Pancreatic cancer is a rare but aggressive malignancy with an increasing incidence in the UK. Due to the late onset of significant symptoms prompting investigation, most patients have metastatic or unresectable locally advanced disease at the time of diagnosis. In patients with localised disease, tumour resection can provide a chance of cure. However, most patients who undergo curative-intent surgery will develop cancer recurrence.
5-aminolevulinic acid (ALA) is a clinically approved fluorescent prodrug that is used for photodynamic diagnostics in malignant glioma and bladder cancer surgery. After either topical or oral ingestion, ALA is taken up preferentially by cancer cells and converted to protoporphyrin IX (PpIX), the fluorescent precursor to haem. ALA in pancreatic cancer surgery could play both a photodiagnostic role (identifying macroscopic residual disease intraoperatively) and a therapeutic role (PDT of the pancreatic bed to reduce local recurrence rates).
Vitamin D is a known differentiating agent for several cell types, and a short high dose course of oral vitamin D supplementation has been shown to enhance ALA-induced fluorescence in an experimental mouse model of skin cancer. Vitamin D has been shown experimentally to influence cancer-associated pancreatic stellate cells to inhibit cancer activation signatures, and low vitamin D levels are associated with poorer survival in advanced pancreatic cancer.
VitPanc-1 is a single centre retrospective study investigating the association between preoperative serum 25-OH vitamin D level and tumour differentiation on postoperative histology of patients undergoing surgery for pancreatic ductal adenocarcinoma (PDAC) over a 10-year period at our unit. Its purpose is to provide preliminary data to plan a prospective study in which patients will be given preoperative vitamin D supplementation to see if this invokes tumour differentiation in PDAC. However, to calculate sample size and determine feasibility, baseline data are required on preoperative vitamin D levels in patients undergoing pancreatic resection for PDAC, as well as whether or not serum levels correlate with histological differentiation.
