TOPLINE:

In 44 patients with large rectal polyps referred for endoscopic resection, pelvic MRI overstaged tumor depth (T-stage) and nodal status (N-stage) in 38.6% and 2.3% of cases, respectively, potentially leading to unnecessary surgery. Endoscopic resection provided definitive histologic staging and was an effective organ-sparing treatment approach, with no recurrences observed during follow-up.

METHODOLOGY:

• Pelvic MRI is recommended in the initial staging of rectal cancer, but its accuracy may be reduced for large adenomas or after prior manipulation of the lesion because MRI has difficulty distinguishing benign from invasive components.
• Researchers evaluated the accuracy of MRI-based staging among patients with large rectal polyps who were referred for endoscopic resection from 2018 to 2025 at The University of Texas MD Anderson Cancer Center.
• They included 44 patients (mean age, 54.8 years; 70.4% male) who were initially evaluated for large rectal lesions that were judged endoscopically unresectable despite biopsies that did not confirm cancer; they underwent MRI as part of national rectal cancer staging guidelines and, after a multidisciplinary discussion, were referred for diagnostic and staging endoscopic resection as an organ-sparing alternative to surgery.
• Overstaging was defined as assigning an MRI stage higher than the final histopathologic stage, whereas understaging was defined as assigning an MRI stage lower than the final histopathologic stage.

TAKEAWAY:

• Pre-resection MRI categorized 24 lesions (54.5%) as T0/T1, 16 (36.4%) as T2, and four (9.1%) as T3, whereas final histopathologic diagnosis showed five adenomas (11.4%), 21 (47.7%) lesions with high-grade dysplasia, five (11.4%) intramucosal adenocarcinomas, nine (20.5%) pT1 adenocarcinomas, and four (9.1%) pT2 adenocarcinomas.
• Overall, MRI findings were discordant with final histopathologic diagnosis in 47.7% of patients, with MRI overstaging and understaging lesions in 40.9% and 6.8% of patients, respectively; MRI overstaged the T-stage and N-stage in 38.6% and 2.3% of cases, respectively.
• Among 37 patients whose condition was managed without surgery and were followed up for a mean of 22.3 months, no local or metastatic recurrences were detected on endoscopic or oncologic surveillance.

IN PRACTICE:

“The practical implications of this study are that endoscopists and surgeons should consider endoscopic resection in the diagnosis and staging of large rectal polyps in order to avoid unnecessary surgical resection for benign neoplasia without a significant impact in oncological outcomes and allowing for organ preservation in this patient population,” the authors of the study wrote.

SOURCE:

The study was led by Phillip S. Ge, MD, The University of Texas MD Anderson Cancer Center, Houston. It was published online in Gastrointestinal Endoscopy.

LIMITATIONS:

The study was limited by the small sample size, referral-driven patient selection, and the delivery of treatment by an expert resection team at a specialized tertiary cancer center.

DISCLOSURES:

The study did not mention any funding sources. One author reported serving as a consultant for various medical device and health tech companies.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.