EP182 - Neoadjuvant Chemotherapy Associated with Lower Lymph Node Yield but Improved Survival in Patients with Colon Cancer Undergoing Colectomy: NCDB Analysis

ePoster Presenter(s)

• 

  Katie Carsky, MD, MS (she/her/hers)

  Fellow
  Cleveland Clinic Florida
  Pembroke Pines, FL, United States

  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

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Author(s)

• 

  Sameh H. Emile, MBBCh, MSc, MD, FACS

  Project Scientist
  Cleveland Clinic Florida
  Cleveland Clinic Florida
  Weston, FL, United States

  Disclosure information not submitted.
• 

  Nir Horesh, MD

  Resident Physician
  Cleveland Clinic Florida
  Tel Aviv University
  Weston, FL, United States

  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
• GD

  Giovanna Dasilva, MD

  Staff Colorectal Surgeon
  Cleveland Clinic Florida
  Cleveland Clinic Florida
  Weston, Florida, United States

  Disclosure information not submitted.
• 

  Marylise Boutros, MD, FRCSC, FACS, FACRS (she/her/hers)

  Colorectal Surgeon
  Cleveland Clinic Florida
  McGill University
  Weston, Florida, United States

  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 relevant financial relationships.
• 

  Dana Sands, MD

  Staff Surgeon

  Disclosure information not submitted.

Senior Author(s)

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  Steven D. Wexner, MD, PhD (Hon)

  Surgeon
  Cleveland Clinic Florida
  Cleveland Clinic Lerner College of Medicine at Case Western Reserve University
  Weston, Florida, United States

  Disclosure information not submitted.

Purpose/Background: Lymph node (LN) yield is a key quality metric in colon cancer surgery. The National Comprehensive Cancer Network (NCCN) Guidelines use a cutoff of ≥12 LN as the minimum standard for oncologic resection. Rectal cancer literature suggests that decreased LN yield after neoadjuvant therapy may be clinically insignificant. This study investigates whether patients receiving neoadjuvant chemotherapy before colectomy for adenocarcinoma have lower LN yield than those undergoing upfront surgery. A secondary objective was to assess if suboptimal LN yield is associated with worse 5-year overall survival (OS) in stage III disease.

Methods/Interventions: A retrospective analysis of the National Cancer Database (NCDB) was performed, including patients from 2012-2022 who underwent colectomy for stage I-III colon adenocarcinoma. Suboptimal LN yield was defined as < 12. Multivariable logistic regression was performed to examine the association between neoadjuvant chemotherapy and suboptimal LN yield. Multiple linear regression (MLR) estimated the mean difference in node count between patients who received or did not receive neoadjuvant chemotherapy. Five-year OS in stage III was stratified by neoadjuvant chemotherapy and LN yield.

Results/Outcomes: Overall, 2,306 (2.1%) of 106,792 patients received neoadjuvant chemotherapy. Neoadjuvant chemotherapy was associated with higher odds of a suboptimal LN yield (OR 2.94, CI 2.37-3.64). On MLR, neoadjuvant chemotherapy was associated with a decrease of 2.63 nodes (CI -3.35 to -1.92). The median LN yield in the suboptimal and optimal groups was 8 (95% CI 5-10) LNs vs 19 (95% CI 15-26, p< 0.001), respectively. The 5-yr OS in stage III disease was higher when neoadjuvant chemotherapy was given, whether the LN yield was optimal (70.5%; 95%CI 66.8-73.8 vs. 61.6%; 95%CI 60.9-62.4) or suboptimal (63.0%; 95%CI 51.2-72.6 vs. 46.3%; 95% CI 43.1-49.4).

Conclusion/Discussion: Neoadjuvant chemotherapy was independently associated with substandard minimum LN yield. However, among patients with stage III disease, a suboptimal LN yield after neoadjuvant chemotherapy was not associated with reduced 5-yr OS. These findings mirror neoadjuvant radiation for rectal cancer data and suggest that reduced LN yield following neoadjuvant therapy is not associated with the same adverse prognostic implication as an unexpectedly low LN count after upfront resection. In these patients, a yield < 12 may be acceptable. However, small sample size in the neoadjuvant chemotherapy/-suboptimal and limitations of retrospective registry data warrant cautious interpretation and prospective validation. Although neoadjuvant therapy is associated with reduced LN yield, that reduction does not have an adverse impact on survival.

Figure.
Probability of recurrence in patients with and without optimal lymph node yield