ctDNA Monitoring After Pancreatic Cancer Surgery (K-4CARE Lite Study)

Pancreatic ductal adenocarcinoma (PDAC) carries one of the worst prognoses among solid tumors. Even after curative-intent resection, 70-80% of patients recur within two years. Current post-operative surveillance relies on computed tomography (CT) imaging and the serum tumor marker CA 19-9, but both have limited sensitivity for detecting microscopic residual disease. This single-center, prospective observational study evaluates the use of the K-4CARE Lite platform-a tumor-informed plus tumor-agnostic circulating tumor DNA (ctDNA) assay with a limit of detection of 0.005%-for dynamic monitoring of minimal residual disease (MRD) in patients with resected PDAC. Thirty adult patients who have undergone R0 or R1 (margin \<1 mm) resection at Linkou Chang Gung Memorial Hospital will be enrolled over 24 months. Each participant will provide one baseline tumor tissue sample (formalin-fixed paraffin-embedded) and three serial blood samples at three pre-specified study timepoints: Timepoint 1 (Week 4 to Week 10 after surgery, before adjuvant chemotherapy); Timepoint 2 (12 weeks after Timepoint 1, approximately 3 months into adjuvant chemotherapy); and Timepoint 3 (at completion of adjuvant chemotherapy, approximately Month 6 after surgery). A fourth long-term follow-up phase (Timepoint 4) collects results from patient-funded ctDNA testing performed as part of routine care. The primary outcome is the cumulative MRD detection rate across the three pre-specified post-surgical timepoints (Timepoint 1, Timepoint 2, and Timepoint 3). Secondary outcomes include the association between ctDNA status and disease-free survival (DFS) and overall survival (OS), molecular clearance rate at Timepoint 3, lead time of molecular relapse over imaging, and platform performance. ctDNA results are reported back to the treating physician for reference but do not mandate treatment changes-all clinical decisions remain at the physician's discretion per standard guidelines. This study aims to generate the prospective evidence base needed to design future ctDNA-guided interventional trials in pancreatic cancer.

Sex

All

Minimum age

20 Years

Inclusion Criteria:

* Age 20 years or older
* Histologically confirmed pancreatic ductal adenocarcinoma (PDAC), including its histological subtypes
* Has undergone curative-intent resection (R0 or R1, defined as margin \<1 mm), via pancreaticoduodenectomy, distal pancreatectomy, or total pancreatectomy
* Post-operative pathologic stage at least pT1, with N0 or N1 or higher
* Computed tomography (CT) or magnetic resonance imaging (MRI) within 4 weeks before enrollment confirming no evidence of residual tumor and no distant metastasis
* Intent to receive adjuvant chemotherapy
* Sufficient surgical FFPE tumor tissue available for genomic sequencing
* Able to understand and provide signed informed consent
* Patients with or without prior neoadjuvant chemotherapy are both eligible

Exclusion Criteria:

* Post-operative pathologic stage IV (distant metastasis), or R2 resection
* Concurrent active primary malignancy (except cured non-melanoma skin cancer or carcinoma in situ within the past 5 years)
* Severe post-operative complications precluding initiation of adjuvant chemotherapy within 12 weeks
* Receipt of post-operative radiation therapy
* Known hematologic disease or myeloproliferative disorder that may significantly affect ctDNA assay accuracy
* Pregnant or breastfeeding women
* Unable to comply with the protocol-specified blood draw schedule

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