Carcinoembryonic Antigen, Tumor Response and Quality of Life with Glass Transarterial Radioembolization (TARE) in Liver-Dominant Metastatic Colorectal Cancer Patients: Results from the EPOCH Trial

Sunday, March 5, 2023

3:09 PM – 3:18 PM

Location: Phoenix Convention Center, 227ABC

Presenting Author(s)

Riad Salem, MD

Professor
Northwestern Memorial Hospital

Disclosure information not submitted.

Author/Co-author(s)

RL

Robert Lewandowski, MD, FSIR

Professor
Northwestern University

Disclosure(s):

Robert Lewandowski, MD, FSIR: ABK Biomedical: Consultant (Ongoing); Acerta/AstraZeneca: Advisory Committee or Review Panel Member (Ongoing); BD: Consultant (Ongoing); boston scientific: Consultant (Ongoing), Speaking and Teaching (Ongoing); Varian Interventional Solutions: Consultant (Ongoing)

Purpose: Carcinoembryonic antigen (CEA) is a tumor specific metastatic colorectal (mCRC) biomarker used in therapeutic response assessment and as an early indicator of tumor progression. The relationship between CEA levels and treatment outcomes in patient subgroups from the EPOCH study were examined.

Materials and Methods: EPOCH evaluated the efficacy of second-line treatment with glass TARE + chemotherapy (T+C) vs chemotherapy alone (C) in mCRC patients. Post-hoc analyses identified 2 patient subgroups with greater benefit in progression free survival (PFS), hepatic PFS (hPFS), and time to deterioration of quality of life (TTDQoL) when treated with T+C vs C. The relationship between best overall tumor response rate (ORR) and best percentage change from baseline CEA in Subgroup A (excludes patients with both ECOG 1 and baseline CEA ≥35ng/mL) is presented.

Results:

Subgroup A patients receiving T+C (n=143), had a median PFS of 9.4 months (M), hPFS of 10.8M and TTDQoL of 5.7M vs patients receiving C (n=160), had a median PFS of 7.6M (Hazard ratio (HR): 0.64, 95% confidence interval [CI]=0.47, 0.87; 1-sided p=0.0020), hPFS of 7.6M (HR: 0.53, 95% CI=0.39, 0.73; 1-sided p< 0.0001) and TTDQoL of 3.9M (HR: 0.65, 95% CI=0.46, 0.91; 1-sided p=0.0063). Additionally, the CEA percentage change from baseline was found to impact the treatment effect (T+C or C) on TTDQoL (2-sided p=0.0061 from a Cox regression interaction test). CEA response and ORR in Subgroup A patients with baseline CEA > 5 ng/mL are shown below. Similar results, with a larger difference, were seen in a smaller Subgroup B (patients with KRAS-wild type and ECOG 0 or CEA< 35 ng/mL).

Conclusion:

Subgroup analysis identified patients with further improved outcomes, including TTDQoL, for T+C vs C. More patients with baseline CEA >5ng/mL treated with T+C had a CEA reduction consistent with a better ORR with T+C vs C, supporting CEA use as an early marker for tumor response and progression with T+C.

*IDE #G100322

PI# 1429907-AA