Preoperative level of serum transthyretin as a novel biomarker predicting survival in resected pancreatic ductal adenocarcinoma with neoadjuvant therapy.

Background: Systemic inflammation and altered metabolism are essential hallmarks of cancer. We hypothesized that the rapid turnover protein transthyretin (TTR) (half-life: 2-3 days), compared with the conventional marker albumin (21 days), better reflects the inflammatory/metabolic dynamics of pancreatic ductal adenocarcinoma (PDAC) after neoadjuvant therapy (NAT) and is a useful prognostic marker.

Methods: Serum TTR and albumin levels were measured in 104 consecutive post-NAT PDAC patients before curative resection. The associations of preoperative TTR and albumin levels with overall survival (OS) after pancreatectomy were retrospectively analyzed.

Results: The mean (SD) TTR and albumin levels were 21.6 (6.4) mg/dL (normal range: ≥22.0 mg/dL) and 3.9 (0.55) g/dL. A low (<22.0 mg/dL) post-NAT TTR level was associated with an advanced tumor stage and higher CEA and CRP levels. Patients with low TTR levels showed significantly worse OS compared with normal levels (3-year OS 39 % vs. 54 %, P = 0.037), although albumin levels did not. We modified prognostic biomarkers of systemic inflammation/metabolism, such as GPS, PNI, and CONUT scores, using the serum TTR instead of albumin level and successfully showed that modified scores were better associated with OS compared with original scores using serum albumin level.

Conclusions: Our data suggest that the TTR level is a promising prognostic biomarker for PDAC patients after NAT.