P106 - Optimal Timing for Rectal Cancer Surgery after Total Neoadjuvant Therapy: When Does It Get Really Challenging?

Saturday, May 10, 2025

2:30 PM – 2:38 PM PT

Location: Ballroom 6B, Upper Level

Abstract Podium Presenter(s)

Salih Karahan, MD

Research Fellow
Cleveland Clinic Department of Colorectal Surgery
Cleveland Heights, Ohio, United States

All of the relevant financial relationships listed below have been mitigated.
This individual has no financial relationships with ineligible companies.

Author(s)

Kamil Erozkan, MD

Research Fellow
University Hospitals Cleveland Medical Center, Department of Surgery, Division of Colorectal
Cleveland, OH, United States

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Michael A. Valente, DO

Associate Professor of Surgery
Cleveland Clinic
cleveland, Ohio, United States

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This individual has no financial relationships with ineligible companies.
Anuradha R. Bhama, MD

Associate Professor
Cleveland Clinic
Cleveland Clinic
Cleveland, Ohio, United States

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Scott R. Steele, MD, MBA

President, Cleveland Clinic, Main Campus Submarket and Rupert B. Turnbull M.D., Endowed Chair in Colorectal Surgery
Cleveland Clinic
Cleveland, OH, United States

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This individual has no financial relationships with ineligible companies.
Hermann Kessler, MD, PhD, Professor of Surgery (he/him/his)

Staff
Cleveland Clinic Foundation-Main Campus
Cleveland, OH, United States

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David Liska, MD

Associate Professor, Chair
Department of Colorectal Surgery, Cleveland Clinic
Cleveland Clinic, Cleveland, Ohio
Cleveland, Ohio, United States

Disclosure information not submitted.

Senior Author(s)

EG

Emre Gorgun, MD, MBA

Vice Chair, Department of Colorectal Surgery
Cleveland Clinic Foundation-Main Campus
Cleveland, Ohio, United States

All of the relevant financial relationships listed below have been mitigated.
This individual has no relevant relationships with ineligible companies.

Submitting Author(s)

Salih Karahan, MD

Research Fellow
Cleveland Clinic Department of Colorectal Surgery
Cleveland Heights, Ohio, United States

All of the relevant financial relationships listed below have been mitigated.
This individual has no financial relationships with ineligible companies.

All of the relevant financial relationships listed below have been mitigated.

Salih Karahan, MD: This individual has no financial relationships with ineligible companies.

Kamil Erozkan, MD: This individual has no financial relationships with ineligible companies.

Michael A. Valente, DO: This individual has no financial relationships with ineligible companies.

Anuradha R. Bhama, MD: This individual has no financial relationships with ineligible companies.

Scott R. Steele, MD, MBA: This individual has no financial relationships with ineligible companies.

Hermann Kessler, MD, PhD, Professor of Surgery: This individual has no financial relationships with ineligible companies.

Emre Gorgun, MD, MBA: This individual has no relevant relationships with ineligible companies.

Image or Table (Do Not add text here):

Purpose/Background: Total neoadjuvant therapy (TNT) is increasingly preferred for treating locally advanced rectal cancer. However, the optimal timing for surgery after TNT remains uncertain. Current trials report varied intervals: 6-8 weeks (STELLAR, PRODIGE 23), 2-4 weeks (RAPIDO), 6-12 weeks (CAO/ARO/AIO-12), and 11-18 weeks (OPRA). Although surgeons agree that surgery becomes more challenging after a certain point following TNT, the exact timing and its impact on surgical difficulty and complication rates are unclear. This study aims to define the time point when surgery becomes more challenging after TNT and determine the optimal surgical interval based on complication rates and perioperative outcomes.

Methods/Interventions: Patients with locally advanced rectal cancer who underwent TNT followed by surgery between 2018-2024 were included. Patients proceeded to surgery either directly after TNT or following tumor regrowth after a watch-and-wait approach. The interval was defined as the time from TNT completion (end of consolidation chemotherapy or radiotherapy) to surgery. Exclusions included patients with inflammatory bowel disease, hereditary cancer syndromes, or those who underwent IORT, taTME, total proctocolectomy, or synchronous metastasectomy. Restricted cubic spline analysis, a method for modeling non-linear relationships, was used to assess postoperative complications based on the time between TNT and surgery.

Results/Outcomes: Among the 212 patients who underwent surgery following TNT, the median age was 57 years [IQR: 50-66], and the median BMI was 29 [IQR: 24-33]. Most patients were male (59%, n=125). Surgical procedures included low anterior resection in 124 patients (59%) and abdominoperineal resection in 88 patients (41%). The median operative time was 306 minutes [248-396], and estimated blood loss was 100 mL [50-300]. Postoperative complications occurred in 89 patients (42%), with Clavien-Dindo grade ≥3 complications in 31 (15%). Restricted cubic spline analysis revealed a complex association between the time from TNT to surgery and complication odds within 30 days. A protective period between 7-12 weeks was identified, with the lowest odds ratio at 9 weeks (OR=0.6, 95% CI: 0.4–0.9). The odds ratio exceeded 1 at 24 weeks, indicating an increased risk of complications. Comparing those operated < 24 weeks (n=183) vs. ≥24 weeks (n=29), the median TNT-surgery interval was 9 weeks [7-12] vs. 39 weeks [31-69] (p < 0.01). Operative time (305 vs. 317 min, p=0.8) and blood loss (100 mL in both, p=0.2) were similar. Notably, patients in the ≥24 weeks group had a significantly higher rate of circumferential margin positivity (17% vs. 3%, p< 0.01). They also experienced more reoperations (21% vs. 8%, p=0.04) and more severe complications (Clavien-Dindo grade ≥3: 28% vs. 13%, p=0.03).

Conclusion/Discussion: According to our study, the timing of surgery after TNT affects outcomes. A period of 7-12 weeks was associated with fewer complications. After 24 weeks, surgery becomes more challenging, with increased risks of complications, reoperations, and circumferential margin positivity. According to our results, the timing of surgery after TNT plays an important role in determining outcomes, suggesting that careful scheduling may help reduce the risk of complications and challenging surgeries.