PANCREATIC CANCER ANGIOGENESIS ASSESSMENT BY CONFOCAL LASER ENDOMICROSCOPY AND ANTI-CD105 ANTIBODY IN PANCREATIC CANCER – A PILOT STUDY

Aims:

Pancreatic ductal adenocacinoma (PDAC) remains one of the most aggresive types of cancer with a limited number of therapeutic options. Confocal laser endomicroscopy (CLE), with various miniprobes available is accessible tool for different lesions providing a live diagnosis. To assess neoangiogenesis PDAC diagnosed patients by two fluorescently labeled antibodies on fresh biopsy samples imaged with CLE.

Methods:

Ten consecutive patients diagnosed with PDAC following FNA -endoscopic ultrasound underwent curative therapy with tumor resection. Fresh specimens were washed in saline solution and incubated for one hour in the dark at 37 °C, with Alexa-Fluor 488 anti-CD105/Endoglin antibody (mouse anti-human IgG2a, Exbio Prague, Czech Republic). We also tested mesothelin as positive for PDAC. CLE imaging was performed to assess the microvascularazation in an ex vivo setting by direct contact with the specimen. All aquired images were assessed with a dedicated processing software to obtain a Z projection of confocal serial stacks. Next we measured the vascular density and vessel diameters within 50 µm × 475 µm rectangular regions previosuly chosen. We also compared the results with clasic immunohistochemistry technique.

Results:

CD105 expression on CLE was present within PDAC samples with a microvascular density of 13.56 ± 6.88 compared to normal pancreatic tissue 1.1 ± 0.857 (p < 0.001). Mesothelin was clearly proved to be present in every PDAC samples suggesting a potential direct target for future oncologic therapies.

Conclusions:

This pilot study proves that CLE targeted CD105 for tumoral vascular network might represents a potential tool for future studies regarding PDAC neoangiogenesis and future therapies.