Long-term outcomes of upfront surgery for magnetic resonance imaging-defined T3 rectal cancer with uninvolved circumferential resection margin

Background: The role of upfront surgery in magnetic resonance imaging-defined cT3 rectal cancer with uninvolved circumferential resection margin (mrCRM) remains debatable despite increasing evidence from MERCURY, OCUM, and QuickSilver. We evaluated long-term oncologic and survival outcomes of this approach. Materials and Methods: This single-center cohort included 144 patients with cT3a–cT3c rectal adenocarcinoma ≤12 cm from the anal verge, negative extramural vascular invasion (EMVI), and uninvolved mrCRM who underwent curative resection between January 2018 and April 2022. All patients were evaluated by multidisciplinary team (MDT) consultation. Only patients with at least 36 months follow-up were analyzed. The endpoints included local recurrence (LR), distant metastasis (DM), overall survival (OS), and disease-free survival (DFS). Results: During a median follow-up interval of 56 months, IQR, 42.75–68, a total of 7 patients (4.9%) had LR and 15 (10.4%) had DM. The 3-, 5-, and 7-year cumulative LR rates were 3.6%, 5.3%, and 5.3% (p = 0.97, stage II vs. III). Corresponding DM rates were 8.5%, 11.6%, and 11.6%, significantly higher in stage III (p = 0.009). OS at 3, 5, and 7 years was 94.4%, 88.2%, and 78.9% (p = 0.13), while DFS was 87.5%, 82.3%, and 78.8% (p = 0.056). Conclusions: Among patients with cT3a/b/c rectal cancer, negative EMVI, and uninvolved mrCRM, upfront laparoscopic surgery yielded encouraging oncologic and survival outcomes. These findings support surgery-first as a viable option in high-volume centers with structured MDT programs, and may be particularly relevant in settings with limited radiotherapy access.