88: Optimal Radiation Dose Intensity: Low- vs. High-Dose in the Neo-Adjuvant Treatment of Locally Advanced Esophageal Cancer

Saturday, March 25, 2023

10:46 AM – 10:56 AM

Location: Ballroom B

Abstract Presenter(s)

Nicholas S. Caminiti, MD

Surgical Resident
University of Louisville
Louisville, Kentucky, United States

Disclosure(s): No financial relationships to disclose

First Author(s)

Nicholas S. Caminiti, MD

Surgical Resident
University of Louisville
Louisville, Kentucky, United States

Disclosure(s): No financial relationships to disclose

Author(s)

Prejesh Philips, MD

Associate Professor
University of Louisville, Kentucky, United States

Disclosure information not submitted.
Michael E. Egger, MD, MPH

Associate Professor
Unversity of Louisville
Louisville, Kentucky, United States

Disclosure(s): Iovance Biotherapeutics: Consultant (Ongoing); SkylineDx: Contracted Research (Ongoing)
CS

Charles Scoggins, MD, MDA

Surgical Oncologist
University of Louisville, United States

Disclosure information not submitted.
Robert CG Martin, II, MD,PhD

Professor of Surgery
University of Louisville School of Medicine, Department of Surgery
Louisville, Kentucky, United States

Disclosure information not submitted.

Disclosure(s):

Nicholas S. Caminiti, MD: No financial relationships to disclose

Michael E. Egger, MD, MPH: Iovance Biotherapeutics: Consultant (Ongoing); SkylineDx: Contracted Research (Ongoing)

Introduction: The extent of radiation dose intensity for neoadjuvant chemo-radiation for locally advanced, resectable esophageal adenocarcinoma remains debatable in the USA in the absence of randomized clinical trials, with conventional practice favoring the use of 50.4 vs. 41.4 Gy.

Methods: A review of our prospective gastro-esophageal database was reviewed from 7/2002 to 5/2022 identified patients treated with neoadjuvant chemoradiotherapy. Outcomes were compared between patients undergoing 41.4, 45, or 50.4 Gy. The primary outcomes were pathologic response and overall survival. Secondary outcomes included perioperative mortality adjusted for demographics and clinicopathologic factors. Pathological response to neoadjuvant chemoradiation was assessed with response grade of 0-3; score zero represented a complete treatment effect with no remaining cancer cells seen and score three represented no tumor response.

Results: One hundred and sixty-eight patients were included: 46 (27%) received low-dose ( < 45 Gy) and 106 (73%) received high-dose (50.4 Gy) neoadjuvant radiation. Compared to high-dose, low-dose radiation was associated with superior median overall survival (48.5 vs. 33.5 months) and lower unadjusted 90-day mortality (2.1% vs. 6.8%, all p ≤ 0.01). Multivariable proportional hazards models confirmed an increased hazard of death associated with high-dose radiation therapy (HR = 1.41, 95% CI 1.11–1.73, p = 0.005). There was a significant difference in the rate of pathologic complete response to low-dose vs. high-dose therapy (19% vs 52% p=0.04).

Conclusions: Compared to 50.4 Gy, 41.4 Gy is associated with reduced perioperative mortality and superior overall survival with similar downstaging in locally advanced esophageal cancer. In the absence of randomized clinical data, our findings support the use of 41.4 Gy in patients with chemoradiation followed by esophagectomy. Prospective trials are warranted to further validate these results.

Learning Objectives:

Describe the role of neoadjuvant chemoradiation in locally advanced esophageal adenocarcinoma
Describe the risks and benefits of different neoadjuvant chemoradiation protocols for esophageal adenocarcinoma
Describe the proposed benefit of low dose neoadjuvant chemoradiation for esophageal adenocarcinoma