eP269 - Total Mesorectal Excision in ypT2 Rectal Cancer After Local Excision Following Neoadjuvant Chemoradiotherapy: Is It Essential?

Sunday, June 2, 2024

10:33 AM – 10:38 AM ET, USA

Location: Baltimore Convention Center, Room 318-320

ePoster Presenter(s)

Tae Gyun Lee, MD

Clinical Assistant Professor
Ajou University Hospital / Seoul National University Bundang Hospital
Seoul National University
Suwon, Kyonggi-do, Republic of Korea

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

Author(s)

AS

Anuj N. Singhi, n/a

Clinical fellow
Seoul National University Bundang Hospital
Seongnam, Kyonggi-do, Republic of Korea

Disclosure information not submitted.
HA

Hong-min Ahn, n/a

Clinical assistant professor
Seoul National University Bundang Hospital
Seongnam, Kyonggi-do, Republic of Korea

Disclosure information not submitted.
HS

Hye Rim Shin, n/a

Clinical fellow
Seoul National University Bundang Hospital
Seongnam, Kyonggi-do, Republic of Korea

Disclosure information not submitted.
Mi Jeong Choi

Clinical fellow
Seoul National University Bundang Hospital
Seongnam, Kyonggi-do, Republic of Korea

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

Clinical fellow
Seoul National University Bundang Hospital
Seongnam, Kyonggi-do, Republic of Korea

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

Heung-Kwon Oh, n/a

Professor
Seoul National University Bundang Hospital
Seongnam, Kyonggi-do, Republic of Korea

Disclosure information not submitted.
DK

Duck-Woo Kim, n/a

Professor
Seoul National University Bundang Hospital
Seongnam, Kyonggi-do, Republic of Korea

Disclosure information not submitted.

Senior Author(s)

SK

Sung-Bum Kang, n/a

Professor
Seoul National University Bundang Hospital
Seongnam, Kyonggi-do, Republic of Korea

Disclosure information not submitted.

Purpose/Background: Non-radical management has replaced total mesorectal excision in good responders after neoadjuvant chemoradiotherapy in mid-to-low rectal cancer patients. This study evaluated the risk factors for lymph node metastasis to find the feasibility of close surveillance in select ypT2 patients after local excision in good responders of neoadjuvant chemoradiotherapy in rectal cancer.Methods/Interventions: We included ypT2 rectal cancer patients who received neoadjuvant chemoradiotherapy followed by total mesorectal excision between January 2004 and December 2022. Clinicopathologic parameters were evaluated to identify risk factors for lymph node metastasis.Results/Outcomes: Of 198 patients, 158 (79.8%) had ypT2N0 and 40 (20.2%) had ypT2N+. In the univariable analyses, the risk factors of lymph node metastasis were perineural invasion (48.0% vs. 16.3% without perineural invasion, P < 0.001), female gender (30.0% vs. 14.8% with male, P = 0.011), and clinically node positive after neoadjuvant chemoradiotherapy (32.6% vs. 16.4% with node negative, P = 0.017). These factors were also confirmed as independent risk factors on multivariable analysis (perineural invasion [OR = 4.50, 95% CI; 1.79 – 11.29, P < 0.001], female gender [OR = 2.62, 95% CI; 1.24 – 5.52, P = 0.012] and clinical node involvement after neoadjuvant chemoradiotherapy [OR = 2.28, 95% CI; 1.03 – 5.05, P = 0.012]). The rate of lymph node metastasis in ypT2 patients without all three risk factors was 12.5%.Conclusion/

Discussion: This study demonstrated high probability of lymph node metastasis in ypT2 even without risk factors such as perineural invasion, female gender and clinical node involvement after neoadjuvant chemoradiotherapy. We confirm that total mesorectal excision should be standard in ypT2 after local excision.