In 1993, the University of Utah was selected as one of ten sites to be a study center for the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO). Designed and sponsored by the National Cancer Institute (NCI), the study’s purpose was to determine the impact of preventive screening on cancer-related mortality and other related outcomes in men and women aged 55 to 74. For more than 30 years, study sites recruited participants, conducted screenings, and collected data.
The Department of Family & Preventive Medicine (DFPM) contributed heavily to the PLCO trial, with two of its employees supporting the trial since its inception: Division of Public Health Professor Lisa Gren, PhD, and Grant & Contract Officer Anne Randall. Fulfilling her desire to be involved in human research, Dr. Gren joined the PLCO trial after completing a Master of Science in Public Health as its original study coordinator under the leadership of then principal investigator Saundra S. Buys, MD, while Randall was brought on to support the participant recruiting process.
Motivation behind the research
The rationale behind the trial is deceptively simple, as it follows the observation that screening can be an effective way to prevent cancer through early detection and intervention. However, not all screening methods are equally effective, and if a particular screening process fails to reduce mortality, it provides the opportunity to discard ineffective methods and explore alternative options.
“This approach can be challenging to advocate for in the prevention field, as early detection and treatment seem inherently logical. Nonetheless, side effects must be considered,” said Gren. The PLCO trial examined the balance between benefits and risks to inform decision-making in the screening process.
Power of collaboration
As part of the study, DFPM’s PLCO team traveled across Utah and surrounding states—visiting places such as Boise, Idaho; Winnemucca, Nevada; and Evanston, Wyoming—on recruitment trips. “It was a lot of work, and it took many hands to recruit participants,” said Randall recalling the number of DFPM faculty, staff, and graduate students who contributed to the PLCO trial over the years. . Several current and former faculty members also provided leadership and support for the study, including Public Health Associate Professor Karen Schliep, PhD; Occupational and Environmental Health Division Chief Jeremy Biggs, MD; Internal Medicine Clinical Assistant Professor Neil Argyle, MD; and Pharmacy Clinical Associate Professor Kyle Turner, PharmD.
In the beginning, the study’s scope was relatively modest, but in 2009, the NCI decided to expand data collection on PLCO participants beyond the initial study design to better track cancer outcomes and mortality. “What kept the trial going for so long is the amazing group of participants who were willing to answer questions for us,” said Gren. “In addition to studying cancer screening, we were able to begin looking at what contributes to people living longer and healthier lives.”
Outcomes of the trial
The data from the PLCO trial has been utilized by researchers around the world and has helped advance our understanding of cancer, including who gets cancer, the impact of identifying cancer early, and the factors that can help people live longer after being diagnosed.
One of the key findings of the trial was that colorectal cancer screening significantly reduced the incidence of colon cancer, confirming its effectiveness in preventing cancer and decreasing mortality through early detection and intervention. This finding is important, as colorectal cancer screening presents a unique challenge for healthcare providers: although the screening is highly effective, many people are reluctant to undergo screening. Understanding the correlation between screening and prevention allows public health experts to focus on making the exam less invasive and educating individuals on the importance of screening.
With the average age of colorectal cancer diagnosis getting younger every year, education is more important than ever. “It certainly highlights this ongoing nature of science and development. There’s a technology piece, a human interaction piece, and a changing dynamic of who colorectal cancer affects and when it affects them,” said Gren. While the PLCO findings fall within the public health sphere, the application of its findings extends into clinical practice, as providers work to promote and provide screening in ways that foster positive health outcomes. “This is an ongoing problem that researchers around the world are looking to solve,” she said.
The colorectal cancer findings are just one portion of the impact of the PLCO. With more than 1,000 scientific papers published using data from the study, PLCO has become a landmark study that is actively shaping cancer screening guidelines in the United States and worldwide.
Personal reflections
For Gren, the most gratifying parts of the study were its longevity and the opportunity to collaborate with a dedicated team. The complexity of managing extensive multi-site studies fostered the development of a team known for its cohesiveness and detailed work. “We learned from each other’s strengths and worked so well together that other research teams often sought our insights,” she said.
This experience also taught Gren essential skills in organizing and managing clinical trials, which she has since applied to numerous research projects throughout her career. She has now become a resource for others, publishing several papers on conducting effective large-scale studies. “If it hadn’t been for the PLCO trial, I don’t know if I would have ever worked in this area of science,” she said.
Randall echoed Gren’s thoughts on working with a committed team and how the experience helped shape her career. “It’s been nothing but a pleasure to work on this project,” said Randall. “I never thought I would be working in the health sciences field, and PLCO really kicked off my career at the University of Utah.”
While Randall’s and Gren’s work on the PLCO trial has significantly advanced their professional endeavors, resulting in numerous papers, projects, and new career opportunities, the most important outcome of the study is its potential to reduce cancer diagnoses and mortality among the population. “Whether it’s us personally or our family and friends, we’ve all been impacted by cancer,” said Randall. Through dedicated public health research projects like PLCO, we strive to envision a future where the effects of cancer are significantly reduced and no longer a common part of the human experience.