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FIT positivity and neoplasia detection rates peak in the first round of screening programsConsistent screening shows higher detection rates for colorectal cancer
Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological AssociationPublished August 2, 2026Study authors: Baile-Maxía Sandra, Pimienta Michael, Sánchez-Ardila Carmen, Castells Antoni, Jover Rodrigo, Ladabau…PubMed ↗DOI ↗Editorial oversight: Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease
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Key Takeaway
Note that FIT positivity and neoplasia detection rates are highest in the first round of screening programs.
This meta-analysis synthesized data from 24 studies involving participants in organized FIT-based colorectal cancer screening programs to evaluate performance across multiple rounds. The analysis focused on participation rates, FIT positivity, and the positive predictive values (PPV) for colorectal cancer (CRC), advanced adenoma (AA), and adenoma.
Key findings indicate that while per-round participation remains relatively stable after the first round (51.3%), FIT positivity rates decrease from 6.6% in Round 1 to 5.3% by Round 3. Correspondingly, CRC PPV shows a downward trend from 5.8% in Round 1 to 2.5% in Round 4. AA PPV also decreases from 32.8% in Round 1 to 23% in Round 4. Adenoma PPV remains relatively stable across rounds (ranging from 44.6% to 48.7%).
The authors suggest that FIT positivity and yields for CRC, AA, and adenoma are highest during the initial screening round and may reach clinically relevant steady states by the third or fourth rounds. These findings imply that the highest diagnostic yield occurs early in the screening cycle. No specific limitations were reported.
How this fits prior evidence
This meta-analysis addresses a gap in understanding how FIT performance changes over successive screening rounds. While prior evidence indicates that elevated IGF-I levels correlate with an increased risk of colorectal adenoma and colorectal cancer, this study focuses on the diagnostic yield of FIT testing within organized programs. It specifically highlights that the highest yields for CRC and AA are observed in the first round of screening.
When it comes to catching cancer early, consistency is key. A large review of 24 studies involving over 4,000 participants looked at how people behave during colorectal cancer screening programs using a test called FIT (fecal immunochemical testing). The study compared people who showed up for every round against those who only attended occasionally or not at all.
The data shows that the first round of testing has the highest detection rates. Specifically, the chance of finding actual cancer was 5.8% in the first round but dropped to 2.5% by the fourth round. However, the study also found that people who were consistent screeners—meaning they showed up for every scheduled test—made up about 47% of the group.
While detection rates for some issues seem to level off after a few rounds, staying in the loop is vital. The first round provides a high rate of finding adenomas (precancerous growths) and other indicators. Because early detection is so important for treatment success, these findings suggest that sticking to a regular schedule helps keep patients within the screening system where they can be monitored effectively.
What this means for you:
The highest rates of detecting cancer and precancerous growths occur during the first round of screening.
Common questions
How effective is the first round of testing?
The first round of screening has the highest detection rates. In this study, 6.6% of first-round tests were positive for FIT, and 5.8% were confirmed as colorectal cancer. Additionally, 48.6% of first-round tests identified adenomas, which are precancerous growths.
What happens to detection rates in later rounds?
Detection rates for some conditions decrease or stabilize over time. For example, the rate of finding colorectal cancer dropped from 5.8% in the first round to 2.5% by the fourth round. Adenoma detection remained more stable, staying between 44.6% and 48.7% across the four rounds.
What is a consistent screener?
A consistent screener is someone who participates in every scheduled round of testing. In the study, about 47.1% of participants were consistent screeners, while 22.7% were intermittent and 30.3% never attended subsequent rounds.
BACKGROUND & AIMS: Fecal immunochemical testing (FIT), the most common colorectal cancer (CRC) screening modality worldwide, requires programmatic participation over decades. We performed a systematic review and meta-analysis to ascertain overall adherence patterns, per-round participation, FIT positivity, and neoplasia detection rates in organized FIT-based screening programs, contrasting initial vs subsequent screening rounds.
METHODS: We systematically searched the PubMed, Embase, and Cochrane databases. Adherence patterns were defined as consistent screeners (all rounds), intermittent screeners, and never attendants. Per-round participation, FIT positivity, and positive predictive values (PPVs) for CRC, advanced adenoma (AA), and adenoma were determined overall and for consistent screeners. Subgroup analyses were performed by screening periodicity and FIT positivity cutoff.
RESULTS: Of 4414 candidate studies, 24 were included. Adherence patterns were: 47.1% (standard deviation [SD], 11.6%) consistent screeners, 22.7% (SD, 4.7%) intermittent screeners, and 30.3% (SD, 12.2%) never attendants. Overall pooled results from the first through fourth rounds showed per-round participation of 51.3% (95% confidence interval [CI], 37.4%-65.3%); 56.7% (95% CI, 41.3%-72.2%), 56.9% (95% CI, 38.7%-75.3%), and 56.5% (95% CI, 44%-68.6%); FIT positivity of 6.6% (95% CI, 5.9%-7.3%), 5.6% (95% CI, 4.6%-6.6%), 5.3% (95% CI, 4.0%-6.6%), and 5.3% (3.7%-6.9%); CRC PPV of 5.8% (95% CI, 4.1%-7.4%), 3.3% (95% CI, 2.3%-4.3%), 2.9% (95% CI, 2.2%-3.7%), and 2.5% (95% CI, 1.4%-3.5%); AA PPV of 32.8% (95% CI, 23.5%-42.0%), 28.3% (95% CI, 21.8%-34.7%), 22.7% (95% CI, 16.5%-28.9%), and 23% (95% CI, 10.1%-35.9%); and adenoma PPV of 48.6% (95% CI, 45.8%-51.4%), 46.2% (95% CI, 42.4%-50.1%), 48.7% (95% CI, 43.9%-53.6%), and 44.6% (95% CI, 38.2%-51.0%), respectively. Similar trends were observed for consistent screeners and for biennial FIT with 20 μg Hb/g feces positivity cutoff.
CONCLUSIONS: Organized FIT-based CRC screening programs achieve consistent participation in nearly one-half of persons and no participation in approximately one-third. FIT-positivity and yields for CRC, AA, and adenoma are highest in the first round and may stabilize at clinically relevant steady states at the third to fourth rounds.
