EP674 - Oncologic outcomes of chemoradiotherapy without total mesorectal excision at early rectal cancer patients

Sunday, May 10, 2026

4:17 PM - 4:22 PM ET

ePoster Presenter(s)

Junyong Han, Doctor, Resident (he/him/his)

Resident
Seoul national university division of general surgery
Seoul national university hospital, Department of surgery
Seoul, Seoul-t'ukpyolsi, Republic of Korea

Disclosure information not submitted.

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Senior Author(s)

Seung-Bum Ryoo, MD, PhD (he/him/his)

Professor
Colorectal Surgery division, Surgery department, Seoul national university hospital
Seoul National University, College of Medicine
Seoul, Seoul-t'ukpyolsi, Republic of Korea

All disclosed relationships have been reviewed and managed prior to the start of this activity. Any relevant relationships will be listed below. This individual has no financial relationships to disclose

Author(s)

Ji Won Park, MD, PhD (he/him/his)

Clinical Professor
Seoul National University Hospital
Seoul National University College of Medicine
Seoul, Seoul-t'ukpyolsi, Republic of Korea

All disclosed relationships have been reviewed and managed prior to the start of this activity. Any relevant relationships will be listed below. This individual has no financial relationships to disclose
JP

Jesung Park, MD., Ph.D

Fellow
Seoul National University Hospital
Seoul, Seoul-t'ukpyolsi, Republic of Korea

Disclosure information not submitted.
JP

Jae Hyun Park, MD

Clinical Fellow
Seoul National University Hospital
Seoul, Seoul-t'ukpyolsi, Republic of Korea

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Purpose/Background: Doing TME in patients unable to perform for reasons such as patient rejection and high op risk can have miserable consequences such as anastomotic leakage, fecal incontinence and permanent stoma. For these situations, many rectum preserving alternatives have been proposed. One of the representative alternatives is local excision, but patients who don't fit to local excision indications have no other option than TME.

This study aims to suggest chemoradiotherapy (CRT) as an alternative choice in early rectal cancer patient (clinical stage T1/2 N0) who reject or cannot receive TME. By comparing the oncologic outcomes between CRT without TME and non-RT with TME, we investigate an efficacy of CRT as an alternative to successfully remove early rectal cancer while preventing recurrence at early rectal cancer

Methods/Interventions: Doing TME in patients unable to perform for reasons such as patient rejection and high op risk can have miserable consequences such as anastomotic leakage, fecal incontinence and permanent stoma. For these situations, many rectum preserving alternatives have been proposed. One of the representative alternatives is local excision, but patients who don't fit to local excision indications have no other option than TME.

This study aims to suggest chemoradiotherapy (CRT) as an alternative choice in early rectal cancer patient (clinical stage T1/2 N0) who reject or cannot receive TME. By comparing the oncologic outcomes between CRT without TME and non-RT with TME, we investigate an efficacy of CRT as an alternative to successfully remove early rectal cancer while preventing recurrence at early rectal cancer

Results/Outcomes: Among the 133 patients, 33 patients underwent CRT without TME, 100 received TME without RT. Median follow up duration was 19 months at CRT without TME group and 90 months at non-RT with TME group (p=0.001). There was no significant difference in clinical T stage (p=0.300) and tumor size (19.39mm vs 19.50mm, CRT without TME vs non-RT with TME, p=0.967). An average ASA score was higher at CRT without TME group (p=0.009). At CRT without TME group, 29 of 33 patients have received CRT in combination with local excision (87.9%). While there was no major complication at CRT without TME group, 10 complications including anastomosis leakage and bowel ischemia have occurred at non-RT with TME group (10 of 100, 10%). 17 of 100 patients have done stoma formation during surgery at non-RT with TME group (17%). Ratio of no residual tumor (ypT0) at CRT without TME group was 48.3% (14 of 29). 19 patients of CRT without TME group had 1 or 2 grade of TRG at rectal MRI after RT (19 of 22, 86.3%). There was no difference in the recurrence rate (2 of 33, 6.1% in CRT without TME vs. 6 of 100, 6% in non-RT with TME, p=0.990). Also, there was no statistically significant difference in time to recurrence, overall survival and recurrence-free survival between the two groups (TTR; p=0.233, OS; p=0.066, RFS; p=0.071).

Conclusion/Discussion: Oncologic outcomes of CRT without TME in early rectal cancer is not inferior to radical resection and should be considered as a choice of treatment if patients reject or cannot receive TME.

Survival rate comparison between non-RT with TME vs CRT without TME

There was no statistically significant difference in time to recurrence, overall survival and recurrence-free survival between the two groups (TTR; p=0.233, OS; p=0.066, RFS; p=0.071).
Oncologic outcomes between non-RT with TME vs CRT without TME

Ratio of no residual tumor (ypT0) at CRT without TME group was 48.3% (14 of 29). 19 patients of CRT without TME group had 1 or 2 grade of TRG at rectal MRI after RT (19 of 22, 86.3%). There was no difference in the recurrence rate (2 of 33, 6.1% in CRT without TME vs. 6 of 100, 6% in non-RT with TME, p=0.990).