92: Phase I Trial of Short-Course Chemoradiotherapy followed by Chemotherapy as Total Neoadjuvant Therapy for Patients with Potentially Resectable Gastric Cancer

Friday, March 22, 2024

11:02am – 11:12am ET

Location: C102

Abstract Presenter(s)

Brian Badgwell, MD, MS

Professor of Surgery
MD Anderson Cancer Center
Houston, Texas, United States

Submitter(s)

Brian Badgwell, MD, MS

Professor of Surgery
MD Anderson Cancer Center
Houston, Texas, United States

Author(s)

Brian Badgwell, MD, MS

Professor of Surgery
MD Anderson Cancer Center
Houston, Texas, United States
PD

Prajnan Das, MD

Chair Ad Interim
MD Anderson Cancer Center, United States
Naruhiko Ikoma, MD, MS

Assistant Professor of Surgical Oncology
The University of Texas MD Anderson Cancer Center
Houston, Texas, United States
MB

Mariela Blum, MD

Associate Professor
MD Anderson Cancer Center, United States
JL

Jenny Li, MD

Assistant Professor
MD Anderson Cancer Center, United States
JE

Jeannelyn Estrella, MD

Professor
MD Anderson Cancer Center, United States
BM

Bruce Minsky, MD

Professor
MD Anderson Cancer Center, United States
PM

Paul F. Mansfield, MD

Professor
MD Anderson Cancer Center, United States
JA

Jaffer Ajani, MD

Professor
MD Anderson Cancer Center, United States

Disclosure(s):

Brian Badgwell, MD, MS: No financial relationships to disclose

Introduction: The purpose of this phase I trial was to evaluate the safety and toxicity of preoperative short-course chemoradiotherapy (CXRT) in patients with potentially resectable gastric or gastroesophageal adenocarcinoma as part of a total neoadjuvant therapy (TNT) approach.

Methods: Patients with potentially resectable gastric or gastroesophageal adenocarcinoma received CXRT consisting of 30 Gy in 10 fractions with concurrent capecitabine or fluorouracil, followed by systemic therapy for 2 months and then surgery. The primary objective was safety of CXRT with secondary endpoints of pathologic complete response, perioperative complications, and overall survival (OS).

Results: A total of 24 patients were treated between March 2021 and December 2022. Ten patients (42%) presented with bleeding and 3 (13%) presented with gastric outlet obstruction. Two patients (8%) had cirrhosis. Clinical nodal involvement was reported in 12 patients (50%). Twenty patients (83%) had poorly differentiated tumors, and 13 (54%) had signet ring cell histology. All patients completed CXRT. CXRT treatment-related toxic effects included grade 3 lymphopenia in 7 patients (29%), grade 4 lymphopenia in 1 (4%), and grade 3 anemia in 1 (4%). After CXRT, 22 patients (92%) completed 2 months of chemotherapy, 1 patient (4%) with a microsatellite-high tumor completed immunotherapy, and 1 patient (4%) underwent resection without systemic therapy. All patients underwent attempted resection, and gastrectomy was performed in 20 (83%). R0 resection rate was 95%. Pathologic complete response was observed in 2 patients (8%), and ≤ 1% viability was observed in an additional 4 (17%). Three patients had surgical complications (grade I in 1 patient [4%], grade IIIb in 1 [4%], and grade IVa in 1 [4%]); there were no deaths within 90 days. The median follow-up time was 20 months, and median OS was not reached. One- and 3-year OS rates from the date of diagnosis were 96% and 80%, respectively.

Conclusions: Short-course CXRT (30 Gy in 10 fractions) may be safely used as part of a planned TNT approach. Rates of treatment completion, pathologic response, and survival were promising, supporting further research into TNT for gastric cancer.

Learning Objectives:

understand the concept of total neoadjuvant therapy for resectable gastric cancer.
understand the sequence of chemotherapy and radiation prior to gastrectomy.
describe the adverse events associated with total neoadjuvant therapy for gastric cancer.