Colorectal Cancer Screening at Younger Ages: A Multicutoff Analysis of FIT Performance

Area of Science:

• Gastroenterology
• Oncology
• Preventive Medicine

Background:

• Rising incidence of early-onset colorectal cancer (CRC) prompts consideration of lowering screening age.
• Limited data exists on the diagnostic performance of fecal immunochemical tests (FIT) in younger populations.
• Assessing FIT performance in individuals aged 55 or younger is crucial for adapting screening strategies.

Purpose of the Study:

• To evaluate the diagnostic performance of FIT for detecting advanced neoplasia (AN) in individuals aged 55 or younger.
• To analyze FIT performance across various fecal hemoglobin (Hb) concentration cutoffs.
• To inform the optimization of CRC screening effectiveness and cost-efficiency in younger demographics.

Main Methods:

• A cross-sectional study of 1724 participants aged 55 or younger who underwent screening colonoscopy.
• Fecal Hb concentrations were measured using FIT (Sentinel FOB Gold) prior to colonoscopy.
• FIT performance metrics (positivity rate, sensitivity, specificity, PPV, NPV) were evaluated at different Hb thresholds.

Main Results:

• Advanced neoplasia (AN) was detected in 8.1% of participants, including 0.3% with CRC.
• At the recommended cutoff (17 µg Hb/g stool), FIT sensitivity was 26.6% and specificity was 94.0% for AN detection.
• Performance metrics varied significantly across different Hb cutoffs, with men showing higher prevalence and detection rates.

Conclusions:

• The study provides detailed quantitative data on FIT's diagnostic performance in a younger CRC screening population.
• Findings can inform and optimize the effectiveness and cost-efficiency of CRC screening at younger ages.
• Further research may refine FIT utilization for early detection in at-risk younger individuals.