Unique Biology of Pancreatic Ductal Adenocarcinoma Accompanied by Rapidly Impaired Diabetes: A Favorable Long-Term Survival Following Curative Resection.

Background: Pancreatic ductal adenocarcinomas (PDACs) are sometimes diagnosed accompanied by rapidly impaired diabetes (PDAC-RID). Although this type of PDAC may have unusual biological features, these features have not been explained.

Methods: Patients with PDAC who underwent upfront pancreatectomy between 2010 and 2018 were retrospectively reviewed. PDAC-RID was defined as a glycated hemoglobin (HbA1c) value of ≥ 8.0% of newly diagnosed diabetes, and acute exacerbation of previously diagnosed diabetes. Other patients were classified as PDAC with stable glycometabolism (PDAC-SG). Clinicopathological factors, long-term survival rates, and recurrence patterns were evaluated.

Results: Of the 520 enrolled patients, 104 were classified as PDAC-RID and 416 as PDAC-SG. There was no significant difference regarding TNM staging, resectability, or adjuvant chemotherapy rate between the groups. However, 5-years cancer-specific survival (CSS) was significantly higher in the PDAC-RID group than in the PDAC-SG group (45.3% vs. 31.1%; p = 0.02). This survival difference was highlighted in relatively early-stage PDAC (≤ pT2N1) (CSS: 60.8% vs. 43.6%; p = 0.01), but the difference was not significant for advanced-stage PDAC. A multivariate analysis of early-stage PDAC showed that PDAC-SG was an independent risk factor of shorter CSS (hazard ratio 1.76; p = 0.02). The hematogenous metastatic rate in early-stage PDAC was lower in the PDAC-RID group than in the PDAC-SG group (18.3% vs. 35.8%; p = 0.01).

Conclusions: PDAC-RID showed a favorable long-term survival rate after curative resection with low hematogenous metastases, which may be due to its unique biology.