# Conversion surgery vs. standard of care in pancreaTic cancer oligometastatic to the liver (SONAR: Surgery in Oligometastatic paNcreatic cAnceR) a randomized controlled trial

**Authors:** Riccardo Guastella, Giampaolo Perri, Domenico Bassi, Nicola Canitano, Virginia Padoan, Samuele Grandi, Riccardo Pellegrini, Letizia Procaccio, Francesca Bergamo, Sara Lonardi, Riccardo Carandina, Enrico Gringeri, Giovanni Marchegiani, Umberto Cillo

PMC · DOI: 10.1186/s12885-025-15183-9 · BMC Cancer · 2026-01-12

## TL;DR

This trial compares surgery to standard care for pancreatic cancer patients with limited liver metastases after chemotherapy.

## Contribution

The study introduces a randomized controlled trial to evaluate surgery's role in oligometastatic pancreatic cancer.

## Key findings

- Patients will be randomized to surgery or observation/chemotherapy continuation.
- The primary outcome is two-year overall survival.
- The trial aims to refine treatment strategies for this challenging disease.

## Abstract

Pancreatic cancer oligometastatic to the liver represents a distinct subset of advanced disease, presenting a limited number of metastases in a single site. First-line chemotherapy is considered the standard of care, with a poor overall prognosis. However, the optimal strategy for oligometastatic patients presenting response or stability after treatment is unclear. In selected patients, surgical resection is associated with prolonged survival, according to retrospective series. The aim of this randomized clinical trial is to compare the efficacy and safety of surgery versus observation or continuation of chemotherapy in patients with resectable pancreatic cancer oligometastatic to the liver with stable disease or response after first-line chemotherapy.

The study is a phase-2 multicentric randomized controlled trial with 1:1 allocation ratio. Patients diagnosed with pancreatic cancer and a limited number (up to 3) of liver metastases, with no evidence of extrahepatic disease, who received systemic chemotherapy as the initial treatment and with disease response or stability after therapy will be considered eligible patients. Patients will be randomized to either Arm A (surgery) or Arm B (observation or continuation of chemotherapy). The primary outcome will be overall survival at two years, with secondary outcomes including progression-free survival, treatment-related adverse events, quality of life and translational analyses.

This randomized controlled trial will evaluate the role of surgery in pancreatic cancer oligometastatic to the liver after response or stability to first-line chemotherapy. While systemic therapy remains the standard of care, selected patients may benefit from surgical resection. By comparing surgery to observation or continuation of chemotherapy, the SONAR trial aims to fill a critical gap in treatment strategies and potentially refine the management of this challenging disease.

The trial has been registered at ClinicalTrials.gov on 15/11/2024 before inclusion of the first patient (NCT06690528).

## Linked entities

- **Diseases:** pancreatic cancer (MONDO:0005192)

## Full-text entities

- **Diseases:** liver metastases (MESH:D009362), extrahepatic disease (MESH:D001651), Pancreatic cancer (MESH:D010190)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Full text

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## Figures

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Source: https://tomesphere.com/paper/PMC12794266