The goal of this clinical trial is to explore the value of molecular residual disease (MRD) monitoring based on ctDNA in borderline resectable or locally advanced pancreatic cancer. The main questions it aims to answer are:
* prognostic value of baseline MRD; * the role of MRD dynamic changes after treatment in guiding treatment. Peripheral blood derived from participants will be obtained for MRD test before conversion therapy initiation and at the first imaging assessment after chemotherapy.
patients with histologically confirmed borderline resectable or locally advanced pancreatic cancer;
conversion therapy was planned;
both sexes, age ≥18 years old;
ECOG performance status score ≤2;
a known diagnosis of pancreatic cancer other than ductal adenocarcinoma;
treated with any systemic antitumor treatment before first-line chemotherapy onset;
died or lost to follow-up within one month after the initiation of first-line chemotherpay;
combined with other primary malignances.