EP749 - Beyond local response: assessing systemic impacts in pathologic complete response in locally advanced rectal cancer: comparative study

Monday, May 12, 2025

10:20 AM – 10:25 AM PT

ePoster Presenter(s)

Seungho Song

Assistant professor
Kyungpook National University Chilgok Hospital
Daegu, Taegu-jikhalsi, Republic of Korea

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

Senior Author(s)

GC

Gyu-Seog Choi, n/a

professor
Kyungpook National University Chilgok Hospital
daegu, Taegu-jikhalsi, 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)

JP

Jun Seok Park, n/a

professor
Kyungpook National University Chilgok Hospital
Dae Ku, Taegu-jikhalsi, Republic of Korea

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

Soo Yeun Park, n/a

professor
Kyungpook National University Hospital
daegu, Taegu-jikhalsi, Republic of Korea

Disclosure information not submitted.
HK

Hye Jin Kim, n/a

professor
Kyungpook National University Hospital
Daegu, Taegu-jikhalsi, Republic of Korea

Disclosure information not submitted.
Sung-Min Lee, n/a

clinical professor
Kyungpook National University Hospital
Kyungpook National University
daegu, Taegu-jikhalsi, Republic of Korea

Disclosure information not submitted.
MJ

Min Hye Jeong, n/a

Fellow
Kyungpook National University Chilgok Hospital
daegu, Taegu-jikhalsi, Republic of Korea

Disclosure information not submitted.
SK

Soo Jin Kang, n/a

Fellow
Kyungpook National University Hospital
Daegu, Taegu-jikhalsi, Republic of Korea

Disclosure information not submitted.

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

Seungho Song: This individual has no financial relationships with ineligible companies.

Gyu-Seog Choi, n/a: This individual has no financial relationships with ineligible companies.

Jun Seok Park, n/a: This individual has no financial relationships with ineligible companies.

Image or Table (Do Not add text here):

Purpose/Background: The role of radiation therapy in managing locally advanced rectal cancers has evolved over the years. This study aimed to investigate the long-term oncological impact of patients achieving a pathological complete response (pCR) following preoperative chemoradiotherapy (CRT) compared to those who did not achieve pCR and did not receive preoperative CRT in locally advanced rectal cancer.

Methods/Interventions: This retrospective comparative study included three patient cohorts: Group A (no preoperative CRT), Group B (preoperative CRT without pCR), and Group C (preoperative CRT with pCR). Data from two distinct periods were analyzed, one before and one after the routine implementation of preoperative CRT. Various clinical and oncological parameters were evaluated.

Results/Outcomes: The study included 1,105 patients, distributed across three groups: Group A included 608 patients, Group B consisted of 407 patients, and Group C comprised 90 patients. Group C demonstrated significantly better 5-year overall survival (96.1%) compared to Group B (81.7%) and Group A (77.6%). Local recurrence rates were significantly lower in Group C (98.8%) compared to Group A (90.1%). Group B showed comparable survival rates to Group A but with significantly reduced local recurrence.

Conclusion/Discussion: Patients who achieving pCR following preoperative CRT for locally advanced rectal cancer demonstrated improved long-term survival and lower rates of local recurrence. In contrast, patients who did not achieve pCR following preoperative CRT showed similar survival rates to those who did not receive preoperative CRT, albeit with better local control.