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.
This retrospective study looked at in-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.
The 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.