QS202 - Disease-Free Survival After Non-Operative Management For Rectal Cancer: A Canadian Institutional Experience

Monday, May 12, 2025

8:16 AM – 8:19 AM PT

Location: Room 9, Upper Level

Quick Shot Presenter(s)

Zarrukh Baig, MD MPH FRCSC

Colorectal Surgery Fellow
St. Paul's Hospital -Vancouver
Vancouver, BC, Canada

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

Author(s)

AG

Amandeep Ghuman, MD FRCSC

Colorectal Surgeon
St. Paul's Hospital-Vancouver
Vancouver, British Columbia, Canada

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This individual has no financial relationships with ineligible companies.
AK

Ahmer A. Karimuddin, MD, FRCSC

Clinical Associate Professor
University of British Columbia
Vancouver, British Columbia, Canada

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This individual has no financial relationships with ineligible companies.
TP

Terry Phang, MD FRCSC

Colorectal Surgeon
St. Paul's Hospital-Vancouver
Vancouver, British Columbia, Canada

Disclosure information not submitted.
EC

Elizabeth A. Clement, MD, MSc, FRCSC

Colorectal Surgeon
University of British Columbia
Vancouver, BC, Canada

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

Manoj Raval, MD FRCSC

Colorectal Surgeon
St. Paul's Hospital-Vancover
Vancouver, British Columbia, Canada

Disclosure information not submitted.
EK

Erin Kennedy, MD FRCSC (she/her/hers)

Colorectal Surgeon
Mount Sinai Hospital - Toronto
Vancouver, British Columbia, Canada

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

Senior Author(s)

Carl Brown, MD FRCSC

Colorectal Surgeon
St. Paul's Hospital - Vancouver
University of British Columbia
Vancouver, British Columbia, Canada

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

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

Zarrukh Baig, MD MPH FRCSC: This individual has no financial relationships with ineligible companies.

Amandeep Ghuman, MD FRCSC: This individual has no financial relationships with ineligible companies.

Ahmer A. Karimuddin, MD, FRCSC: This individual has no financial relationships with ineligible companies.

Elizabeth A. Clement, MD, MSc, FRCSC: This individual has no financial relationships with ineligible companies.

Erin Kennedy, MD FRCSC: This individual has no financial relationships with ineligible companies.

Carl Brown, MD FRCSC: This individual has no relevant relationships with ineligible companies.

Image or Table (Do Not add text here):

Purpose/Background: In Canada, the current standard of care for locally advanced rectal cancer is selective neoadjuvant therapy and radical resection. However, operative management carries significant morbidity, including anastomotic leak, permanent ostomy, sepsis, and low anterior resection syndrome (LARS). Non-operative management (NOM) with close surveillance is a treatment option preferred by many patients who achieve complete clinical response (cCR). Recent publications have demonstrated that NOM patients can be safely managed with close surveillance. Currently, there is limited experience in Canada with NOM for rectal cancer. Our objective is to describe management strategies and outcomes with NOM at a high-volume rectal cancer center in Canada.

Methods/Interventions: A retrospective analysis of prospectively collected data for patients with rectal adenocarcinoma at St. Paul’s Hospital, Vancouver, Canada was conducted. Sixty patients with T2-3N0-1 low rectal cancers treated with neoadjuvant chemoradiation +/- chemotherapy were included in this cohort. Patients with MRI and endoscopic evidence of cCR were invited to participate in a study of NOM after review by a multidisciplinary tumour (MDT) conference and discussion that the standard of care was radical resection. NOM included close surveillance with CT scans every 6 months, MRI, CEA, and flexible endoscopy every three months for 12 months, followed by every six months for 5 years.

Results/Outcomes: Between 2019 and 2024, 60 patients were offered participation in NOM after a complete clinical response. Of these, 55% (33/60) were male. The average age was 62 years old (range 27-86). Two-year follow-up data was available for 47/60 patients. The median follow-up was 31 months +/- 18.60 (range 2-60 months). 30% of patients had T2 disease, and 70% of patients had T3 disease. Nine (15%) patients developed a recurrence in the follow-up period. Local regrowth was seen in 8/60 patients (13.33%); these patients were treated with either low anterior resection (2) or abdominal perineal resection (6). The oncological procedure after re-growth remained the same as discussed at the initial MDT. Four (6.67%) patients developed distal recurrence, and there was one distant recurrence without evidence of local recurrence (1.67%). All occurrences of regrowth or recurrence were identified within 18 months of surveillance initiation.

Conclusion/Discussion: Data from Brazil, Europe and the US suggest NOM is both safe and preferred by many patients despite the risk of regrowth. In Canada, the standard of care remains total mesorectal excision, with some high-volume academic centers offering NOM to select patients. This study is consistent with the literature to date, demonstrating NOM as a viable treatment option with acceptable survival and regrowth rate at two years follow-up. Of the 60 patients, nine experienced regrowth/recurrence, with 8 undergoing successful oncological resection without major changes in the initial operative strategy offered.