Distinct prognostic impact of circumferential resection margin and adverse histologic features after intersphincteric resection for ultra-low rectal cancer following chemoradiotherapy: a retrospective cohort study
Year: 2026
Type: article
Study design: Observational Study
Abstract: Purpose: Circumferential resection margin (CRM) involvement after intersphincteric resection (ISR) is uncommon but clinically important. We evaluated the association of CRM status and adverse histopathologic features with recurrence after ISR following neoadjuvant concurrent chemoradiotherapy (CCRT). Methods: From 2011 to 2022, 520 patients underwent ISR for ultra-low rectal cancer (≤3 cm from the anal verge) at a single tertiary center. Among them, 326 who received CCRT were analyzed. Clinicopathologic variables were evaluated in relation to disease-free survival (DFS), local recurrence-free survival (LRFS), and distant recurrence-free survival (DRFS). Multivariable Cox regression evaluated adjusted associations. Results: 85.8%, P = 0.299). After adjustment, CRM involvement remained associated with LRFS (hazard ratio [HR], 9.419; P < 0.001) and DFS (HR, 3.612; P = 0.017). Perineural invasion was associated with all recurrence endpoints. Conclusion: CRM involvement was associated predominantly with poorer local control after ISR following CCRT, whereas adverse microscopic features, particularly perineural invasion, showed broader associations with both local and distant recurrence. The combined assessment of CRM status and microscopic tumor invasiveness may therefore provide complementary prognostic information after ISR for ultra-low rectal cancer.
Institutions: Samsung Medical Center, Sungkyunkwan University
Language: English
Subfield: Oncology
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W7221645369