI provided and configured computer systems for quality checks, archiving, and analysis. Comprehensive quality assurance was implemented over recruitment, consenting, randomization, screening, data management, records keeping, patient-specific screening results reporting, follow-up, and data analysis. Performance and data quality were monitored on-site and remotely by data edits, site visits, and random record audits. Specially trained and certified professionals performed screening procedures and medical record abstracting. An independent committee of medical specialists reviewed and certified case-specific cause of death. Scientific leadership was provided by NCI Project Officers, PLCO principal investigators, external consultants, and an independent data and safety monitoring board.

Biomedical research cannot succeed without funding, knowledgeable staff, and appropriate infrastructure. There are however equally important but intangible factors that are rarely considered in planning large multidisciplinary endeavors or evaluating their success. The Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial required extensive collaborations between individuals from many fields, including clinicians, clinical trialists, and administrators; it also addressed questions across the spectrum of cancer prevention and control. In this manuscript, we examine the experiences and opinions of trial staff regarding the building of successful relationships in PLCO. We summarize, in narrative form, data collected using open-ended questionnaires that were administered to the National Cancer Institute project officers, coordinating center staff, screening center principal investigators, and screening center coordinators in 2015, about 3 years after publication of the final primary trial manuscript. Trust, respect, listening to others, and in-person interaction were frequently mentioned as crucial to building successful relationships.

There were significant recruitment challenges specific to the PLCO Cancer Screening Trial. Large numbers of participants were to be randomized from ten catchment areas nationwide within time and budgetary constraints. The eligible population was elderly and had to meet health and behavioral thresholds. Informed consent was required to participate and be randomized to screening for three cancers at periodic clinic visits or to a usual care arm that included no clinical visits. Consenting required special efforts to fully explain the trial and its potential scientific benefit to future patients with potentially no benefits but possible harms to PLCO participants. Participation would include continued follow-up for at least 13 years after randomization. Strong collaborative investments were required by the NCI and screening centers (SCs) to assure timely recruitment and appropriate racial participation. A trial-wide pilot phase tested recruitment and protocol follow through at SCs and produced a vanguard population of 11,406 participants. NCI announced the trial nationally in advance of the pilot and followed with an even more intense collaborative role with SCs for the main phase to facilitate trial-wide efficient and timely recruitment. Special efforts to enhance recruitment in the main phase included centralized and local monitoring of progress, cross-linking SCs to share experiences in problem solving, centralized training, substantial additional funding dedicated to recruitment and retention, including specialized programs for minority recruitment, obtaining national endorsement by the American Cancer Society, launching satellite recruitment and screening centers, including minority focused satellites, and adding a new SC dedicated to minority recruitment.

It is imperative to measure the degree of contamination throughout the course of randomized controlled trials, as contamination, the receipt of the intervention arm regimen by control arm participants, can affect trial power. In the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial, contamination was estimated through use of the self-administered Health Status Questionnaire (HSQ) annually to a randomly-selected subset of control arm participants. We examined agreement of selfreport of chest x-ray on the HSQ with clinic records at one of the 10 PLCO screening centers (Henry Ford Health System, or HFHS). We focus on HFHS participants covered by the Health Alliance Plan (HAP), a managed health care insurance plan owned and operated by HFHS, because claims for care received both at HFHS and other facilities are available in HFHS databases for HAP enrollees. We examined agreement for the six years prior to HSQ completion, with HFHS clinic records considered to be the gold standard. For those who had complete HAP coverage during the six years, percent agreement was 0.69, sensitivity was 0.84, and positive predictive value was 0.76. Specificity and negative predicted value were low, however (0.28 and 0.38, respectively), and Cohen’s kappa was 0.13. For groups with incomplete or no HAP coverage, and when timing of exam was considered, performance measures typically became lower, in some instances below 0.20. These data suggest that self-report of chest x-ray screening may not be accurate, although high prevalence of chest x-ray may make performance measures less interpretable.

The most rigorous and accurate approach to evaluating clinical events in cancer screening studies is to use data obtained through medical record abstraction (MRA). Although MRA is complex, the particulars of the procedure—such as the specific training and quality assurance processes, challenges of implementation, and other factors that influence the quality of abstraction—are usually not described in reports of studies that employed the technique. In this paper, we present the details of MRA activities used in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, which used MRA to determine primary and secondary outcomes and collect data on other clinical events. We describe triggers of the MRA cycle and the specific tasks that were part of the abstraction process. We also discuss training and certification of abstracting staff, and technical methods and communication procedures used for data quality assurance. We include discussion of challenges faced and lessons learned.

