EP747 - Safety and Oncologic Efficacy of Minimally Invasive Resection for Terminal Ileum Neuroendocrine Tumors

ePoster Presenter(s)

• 

  Despoina Kanata, MD (she/her/hers)

  Research fellow
  Memorial Sloan Kettetring Cancer Center
  Memorial Sloan Kettering Cancer Center
  New York, NY, United States

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

Author(s)

• 

  Francesca Roufael, MD

  Research fellow
  Department of colorectal surgery - Memorial Sloan Kettering Cancer Center
  Memorial Sloan Kettering Cancer Center
  New York, NY, United States

  Disclosure information not submitted.
• TG

  Tina Gowda, MD

  Research fellow
  Colorectal Surgery, Memorial Sloan kettering
  New York, New York, United States

  Disclosure information not submitted.
• MA

  Mohammad Ali Abbass, MD MPH

  Assistant Attending
  Memorial Sloan Kettering Cancer Center
  New York, New York, United States

  Disclosure information not submitted.
• 

  Georgios Karagkounis, MD

  Assistant Attending
  Memorial Sloan Kettering Cancer Center
  Memorial Sloan Kettering
  New York, NY, United States

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

  Maria Widmar, MD, MPH (she/her/hers)

  Assistant Attending
  Memorial Sloan Kettering Cancer Center
  Weill Cornell Medical Center
  New York, New York, United States

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

  Iris H. Wei, MD

  Assistant Attending
  Memorial Sloan Kettering Cancer Center
  New York, New York, United States

  Disclosure information not submitted.
• 

  J. Joshua Smith, MD, PhD

  Professor and Chair, Colon and Rectal Surgery Department
  MD Anderson Cancer Center
  MD Anderson Cancer Center
  Houston, TX, United States

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

  Garrett M. M. Nash, MD, MPH

  Vice Chair of Quality and Safety
  Memorial Sloan Kettering Cancer Center
  New York, New York, United States

  Disclosure information not submitted.
• 

  Martin R. Weiser, MD

  Vice Chair for Faculty Affairs
  Memorial Sloan Kettering Cancer Center
  Cornell Medical College
  New York, New York, United States

  Disclosure information not submitted.
• 

  Philip B. B. Paty, MD

  Attending Surgeon
  Memorial Sloan Kettering Cancer Center
  New York, New York, United States

  Disclosure information not submitted.
• 

  Andrea Cercek, MD

  Associate Physician
  Memorial Sloan Kettering Cancer Center
  New York, New York, United States

  Disclosure information not submitted.
• LS

  Leonard Saltz, MD

  Attending Physician
  Department of Medical Oncology, Memorial Sloan Kettering Cancer Center
  New York, New York, United States

  Disclosure information not submitted.
• 

  Julio Garcia Aguilar

  Disclosure information not submitted.

Senior Author(s)

• 

  Emmanouil Pappou, MD, PhD

  Assistant Attending
  Memorial Sloan Kettering Cancer Center
  New York, New York, United States

  Disclosure information not submitted.

Purpose/Background: Terminal ileal neuroendocrine tumors (I-NETs) are one of the most common small bowel malignancies and often present with nodal involvement, mesenteric fibrosis, or synchronous primaries. Oncologic resection with lymphadenectomy is the standard of care, but the optimal surgical approach (open vs. minimally invasive) remains debated due to concerns about completeness of resection, lymph node yield, and long-term outcomes. Emerging reports suggest feasibility and safety of minimally invasive colectomy for I-NETs. We aimed to compare perioperative and oncologic outcomes between minimally invasive and open resection in a large single-institution cohort.

Methods/Interventions: We retrospectively identified consecutive patients with stage I-III terminal ileum neuroendocrine tumors who underwent curative-intent resection at a tertiary cancer center from January 2000 to December 2023. Exclusion criteria included follow-up < 6 months, recurrent tumors with primary excised at another institution, palliative resections, incidental findings without definitive treatment, and endoscopic resections with no residual carcinoid in the surgical specimen. We compared patient demographics, operative details, pathology findings, and oncologic outcomes between open and minimally invasive approaches. Kaplan-Meier analysis estimated overall survival (OS) and disease-free survival (DFS), as well as Cox regression evaluated associations between surgical approach and outcomes.

Results/Outcomes: Among 101 patients, 77 (76%) underwent minimally invasive and 24 (24%) open resection. Baseline demographics, tumor size (median 1.4 cm), nodal positivity (90%), and stage distribution were similar between groups. Minimally invasive surgery had a longer operative time (151 vs 106 min, p< 0.001) , lower length of small bowel resection (11 vs 18 cm, p=0.069) and similar blood loss. R0 resection was achieved in 97% of patients in both groups, with no difference in lymph node yield (median 23 vs 20, p=0.3). Postoperative complications and readmission rates were low and similar between approaches. At median follow-up of over 5 years, 10 patients (9.9%) developed recurrence. Five-year OS was 96% vs. 95% and 5-year DFS was 83% vs. 91% for minimally invasive versus open surgery, with no significant differences between approaches (p=0.51 and p=0.77, respectively). On Cox regression analysis, operative approach (minimally invasive vs. open) was not associated with overall survival (HR 0.62, 95% CI 0.15-2.62) or disease-free survival (HR 1.18, 95% CI 0.39-3.51). The only variable significantly associated with recurrence was lymphovascular invasion (HR 9.57, 95% CI 1.12-81.5, p=0.024).

Conclusion/Discussion: In this large single-institution series, minimally invasive resection of terminal ileum neuroendocrine tumors was associated with similar short- and long-term oncologic outcomes as open surgery, with comparable R0 resection rates, lymph node harvest, and survival. Operative approach did not impact recurrence or survival outcomes, whereas lymphovascular invasion was the only independent predictor of recurrence. Given its advantages in recovery and similar oncologic efficacy, minimally invasive surgery should be considered the preferred approach for appropriately selected patients.

Disease Free Survival of patients with Open vs Minimally Invasive resected tumors
Disease Free Survival of patients with Open vs Minimally Invasive resected tumors