Despite the convenience of at-home screening tests for early detection of colorectal cancer (CRC), a study led by UT Southwestern Medical Center researchers examining more than a decade of patient data found that about 10% of the tests could not be processed, mostly due to patient error.

The findings, published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research, provide critical insights into challenges that patients have collecting a specimen, properly labeling samples, and completing follow-up tests in a timely manner.

“The study underscores the importance of addressing breakdowns in the screening process, particularly in specimen collection and labeling,” says corresponding author Rasmi Nair, MBBS, MPH, PhD, assistant professor in the Peter O’Donnell Jr. School of Public Health at UT Southwestern. “Understanding and mitigating barriers to successful colorectal cancer screening is critical for improving CRC outcomes.”

Nair co-led the research with Po-Hong Stuart Liu, MD, MPH, Clinical Research Fellow in the Division of Digestive and Liver Diseases at UT Southwestern.

The at-home tests for CRC are often more convenient, less costly, and less invasive than a colonoscopy or other stool-based tests.

Colorectal Study Results

This retrospective study analyzed at-home fecal immunochemical tests (FIT) submitted between 2010 and 2019 from 56,980 individuals who had a primary care visit through Parkland Health in the year prior to the test. Parkland Health is a safety net hospital system in Dallas County and UT Southwestern’s primary teaching hospital. Patients of average CRC risk between ages 50 and 74 were included in the analysis to determine the rates of unsatisfactory FITs and subsequent follow-up testing.

Nair and her team discovered that more than 10% of FIT samples could not be processed in the laboratory; that rate is double the 5% recommended threshold set by the U.S. Multi-Society Task Force on Colorectal Cancer. Inadequate specimen collection (51%), incomplete labeling (27%), age of specimen (13%), and broken or leaking containers (8%) were the primary causes of failed tests. The study also found higher failure rates among patients who were male, Black, or Spanish-speaking, or on Medicaid. Additionally, patients who received kits in the mail rather than from a practitioner were at greater risk of test failure.

Researchers advocate for more robust patient education strategies, better test-tracking procedures, and timely follow-up of problem tests to reduce FIT failure rates and improve patient care through early CRC interventions. Researchers also anticipate that their findings will boost the effectiveness of other at-home testing services. 

Further reading: Strategic Collaboration Aims to Bring Advanced Colorectal Cancer Screening to U.S.

“Our findings could impact other at-home tests such as fecal DNA tests for CRC screening and future home testing for human papillomavirus, for instance,” Nair says. “Understanding the reasons for unsatisfactory home tests, implementing automatic ordering of subsequent tests, and ensuring appropriate completion of tests and follow-up become increasingly important.” 

Other UTSW researchers who contributed to this study were Celette Sugg Skinner, PhD, Professor in the O’Donnell School of Public Health and a member of the Harold C. Simmons Comprehensive Cancer Center; Noel Santini, MD, MBA, Clinical Associate Professor of Internal Medicine at UT Southwestern and Vice President and Senior Medical Director of Ambulatory & Population Medicine at Parkland Health; and Cynthia Ortiz, MPH, Ellen Hu, MHS, and Jacquelyn M. Lykken, PhD, all with the O’Donnell School of Public Health.

This study was funded by grants from the National Institutes of Health (U54 CA163308, UM1 CA222035, and T32 DK007745) and the Cancer Prevention and Research Institute of Texas (PP160075).

Featured image: Rasmi Nair, MBBS, MPH, PhD, assistant professor in the Peter O’Donnell Jr. School of Public Health at UT Southwestern. Photo: UT Southwestern.