Integrated Literature Review on the Management of Positive Doughnut Margins in Low Rectal Cancer Post-neoadjuvant Chemoradiation: Surgical Decision-making and Oncologic Outcomes

Objectives: Low rectal cancer presents dual challenges—achieving oncologic radicality while preserving sphincter function. Neoadjuvant chemoradiation (NACRT) has become the cornerstone of treatment, yet it induces significant histological changes that complicate intraoperative assessment of resection margins. This review aims to critically evaluate the management of positive doughnut margins in the context of NACRT. Methodology: A comprehensive literature search was conducted using PubMed, Scopus, and Web of Science databases to identify peer-reviewed articles from January 2015 to May 2025. The keywords included “positive doughnut margin,” “low rectal cancer,” “neoadjuvant chemoradiation,” and “intraoperative frozen section.” Emphasis was placed on surgical decision-making, histopathologic interpretation, and oncologic outcomes. Results: Doughnut specimens obtained during stapled anastomoses represent critical proximal and distal margins. Post-NACRT histological distortion may yield ambiguous frozen section results. While a positive doughnut margin may raise concerns of residual disease and local recurrence, its prognostic significance remains debatable. Current strategies range from re-resection and extended dissection to watchful waiting in select cases. Emerging modalities—such as high-resolution MRI, diffusion-weighted imaging, and molecular profiling—show promise in refining intraoperative decision-making. Conclusion: Positive doughnut margins should not be viewed in isolation but interpreted alongside tumor regression grade, main specimen margins, and patient fitness. A multidisciplinary approach, integrating imaging and pathological cues, is vital. This review provides a practical and evidence-based framework for surgeons managing these complex scenarios while identifying future research directions.