Oncological outcomes of direct versus delayed surgery after neoadjuvant short-course radiotherapy for rectal cancer: national cohort study

Why clinicians should know about it

• Picked for Radiology, Radiation Oncology, Nuclear Medicine, Medical Physics and Imaging (paper of the day, 16 October 2026): Direct vs delayed surgery after short‑course RT

Abstract

BACKGROUND: After the Stockholm III trial, a trend towards delayed surgery after neoadjuvant short-course radiotherapy (5 × 5 Gy) for rectal cancer has emerged in Sweden, driven by the lower short-term complication rates and similar oncological outcomes. This study aimed to examine long-term oncological outcomes after neoadjuvant short-course radiotherapy, comparing direct versus delayed surgery for rectal cancer in a real-world setting. METHODS: A registry-based retrospective national cohort study was conducted using prospectively collected data from the Swedish Colorectal Cancer Registry. Patients with rectal cancer receiving neoadjuvant neoadjuvant short-course radiotherapy with surgery between 2016 and 2020 were analysed for oncological outcomes (local recurrence, distant metastasis) and overall survival at 3 years, comparing direct surgery, defined as surgery within 7 days after neoadjuvant short-course radiotherapy, and delayed surgery, defined as surgery after 28-90 days. The rate of patients who underwent surgery within the delayed time frame of the Stockholm III trial was also recorded. RESULTS: A total of 2080 patients were identified, of whom 1208 (58.1%) underwent direct surgery and 872 had delayed surgery. Of note, only 288 patients underwent resection 28-56 days after neoadjuvant short-course radiotherapy (within the time frame of the Stockholm III trial). Although the pathological complete response rate was higher in the delayed-surgery group compared with the direct-surgery group (6.5% versus 0.4%), 3-year local recurrence and distant metastasis rates were, respectively, 1.0% (12 patients) and 6.8% (82) in the direct-surgery group, and 3.4% (30) and 11.9% (104) in the delayed-surgery group. The adjusted hazard ratios for local recurrence and distant metastasis comparing delayed surgery with direct surgery were 3.60 (95 per cent confidence interval 1.75 to 7.39) and 2.17 (1.58 to 2.96), respectively, whereas the adjusted hazard ratio for overall survival was 1.37 (1.06 to 1.77), favouring the direct-surgery group. CONCLUSION: In a real-world setting, the results indicate that few patients in the delayed-surgery group had surgery within the stipulated time frame. Considering this, delayed surgery was associated with a higher risk of local recurrence, distant metastasis, and reduced overall survival.

Abstract as published, via PubMed.