P80: Accuracy of Clinical Staging for Intramural (T2) Gastric Cancer: Survival Outcomes Following Upfront Surgical Resection Compared to Risk of Overtreatment with Neoadjuvant Therapy

Thursday, March 23, 2023

9:46 AM – 9:51 AM

Location: SSO HUB Pan-Tumor Zone: CRS, HPB, Pan-Tumor & Upper GI

Poster Presenter(s)

Nazanin Khajoueinejad, MD (she/her/hers)

Research Resident
Icahn School of Medicine at Mount Sinai
New York, New York, United States

Disclosure information not submitted.

Author(s)

Nazanin Khajoueinejad, MD (she/her/hers)

Research Resident
Icahn School of Medicine at Mount Sinai
New York, New York, United States

Disclosure information not submitted.
SI

Sayed Imtiaz, MD

Resident
Downstate School of Medicine, United States

Disclosure information not submitted.
YB

Yael Berger, MD

Resident Physician
Rabin Medical Center, United States

Disclosure information not submitted.
DM

Deepti Mahajan, n/a

Student
Downstate School of Medicine, United States

Disclosure information not submitted.
DD

Demetrius Durham, MD

Resident
Garnet Health Medical Center, United States

Disclosure information not submitted.
NC

Noah Cohen, MD

Assistant Professor of Surgery
Icahn School of Medicine at Mount Sinai, United States

Disclosure information not submitted.
DL

Daniel Labow, MD

Professor of Surgery, Executive Vice Chair of Surgery
Icahn School of Medicine at Mount Sinai, United States

Disclosure information not submitted.
US

Umut Sarpel, MD, MS

Professor of Surgery
Icahn School of Medicine at Mount Sinai, United States

Disclosure information not submitted.
BG

Benjamin Golas, MD

Chief, Division of Surgical Oncology
Mount Sinai Health System
New York, New York, United States

Disclosure information not submitted.
HT

Hideo Takahashi, MD

Assistant Professor of Surgery
Icahn School of Medicine at Mount Sinai, United States

Disclosure information not submitted.
SH

Spiros Hiotis, MD, PhD

Associate Professor of Surgery
Icahn School of Medicine at Mount Sinai
New York, New York, United States

Disclosure information not submitted.

Introduction: Based on current recommendations, patients with early gastric cancers (T1) are treated with upfront resection while those with locoregional disease often are recommended for multimodal therapy. Over-staging by endoscopic ultrasound (EUS), specifically in those with intramural (T2) disease, introduces the risk of overtreatment with neoadjuvant chemotherapy without the benefit of a confirmed pathological stage. This risk of overtreatment compared to the risk of recurrence after upfront surgery must be weighed in this group, especially when nodal involvement is not histologically confirmed with clinical staging.

Methods: We retrospectively reviewed all patients with gastric cancer who underwent upfront surgical resection between 2010 and 2020 at a single North American academic medical center. Patients were only included if they did not receive preoperative systemic therapy or radiation. EUS clinical staging and pathological staging were reconciled for accuracy. Recurrence free survival and overall survival was calculated for the intramural (T2) group. Survival was confirmed by review of the Social Security Death Index.

Results: One hundred thirty-four patients met inclusion criteria. EUS staging was correct in staging T2 disease for 8/37 (22%) of patients compared to 35/57 (61%) of patients with T1 disease. EUS over-staged 20/37 (54%) of patients defined as having clinical T2 compared to 11/57 (19%) of clinical T1 disease (Table). Lymph node involvement (cN+) as determined by EUS without biopsy was accurate in 9/34 (26%) when compared to final pathology. In total, 22 cases were confirmed as intramural disease (T2) on final pathology. Four patients with T2 disease (18%) experienced recurrence (median time to recurrence 42 months, range 14-60). Three of those that recurred were offered adjuvant chemotherapy, but declined. The 5 year overall survival for this group was 100%, with median follow-up of 32 months.

Conclusions: Patients with intramural (T2) gastric cancer who underwent upfront surgical resection without neoadjuvant systemic therapy or radiation demonstrated excellent recurrence free and overall survival. We propose reconsideration of T2 gastric cancers as intramural disease and removal of these patients from neoadjuvant algorithms as they are at risk of inaccurate clinical staging by EUS and may be over-treated without a survival benefit.

Learning Objectives:

Upon completion, participants will be able to compare the accuracy of EUS vs pathological staging for gastric cancer.
Upon completion, participants will be able to describe the staging accuracy of EUS vs pathological staging for nodal involvement.
Upon completion, participants will be able to report the overall survival for patients who underwent upfront surgical resection with T2 gastric cancer.