Tumor Mutation Profiling in Bile Samples From Patients With Biliary Strictures Related to Pancreatico-biliary Cancers

The differential diagnosis between benign and malignant bile duct strictures is a difficult and demanding task for clinicians. Clinical, biochemical, and radiological characteristics of malignant biliary strictures are non-specific and tissue diagnosis is difficult to obtain preoperatively. For this reason, there is a need for the development of new diagnostic modalities. Of particular interest is the quest of tumor markers secreted or shed in bile by tumor cells developing in the biliary tract.

In addition, patient's tumor molecular profile is the basis for selecting personalized therapy. Cholangiocarcinomas are characterized by a large genetic heterogeneity. The most frequent mutations are TP53, KRAS, BRAF, EGFR, MET, NRAS, PIK3CA, ERBB2, SMAD4, FBXW7, ARID1A, PBRM1, BAP1 et IDH1/2. In the case of pancreatic cancers, the most frequent are KRAS mutation detected in 90 % of the patients and CDKN2A, SMAD4, TGFBR1, TGFBR2, ATM, BRCA2, MLL2, MLL3, KDM6A, ARID1A, ARID1B, SMARC1, GNAS and RNF43 mutations.

It is well established that KRAS and P53 mutations can be detected in bile samples from patients with biliary strictures related to cholangiocarcinoma and cancer of the head of the pancreas. The main objective is to determine if bile sample analysis from patients with malignant biliary stricture may allow to identify tumor mutation profile and determine tumor genotype. A secondary objective is to evaluate the diagnostic value of Vascular Endothelial Growth Factor (VEGF) and metallo-proteinases (MMPs) levels in bile samples.

Tumor genotyping will be performed in bile samples (supernatant and cell pellet) and tumor tissues in a series of 10 patients surgically treated for malignant biliary stricture related to cholangiocarcinoma or cancer of the head of the pancreas. The biochemical markers, VEGF and MMPs, will be assessed in bile samples obtained during endoscopic retrograde cholangiopancreatography in 50 patients with malignant biliary stricture and 50 patients treated for benign biliary diseases.