Death review was conducted for the Prostate, Lung, Colorectal and Ovarian (PLCO) cancer screening trial to avoid the biases associated with causes of death entered on death certificates. An algorithm selected deaths for review. Records on diagnosis and terminal illness were perused in the coordinating center and by the chair of the death review committee (DRC). Identifying information and randomization arm was removed. Three reviewers independently determined the cause of death. Disagreement was resolved at a meeting of the DRC. This process was subsequently simplified. The cause of death was determined by one DRC member and compared to the death certificate. With agreement the case was finalized. When discordant, the records were sent to a second DRC member. If the reviewers agreed, the case was finalized. If not, a third member reviewed. If two of the three reviewers agreed, the case was sent back to the discordant reviewer. If the reviewer remained discordant the case was resolved by a conference call. Of the 4728 death reviews that were completed, the DRC confirmed the death certificate underlying cause for over 90%. Between 5% and 13% of the certified deaths were regarded as indirect causes of death, associated with the treatment of the ascertained cancer; differential for prostate cancer, 11% in the intervention arm and 6% in the control. Without review, between 1% and 6% of the deaths that occurred would not have been assigned to the relevant PLCO cancer. The DRC completed 76% of those requiring review before the process ceased.

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. In addition, formalin-fixed paraffin embedded tumor tissue specimens were collected for participants in both arms for selected cancer sites. Collection of biospecimens at multiple timepoints (i.e. serial samples) and prior to cancer diagnosis, paired with rich epidemiologic and screening data, makes the PLCO collection of biospecimens a uniquely valuable resource. As such, access to the PLCO biorepository is granted to investigators by a rigorous scientific review process and guided by a steering committee which is responsible for developing and implementing the biospecimen use policies. Here, we describe the procedures for biospecimen collection, processing, storage, requisition, and distribution, as well as data management employed in PLCO. We also provide examples of how the biospecimens have been used to advance cancer research and describe relevant lessons learned to help inform cohorts wishing to add or modify biospecimen collection.

The NCI imbedded the notion of comprehensive quality control and assurance (CQA) in the design concept for the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. PLCO implemented a comprehensive, adaptable quality assurance and control program to span more than 20 years of data collection, coordinate multiple institutions and committees, and integrate a wide variety of complex protocols. CQA concepts, practices, and procedures traced through all aspects of trial management, governance, and operations of PLCO. The driving force behind CQA in PLCO was scientific and clinical credibility of trial data and findings. CQA as implemented in PLCO was operationally analogous to the concept of Total Quality Management (TQM) described in the management literature. This paper describes CQA actualization in PLCO.

The Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial was a large, randomized controlled trial of cancer screening that also evolved over time into a unique epidemiologic cohort. Vast quantities of data have been collected since the beginning of the trial in 1993. Screening data was obtained through 2006. Questionnaire-based risk factor data (collected at baseline and at other points in the trial), vital status, cancer diagnoses and treatment, biospecimen data and additional ancillary efforts continue to be collected. Accurate data collection and efficient management methods are required to ensure high-quality data and valid and consistent analyses of trial outcomes. Information Management Services (IMS) was and continues to be responsible for processing and converting the collected raw PLCO data into comprehensive and accessible datasets. IMS also continues to provide a wide spectrum of analytic support including support for trial monitoring, data sharing, and epidemiologic research. In this paper, we describe the data processing and management requirements from the analytic team perspective, highlighting the various data sources and their complexity. We also illustrate the construction of usable analytic data files and discuss the wide range of analytic support provided. Instructions for accessing PLCO data also are provided.

The Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO), a large-scale, multi-institutional, randomized controlled trial, was launched in 1992 to evaluate the effectiveness of screening modalities for prostate, lung, colorectal, and ovarian cancer. However, PLCO was additionally designed to serve as an epidemiologic resource and the National Cancer Institute has invested substantial resources over the years to accomplish this goal. In this report, we provide a summary of changes to PLCO’s follow-up after conclusion of the screening phase of the trial and highlight recent data and biospecimen collections, including ancillary studies, geocoding, administration of a new medication use questionnaire, consent for linkage to Medicare, and additional tissue collection that enhance the richness of the PLCO resource and provide further opportunities for scientific investigation into the prevention, early detection, etiology and treatment of cancer.

Cachexia is one of the most common manifestations in advanced cancer patients, but too often it remains under- recognized and under-treated. Starvation is not the same of cachexia. Cachexia is defined by “weight loss >5% over past 6 months in absence of simple starvation or the combination of ongoing weight loss>2% with BMI <20 or sarcopenia”. The pathogenesis of cancer cachexia is not fully understood, but inflammation and an increased catabolic response to a number of cancer-related factors seem to represent the basis of any assumption. Early diagnosis of a pre-cachectic or cachectic state is a key moment for the treatment of this complex syndrome, in order to guarantee an adequate food intake and suitable exercise and to interfere with the inflammatory processes that are typical of cachexia. Therefore, one of the main aims is to identify those patients most likely to develop the syndrome early. A multimodality baseline approach to cancer cachexia addresses reversible clinical contributory factors. There are currently no medicinal products that have a proven efficacy in the medical approach to cancer cachexia. Recently, anamorelin, a synthetic orally active ghrelin receptor agonist, showed promising results, but the best approach to cancer cachexia probably remains an early multimodal interventions consisting in nutritional intervention, exercise and rehabilitation program, and multi-target drug therapies. This review summarizes what we know and what still need to know about cancer cachexia syndrome.