Gastrointestinal Cancer

PV QA 1 - Poster Viewing Q&A 1

SU_1_2005 - Importance of Tumor Regression Grade in ypStage III Rectal Cancer Patients Treated with Neoadjuvant Chemoradiotherapy

Sunday, October 21
1:15 PM - 2:45 PM
Location: Innovation Hub, Exhibit Hall 3

Importance of Tumor Regression Grade in ypStage III Rectal Cancer Patients Treated with Neoadjuvant Chemoradiotherapy
J. H. Chung1, C. Song1, S. B. Kang2, D. W. Kim2, J. H. Kim3, K. W. Lee3, and J. S. Kim1; 1Department of Radiation Oncology, Seoul National University Bundang Hospital, Seongnamsi, Korea, Republic of (South), 2Department of Surgery, Seoul National University Bundang Hospital, Seongnamsi, Korea, Republic of (South), 3Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnamsi, Korea, Republic of (South)

Purpose/Objective(s): Complete and partial tumor regressions are associated with improved long-term outcome in patients with rectal cancer after neoadjuvant chemoradiotherapy (NCRT). ypStage III rectal cancer consists of lymph node positive patients with heterogeneous prognosis. Introducing tumor regression grade (TRG) into heterogeneous ypStage III rectal cancer may provide clue on selecting out patients who might acquire maximal benefit from intensified adjuvant treatment. This study was performed to evaluate the prognostic impact of the tumor regression grade in ypStage III rectal cancer patients treated with NCRT.

Materials/Methods: In this retrospective study, 287 patients with locally advanced rectal cancer received NCRT at our institution from 2003 to 2015. ypStage III patients were classified into two subgroups based on the combination of ypStage and TRG: ypStage III patients with good TRG (TRG 3-4) and ypStage III patients with poor TRG (TRG 1-2).

Results: Median follow-up time was 51.3 months. 5-year overall survival (OS) and 5-year distant metastasis-free survival (DMFS) were 86.0% and 78.5%, respectively. When ypStage III patients were divided into ypStage III & TRG 3-4 subgroup and ypStage III & TRG 1-2 subgroup, ypStage III & TRG 1-2 patients had worse 5-year OS (95.8% vs. 62.0%, p = 0.023) and 5-year DMFS (78.8% vs. 56.1%, p = 0.073) compared to the ypStage III & TRG 3-4 patients. And there were no differences between the ypStage II subgroup and the ypStage III & TRG 3-4 subgroup in terms of the 5-year OS (86.9% vs. 95.8%, p=0.405) and 5-year DMFS (79.3% vs. 78.8%, p=0.683). Multivariate analyses showed that grouping patients into 3 modified subgroups – ypStage 0-I, ypStage II/ypStage III & TRG 3-4, and ypStage III & TRG 1-2 – clearly divides patients and this grouping itself becomes the most important prognostic factor for predicting OS (p<0.001) and DMFS (p<0.001).

Conclusion: Degree of tumor regression after NCRT significantly divided heterogeneous ypStage III rectal cancer patients into two groups: ypStage III patients with good TRG (TRG 3-4) and ypStage III patients with poor TRG (TRG 1-2). Therefore, TRG may be used to discern a high-risk group in ypStage III patients who might benefit from more intensified adjuvant treatment.

Author Disclosure: J. Chung: None. C. Song: None. D. Kim: None.

Send Email for Changhoon Song


Assets

SU_1_2005 - Importance of Tumor Regression Grade in ypStage III Rectal Cancer Patients Treated with Neoadjuvant Chemoradiotherapy



Attendees who have favorited this

Please enter your access key

The asset you are trying to access is locked. Please enter your access key to unlock.

Send Email for Importance of Tumor Regression Grade in ypStage III Rectal Cancer Patients Treated with Neoadjuvant Chemoradiotherapy