EP169 - Predicting Tumor Regrowth in Patients Undergoing Watch-and-Wait Surveillance After Total Neoadjuvant Therapy

Saturday, May 10, 2025

3:53 PM – 3:58 PM PT

Location: Monitor 9, Sails Pavilion, Upper Level

ePoster Presenter(s)

Kamil Erozkan, MD

Research Fellow
University Hospitals Cleveland Medical Center, Department of Surgery, Division of Colorectal
Cleveland, OH, United States

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

Author(s)

ES

Emily F. Simon, MD (she/her/hers)

General Surgery Resident
University Hospitals Cleveland Medical Center, Department of Surgery
Cleveland, OH, United States

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

Satish E. Viswanath, PhD

Associate Professor
Case Western Reserve University
Cleveland, Ohio, United States

Disclosure information not submitted.
Ronald Charles, MD (he/him/his)

Assistant Professor of Surgery
University Hospitals Cleveland Medical Center, Department of Surgery, Division of Colorectal
Cleveland, OH, United States

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

Lauren Henke, MD

Associate Professor of Radiation Oncology
University Hospitals
Cleveland, Ohio, United States

Disclosure information not submitted.
JS

Jennifer Selfridge, MD, PhD

Assistant Professor
University Hospitals Cleveland Medical Center
Cleveland, Ohio, United States

Disclosure information not submitted.
Meagan Costedio, MD (she/her/hers)

Co-Chair of Surgery and Medical Director of Colorectal Surgery at Ahuja Medical Center
University Hospitals Ahuja Medical Center
Case Western University
Beachwood, OH, United States

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

Senior Author(s)

ES

Emily Steinhagen, MD, FACS, FASCRS

Associate Professor of Surgery
University Hospitals Cleveland Medical Center, Department of Surgery, Division of Colorectal
Cleveland, Ohio, United States

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

All of the relevant financial relationships listed below have been mitigated.

Kamil Erozkan, MD: This individual has no financial relationships with ineligible companies.

Emily F. Simon, MD: This individual has no financial relationships with ineligible companies.

Ronald Charles, MD: This individual has no financial relationships with ineligible companies.

Meagan Costedio, MD: This individual has no financial relationships with ineligible companies.

Emily Steinhagen, MD, FACS, FASCRS: This individual has no financial relationships with ineligible companies.

Image or Table (Do Not add text here): Table 1: Univariate anaylsis between patients with sustained WW and patients with regrowth

Purpose/Background: Total neoadjuvant treatment (TNT) has become the standard of care for locally advanced rectal cancer (LARC), leading to increased rates of complete clinical response and expanding the potential for organ preservation through watch-and-wait (WW) protocols. Despite these advances, tumor regrowth remains a concern, necessitating vigilant surveillance. However, optimal surveillance protocols are unknown, and factors predicting tumor regrowth during WW have not been well defined. This study aims to identify predictors of tumor regrowth in patients undergoing WW after TNT.

Methods/Interventions: We conducted a retrospective review of patients with LARC who completed TNT at a single institution between 2019 and 2024. Patients who achieved sustained complete clinical response (cCR) for at least 12 months, as well as those who experienced tumor regrowth following cCR, were included. Patients with suspected regrowth who subsequently underwent surgery and were found to have a pathologic complete response (pCR) were excluded. Univariate analyses were performed to compare demographic, histopathologic, biochemical, clinical, radiological, and treatment-related factors between patients who experienced tumor regrowth and those who did not.

Results/Outcomes: Among 137 patients with LARC, 44 patients (32.1%) achieved cCR following completion of TNT. Of these, 10 patients experienced tumor regrowth and subsequently underwent surgery, with histopathology revealing a pCR in 2 cases.
In total, 20 patients sustained cCR, with the remainder excluded due to limited follow up. A total of 28 patients (25% female) with a mean age of 62.4 years (±13) were included in the univariate analysis. However, no statistically significant differences were observed in demographic, histopathologic, biochemical, clinical, radiological, or treatment-related factors between patients who experienced tumor regrowth and those who did not (Table 1).

Conclusion/Discussion: The study did not identify any predictors of tumor regrowth in patients undergoing WW surveillance following TNT. Nevertheless, this area warrants further investigation to better tailor surveillance strategies and optimize recommendations for non-operative management.