Pancreatic adenocarcinoma patients with pain have abnormal central pain processing

Pancreatic ductal adenocarcinoma (PDAC) is often associated with debilitating abdominal pain that is poorly understood. The aim of this study is to evaluate pain processing in patients with PDAC using Pancreatic Quantitative Sensory Testing (P-QST).

We conducted a cross-sectional study enrolling histologically confirmed PDAC patients from referral centers in the United States and Germany, and healthy controls from the United States, Germany, and Denmark. P-QST assesses central pain processing by measuring pressure pain thresholds at dermatomal sites (C5, T10 back, T10 abdomen, L1, L4), evaluating temporal summation with pinprick stimulation, and using a cold pressor test with a conditioned pain modulation (CPM) paradigm. Using an established algorithm, it differentiates normal pain processing from segmental (pancreatic dermatome-related) hyperalgesia and widespread hyperalgesia.

A total of 104 patients with painful, treatment-naive PDAC (56.7% men, mean age 65.9 ± 10.6 years) and 122 healthy controls (50% men, mean age 48.9 ± 12.1 years) were enrolled. PDAC patients were 29% early tumor stage (I/II) and 71% advanced tumor stage (III/IV). Overall, PDAC patients had lower pressure pain thresholds, higher temporal summation and shorter cold pressor endurance time compared to controls. Abnormal central pain processing, i.e., segmental hyperalgesia (19% vs. 12%) and widespread hyperalgesia (19% vs. 4%), was significantly more common in PDAC patients (p < 0.001). Advanced tumor stage and metastases were associated with lower CPM and more widespread hyperalgesia, Advanced tumor stage and metastases were associated with lower CPM and more widespread hyperalgesia, though not remain significant after false discovery rate correction.

P-QST revealed abnormal central pain processing in PDAC patients compared to healthy controls, which may have implications for pain management.