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Grand RoundsWeekly Evidence Brief

Colorectal Surgery

Edition

30-Second Takeaway

  • Delayed surgery for adhesive SBO increases early mortality and bowel resection, while early, often laparoscopic, surgery cuts recurrence.
  • FOLFOXIRI/bevacizumab plus nivolumab shows high activity in RAS/BRAF-mutated mCRC but with frequent grade ≥3 toxicity.
  • Blood ctDNA screening and variable FIT cutoffs will change which CRC and advanced lesions reach surgeons.

Week ending March 28, 2026

Adhesive SBO timing, CRC screening shifts, and perioperative oncology choices for colorectal surgeons

Delayed surgery for adhesive small bowel obstruction increases early mortality and long-term recurrence

ANNALS OF SURGERYMar 27, 2026

This nationwide French cohort evaluated 71,573 surgically treated adhesive small bowel obstruction episodes by time from admission to operation. Thirty-day mortality rose from 3.6% with surgery on days 0–1 to 7.1% when surgery occurred on or after day 9. Bowel resection rates also increased with delay, from 18.0% for early surgery to 24.5% with the latest operations. Long term, recurrence occurred in 23.5% of nonoperatively treated patients versus 8.8% of surgically treated patients (sHR 0.30; 95% CI 0.29–0.32).

NIVACOR: FOLFOXIRI/bevacizumab plus nivolumab active but toxic in RAS/BRAF-mutated mCRC

NATURE COMMUNICATIONSMar 25, 2026

The phase II NIVACOR trial tested first-line FOLFOXIRI/bevacizumab plus nivolumab in 73 patients with RAS/BRAF-mutated metastatic colorectal cancer. Objective response rate reached 76.7% (95% CI 65.4–85.8%), with disease control in 97.3% (95% CI 90.5–99.7%). Median progression-free survival was 10.1 months (95% CI 9.0–14.3), while median overall survival was not reached. Grade ≥3 treatment-related adverse events occurred in 65.8% of patients, signaling substantial toxicity burden.

Blood ctDNA screening detects many CRCs but misses most advanced precancerous lesions

CRITICAL REVIEWS IN ONCOLOGY/HEMATOLOGYMar 26, 2026

This systematic review and meta-analysis included three prospective population-based ctDNA screening studies with 36,381 average-risk asymptomatic adults. For invasive colorectal cancer, pooled sensitivity was 0.72 (95% CI 0.49–0.88) and specificity 0.91 (95% CI 0.89–0.92). Sensitivity rose from 0.53 in stage I to 0.89 in stage IV, reflecting better performance in advanced disease. For advanced precancerous lesions, sensitivity was only 0.13 (95% CI 0.12–0.14) with specificity 0.90 (95% CI 0.88–0.91).

Global FIT cutoffs dramatically change CRC and advanced lesion detection versus colonoscopy

ECLINICALMEDICINEMar 26, 2026

Investigators applied quantitative FIT positivity thresholds from 30 countries to 7398 German screenees who also underwent colonoscopy. Positivity rates varied from 17.6% at the lowest cutoff (8.5 µg Hb/g) to 2.6% at the highest (120 µg Hb/g). CRC sensitivity ranged from 98.1% to 55.6%, and advanced precancerous lesion sensitivity ranged from 45.5% to 12.2% across thresholds. Sensitivity for any advanced neoplasia varied between 48.9% and 15.0%, while specificity for no advanced neoplasia ranged from 86.3% to 98.9%.

References

Numbered in order of appearance. Click any reference to view details.

Additional Reads

Optional additional studies from this edition.

Edition context

Clinical signal

  • For adhesive SBO, long nonoperative trials are hazardous; timely surgery, especially laparoscopic, minimizes mortality and long-term recurrence.
  • Chemo–immunotherapy can be effective first-line for selected RAS/BRAF-mutated mCRC but demands robust toxicity support and biomarker-aware selection.
  • Noninvasive CRC screening remains cancer-focused; limited advanced precancer detection preserves colonoscopy as the preventive cornerstone.