# Evaluating quality indicators in colorectal cancer screening via fecal immunochemical tests: a five-year study from a developing country

## TL;DR

A five-year study in Iran evaluated colorectal cancer screening quality using fecal immunochemical tests and found key risk factors and detection rates.

## Contribution

This study provides the first detailed analysis of CRC screening quality indicators in a developing country with a transitioning lifestyle and new screening programs.

## Key findings

- Adenoma detection rates were 25.3%, with higher risks in men and those aged 60–69.
- Bowel preparation quality was better in private centers and among patients with BMI < 30.
- Polyp detection rates were higher in public centers and among academic groups.

## Abstract

Assessing quality indicators in colorectal cancer (CRC) screening via the fecal immunochemical test (FIT) is crucial. However, data on developing countries with lower CRC rates, lifestyle transitions, newly established screening programs, and no consensus on optimal targets are scarce.

This analysis evaluated 2,209 average-risk individuals aged 50–70 years in Iran between 2017 and 2022. The polyp detection rate (PDR), adenoma detection rate (ADR), sessile serrated lesion detection rate (SDR), and adenomas per colonoscopy (APC) were calculated. Patient relationships with the center, colonoscopist, bowel preparation, and comorbidities were assessed. Additionally, potential risk factors for bowel preparation quality were examined.

The analysis revealed a PDR of 34.5%, an ADR of 25.3%, an advanced ADR of 10%, a proximal ADR of 13.0%, an SDR of 1%, and a CRC rate of 2.7%. After adjustment, adenoma risk was greater in men (OR 1.84; 95% CI 1.49–2.69; p < 0.01) and those aged 60–69 (OR 1.28; 95% CI 1.04–1.58; p = 0.02), with similar trends for other detection rates. Polyps but not adenomas were more common in public centers (OR 1.28; 95% CI 1.04–1.57; p = 0.02) and among the academic group (OR 1.34; 95% CI 1.07–1.68; p = 0.01). PDR and APC were higher in colonoscopies with cecal intubation (p < 0.05). Bowel preparation quality was higher in private centers, with academic physicians, and among patients with a BMI < 30 (p < 0.05).

The results provide early evidence of proposed ADR targets in developing countries. Given that the ADR depends on background epidemiology, implementing a dynamic, standard living point system based on extensive data is crucial. We recommend updating physicians on screening guidelines, prioritizing men, older adults, diabetic patients, and obese individuals.

The online version contains supplementary material available at 10.1186/s12876-025-04527-1.