Adenoma detection rate and tolerability of two ultra-low volume bowel preparations in screening: a noninferiority randomized controlled trial

Abstract

The adenoma detection rate (ADR), recognized as a surrogate marker for colorectal cancer incidence and mortality reduction, is closely linked to the efficacy of bowel cleansing. However, there is a dearth of evidence examining the impact on ADR when employing two distinct very low-dose bowel cleansing products. This study sought to compare ADR in a fecal immunochemical occult blood testing (iFOBT) based organized screening program by utilizing 1L polyethylene glycol plus ascorbate (1L-PEGA) versus magnesium citrate plus picosulphate (SPMC), both administered in a split-dose regimen. We conducted a comparative, parallel, randomized, noninferiority, and low-intervention clinical trial, the study targeted individuals from a population colorectal cancer screening program aged 50-69 with a positive iFOBT result scheduled for a work-up colonoscopy in the morning. Participants were randomized to either 1L-PEGA or SPMC for bowel cleansing. Main outcome was ADR. Secondary outcomes were bowel preparation quality, individuals' safety, tolerability and satisfaction. A total of 1,002 subjects were included, 501 in each group. There were no differences between groups with respect to pooled ADR (SPMC, 56.5% [52.1-60.8]; 1L-PEGA, 53.7% [49.3-58.0]; RR 0.95 [0.85-1.06]); therefore, SPMC demonstrated noninferiority in ADR compared to 1L-PEGA (difference, 2.8%; 2-sided 95% lower confidence limit (LCL), -3.4). In addition, there were no significant differences in mean lesions regardless of size and location between arms. Bowel preparation favored 1L-PEGA (96.2% vs. 89.2%; p<0.001) whereas SPMC exhibited significantly higher safety and tolerability, as evidenced by fewer non-serious treatment-emergent adverse events CONCLUSIONS: SPMC emerged as a noninferior laxative compared to 1L-PEGA concerning ADR. Despite the superior bowel preparation quality associated with 1L-PEGA, the safety, tolerability and overall satisfaction of participants were higher with SPMC. This trial was registered at ClinicalTrials.gov (EudraCT: 2019-003186-18) on March 18, 2019.