93: Effectiveness of Sentinel Lymph Node Mapping in Gastric Cancer

Friday, March 24, 2023

11:01 AM – 11:11 AM

Location: Ballroom A

Abstract Presenter(s)

Miseker E. Abate, MD, MPH

Research Fellow
Memorial Sloan Kettering Cancer Center, United States

Disclosure(s): No financial relationships to disclose

First Author(s)

Miseker E. Abate, MD, MPH

Research Fellow
Memorial Sloan Kettering Cancer Center, United States

Disclosure(s): No financial relationships to disclose

Author(s)

Harrison M. Drebin, BA

Research Coordinator
Memorial Sloan Kettering Cancer Center, United States

Disclosure information not submitted.
TF

Teng Fei, PhD

Biostatistician
Memorial Sloan Kettering Cancer Center, United States

Disclosure information not submitted.
KP

Katherine Poruk, MD

Surgical Oncology
The Mayo Clinic - Jacksonville, United States

Disclosure information not submitted.
MN

Madalyn Neuwirth, MD

Surgical Attending
Memorial Sloan Kettering Cancer Center, United States

Disclosure information not submitted.
BF

Benjamin Ferguson, MD, PhD

Surgical Attending
Memorial Sloan Kettering Cancer Center, United States

Disclosure information not submitted.
Shoji Shimada, MD, PhD (he/him/his)

Research Fellow
Memorial Sloan Kettering Cancer Center
New York, New York, United States

Disclosure information not submitted.
LT

Laura Tang, MD, PhD

Pathologist
Memorial Sloan Kettering Cancer Center, United States

Disclosure information not submitted.
SV

Santosh Vardhana, MD, PhD

Assistant Attending
Memorial Sloan Kettering Cancer Center, United States

Disclosure information not submitted.
Vivian E. Strong, MD

Iris Cantor Endowed Chair and Attending Surgeon, MSKCC and Professor of Surgery and Associate Dean, Weill Medical College of Cornell University
Memorial Sloan Kettering Cancer Center
New York, New York, United States

Disclosure(s): Merck: Speaker (Terminated, November 1, 2022)

Disclosure(s):

Miseker E. Abate, MD, MPH: No financial relationships to disclose

Vivian E. Strong, MD: Merck: Speaker (Terminated, November 1, 2022)

Introduction: Lymph node (LN) metastasis is a critical prognostic factor for patients with gastric carcinoma (GC). Sentinel LN biopsy (SLNB) has the potential to identify the initial site of draining LN metastasis and reduce the extent of surgical lymphadenectomy. However, its utility in the U.S. GC population is unknown. In this study, we evaluate the specificity of SLNB and identify factors associated with SLNB’s capacity to determine regional LN metastasis.

Methods: This prospective study included 106 patients with GC who had total or partial gastrectomy with D2 lymphadenectomy, and indocyanine green fluorescence guided sentinel LN (SLN) mapping. Factors associated with successful identification of SLN were assessed. SLN status obtained on pathology report was compared to the LN status of the D2 lymphadenectomy. The negative predictive value (NPV) of SLNB was calculated (True Negative/(True Negative + False Negative)) and compared across patient subgroups using hypothesis testing of association.

Results: 91 patients (86%) had successful SLN identification following SLN mapping. There were no statistically significant patient, tumor, or treatment factors associated with successful identification of SLN (p >0.05). For the entire cohort with negative SLNB (n=63) on final pathology, the NPV was 81%. Patients with negative SLNB and pathologic tumor stage (T) < 3 had a significantly higher NPV when compared to those with T > 3 (91% vs 60%, p=0.012) (Figure1A). Patients with negative SLNB and no lymphovascular invasion (LVI) had a significantly higher NPV when compared to those with LVI (97% vs 54%, p< 0.001) (Figure1B). There were no statistically significant differences in the NPV of SLNB between patients with and without neoadjuvant chemotherapy, and patients with diffuse and intestinal GC (p >0.05).

Conclusions: Our results show that for patients with early-stage GC and patients with no LVI who have negative SLNB, regional LN metastasis can be reliably predicted. This suggests that SLNB can successfully predict negative regional LN metastasis and is a promising approach to reduce the extent of surgical lymphadenectomy in selected cases of GC.

Learning Objectives:

Describe a gastric cancer patient population that may benefit from sentinel lymph node biopsy and a subsequent reduction in the extent of lymphadenectomy
List factors associated with successful identification of Sentinel lymph nodes in gastric cancer
Describe the association of negative lymphovascular invasion and negative sentinel lymph node biopsy in reliably predicting negative regional lymph node metastasis