eP280 - The Pattern of Lymph Node Metastasis and the Outcome of Different Levels of Lymph Node Dissection in Descending Colon Cancer

Sunday, June 2, 2024

11:39 AM – 11:44 AM ET, USA

Location: Baltimore Convention Center, Room 318-320

ePoster Presenter(s)

Yu-Zu Lin, MD (she/her/hers)

Attending physician
Taipei Veterans General Hospital
Taipei, Taipei, Taiwan (Republic of China)

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

Author(s)

CC

Che-Yuan Chang, MD

Attending Physcian
Taipei Veterans General Hospital
Taipei City, Taipei, Taiwan (Republic of China)

Disclosure information not submitted.
YY

Yi-Wen Yang, Colorectal Surgeon

Visiting Staff
Taipei Verteran General Hospital
Taipei, Taipei, Taiwan (Republic of China)

Disclosure information not submitted.
HC

Hou-Hsuan Cheng, n/a

Attending physician
Taipei veterans general hospital
Taipei, Taipei, Taiwan (Republic of China)

Disclosure information not submitted.
SH

Sheng-Chieh Huang, MD

Attending Surgeon
Division of Colon & Rectal Surgery, Department of Surgery, Taipei Veterans General Hospital
Taipei, Taipei, Taiwan (Republic of China)

Disclosure information not submitted.
HL

Hung-Hsin Lin, MD

Attending Physician
Taipei Veterans General Hospital
Taipei, Taipei, Taiwan (Republic of China)

Disclosure information not submitted.
CL

Chun-Chi Lin, MD PhD

Attending Surgeon
Division of Colon & Rectal Surgery, Department of Surgery, Taipei Veterans General Hospital
Taipei, Taipei, Taiwan (Republic of China)

Disclosure information not submitted.
YL

Yuan-Tzu Lan, MD, PhD

attending physician
Taipei Veterans General Hospital
Taipei, Taipei, Taiwan (Republic of China)

Disclosure information not submitted.
HW

Huann-Sheng Wang, MD

Attending Surgeon
Division of Colon & Rectal Surgery, Department of Surgery, Taipei Veterans General Hospital
Taipei, Taipei, Taiwan (Republic of China)

Disclosure information not submitted.
JJ

Jen-Kai Jiang, MD PhD

attending surgeon
taipei veterans general hospital
taipei, Taipei, Taiwan (Republic of China)

Disclosure information not submitted.
SC

Shih-Ching Chang, MD PhD

Attending surgeon
Taipei Veteran general hospital
Taipei, Taipei, Taiwan (Republic of China)

Disclosure information not submitted.

Purpose/Background: Few literatures address the proper extent of lymph node dissection in descending colon cancer, especially when considering the specific location of the tumor. To achieve complete mesocolic excision, the root of the inferior mesenteric artery (IMA) is ligated at the expense of resecting a significant length of the sigmoid colon. Our objective was to investigate the pattern of lymph node metastasis according to different tumor location in the descending colon. We also analyzed the operation quality and the long-term outcome of different levels of dissection along the IMA.Methods/Interventions: Single-center retrospective review of a prospectively maintained colorectal cancer database was performed. All patients with stage I-III descending colon adenocarcinoma between January 2010 and September 2020 were included. The demographics, radiologic studies, operative reports, and post-operative medical records were reviewed. Patients were divided into five groups based on the location of the tumor on pre-operative abdominal computed tomography (CT): proximal third (P), proximal-to-middle third (PM), middle third (M), middle-to-distal third (MD), and distal third (D) of descending colon. The primary endpoint was the frequency of lymph node metastasis at different stations defined in the Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma. The secondary endpoints were intra-operative outcome, specimen quality, and 3-year disease-free survival (DFS) in patients with high and low dissection around the IMA root.Results/Outcomes: A total of 183 patients were identified. Lymph node metastases were observed in 71 cases (38.8%). Seventy-six (41.5%) patients underwent high dissection. The metastasis rates of stations 253, 252, 251, 242, 241, 232, 231 were 4.5, 5.1, 7.7, 8.1, 20.3, 2,4, and 24.4% in the D group, and were 0, 0, 0, 13.3, 9.7, 7.1, 16.6% in the MD group. The metastasis rates of stations of 253, 252, 251, 242, 241, 232, 231, 223, 222, 221 were 12.5, 0, 0, 11.8, 9.5, 0, 8.3, 0, 50, 12.5% in the M group, 0, 0, 0, 0, 0, 5, 15, 0, 11, 0% in the PM group, and 0, 0 ,0 ,0 ,0 ,0, 22.2, 0, 0, 14.3% in the P group. The patients undergoing high dissection had tumor located more distally (P, 3.9%; PM, 2.6%; M, 10.5%; MD, 25%; D, 57.9%, p < 0.01), had advanced clinical T stage (T1 -2, 13.2%; T3-4, 86.8%, p < 0.01) and clinical N stage (N0, 19.7%; N1-2, 80.3%, p < 0.01), and had CT-evident lymph node around the IMA root (high dissection, 25%; low dissection, 11.2%, p = 0.01). Otherwise, there was no significant differences in age, gender, American Society of Anesthesia Classification, Charlson Comorbidity Index, CEA elevation, or tumor size. The lymph node yields were higher (23 vs 17.6 nodes, p < 0.01) and the distal resection margin were longer (11.9 vs 8.8 cm, p < 0.01) in high dissection. The operative time, blood loss, lymph node positivity, and proximal resection margin did not differ between levels of dissection. High dissection was not associated with increased 3-year DFS in overall patients or in different tumor location groups.Conclusion/

Discussion: Lymph node metastasis at the root of IMA were possible when the tumor located at the middle- and distal-third descending colon. However, high dissection did not improve the prognosis. Limitations to our study include its retrospective nature, small sample size, and non-standardized extent of lymph node dissection and minimum resection margin.