Association of endoscopic and CT response with pathological response after preoperative FLOT-based therapy for gastric and gastroesophageal junction cancer: a retrospective cohort study
- 1Department of Medical Oncology, Ankara Bilkent City Hospital
- 2Department of Gastroenterological Surgery, Ankara Bilkent City Hospital
Abstract
Background: Pathological response to preoperative chemotherapy is prognostically relevant in gastric cancer, but reliable estimation before surgery remains challenging. We evaluated the relationship between routine endoscopic and computed tomography (CT) response assessments and major pathological response (MPR) after FLOT-based therapy.
Methods: In this retrospective, single-center cohort study, 450 institutional records were screened and 47 patients with gastric or gastroesophageal junction cancer who underwent gastrectomy after FLOT-based therapy and had evaluable pre- and post-treatment endoscopy were included; 37 also had comparable paired CT assessments. Endoscopic and CT responses were classified as complete, partial, stable, or progressive. Pathology reports were harmonized into complete, near-complete, partial, and poor/no response, and MPR was defined as complete or near-complete response. Discrimination was assessed by receiver operating characteristic analysis, and paired endoscopy and CT areas under the curve (AUCs) were compared using the DeLong test. The combined endoscopy-plus-CT model was exploratory.
Results: MPR occurred in 17 of 47 patients (36.2%), including pathological complete response (pCR) in 10 (21.3%). In the full cohort, endoscopy had an AUC of 0.619 (95% CI, 0.466-0.771) for MPR. In the paired cohort, AUCs were 0.561 (95% CI, 0.379-0.743) for endoscopy and 0.675 (95% CI, 0.501-0.848) for CT (difference, 0.114; p=0.35). The combined model yielded an apparent AUC of 0.692 (95% CI, 0.511-0.873). Both patients with endoscopic complete response had pCR, although this category identified only 2 of 10 pCRs.
Conclusions: Routine endoscopic response showed limited discrimination for MPR. CT had a numerically higher AUC, but the paired comparison was inconclusive, and combining the modalities did not materially improve discrimination. Given the small paired cohort and heterogeneous pathology reporting, these findings are hypothesis-generating. Standardized prospective assessment is required before endoscopic or CT response can be used to estimate pathological response with clinical confidence.
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BibTeX
@article{gencer2026association,
title = {{Association of endoscopic and CT response with pathological response after preoperative FLOT-based therapy for gastric and gastroesophageal junction cancer: a retrospective cohort study}},
author = {Huseyin Gencer and Gokhan Ucar and Efnan Algın and Mehmet Ali Nahit Sendur and Erdal Birol Bostanci},
journal = {Frontiers in Oncology},
year = {2026},
month = oct,
doi = {10.3389/fonc.2026.1960800},
url = {https://www.frontiersin.org/articles/10.3389/fonc.2026.1960800/full},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Association of endoscopic and CT response with pathological response after preoperative FLOT-based therapy for gastric and gastroesophageal junction cancer: a retrospective cohort study
AU - Huseyin Gencer
AU - Gokhan Ucar
AU - Efnan Algın
AU - Mehmet Ali Nahit Sendur
AU - Erdal Birol Bostanci
PY - 2026
DA - 2026/10/16
JO - Frontiers in Oncology
DO - 10.3389/fonc.2026.1960800
UR - https://www.frontiersin.org/articles/10.3389/fonc.2026.1960800/full
AB - Background: Pathological response to preoperative chemotherapy is prognostically relevant in gastric cancer, but reliable estimation before surgery remains challenging. We evaluated the relationship between routine endoscopic and computed tomography (CT) response assessments and major pathological response (MPR) after FLOT-based therapy. Methods: In this retrospective, single-center cohort study, 450 institutional records were screened and 47 patients with gastric or gastroesophageal junction cancer who underwent gastrectomy after FLOT-based therapy and had evaluable pre- and post-treatment endoscopy were included; 37 also had comparable paired CT assessments. Endoscopic and CT responses were classified as complete, partial, stable, or progressive. Pathology reports were harmonized into complete, near-complete, partial, and poor/no response, and MPR was defined as complete or near-complete response. Discrimination was assessed by receiver operating characteristic analysis, and paired endoscopy and CT areas under the curve (AUCs) were compared using the DeLong test. The combined endoscopy-plus-CT model was exploratory. Results: MPR occurred in 17 of 47 patients (36.2%), including pathological complete response (pCR) in 10 (21.3%). In the full cohort, endoscopy had an AUC of 0.619 (95% CI, 0.466-0.771) for MPR. In the paired cohort, AUCs were 0.561 (95% CI, 0.379-0.743) for endoscopy and 0.675 (95% CI, 0.501-0.848) for CT (difference, 0.114; p=0.35). The combined model yielded an apparent AUC of 0.692 (95% CI, 0.511-0.873). Both patients with endoscopic complete response had pCR, although this category identified only 2 of 10 pCRs. Conclusions: Routine endoscopic response showed limited discrimination for MPR. CT had a numerically higher AUC, but the paired comparison was inconclusive, and combining the modalities did not materially improve discrimination. Given the small paired cohort and heterogeneous pathology reporting, these findings are hypothesis-generating. Standardized prospective assessment is required before endoscopic or CT response can be used to estimate pathological response with clinical confidence.
SN - 2234-943X
ER -