PROBE-BASED CONFOCAL LASER ENDOMICROSCOPY IS A MANDATORY TOOL IN EVALUATION OF NEOANGIOGENESIS IN LOCALLY ADVANCED GASTRIC CANCER AND IN RECTAL CANCER PATIENTS

Aims:

Probe-based Confocal Laser Endomicroscopy (pCLE) is an advanced endoscopic technique which provides high resolution images of the mucosa and of the microvasculature. The aim of study was to evaluate if pCLE can provide accurate information about tumor vascular pattern before and after neoadjuvant radio-chemoterapy (RT/CT) achieving a more accurate diagnosis and patient-tailored targeted treatment in locally advanced Gastric Cancer (GC) and in Rectal Cancer (RC) patients.

Methods:

130 consecutive RC patients (45F, 85 M mean age: 63 years) and 54 consecutive GC patients (26F, 28 M mean age: 62 years) underwent endoscopy with pCLE-GastroFlex UHD probe and i.v. fluorescein infusion in order to evaluate intratumoral vascularization. After CT/RT treatment, 69 RC (22F, 47 M, mean age: 65years) and 12 GC patients (7F, 5 M, mean age 56 years) were revaluated using pCLE.

Vascular assessment was based on Cannizzaro-Spessotto (CS) scale which evaluated vessel shape, size, permeability and blood flow. The angiogenic score ranged from 0, for normal to 4 for aberrant vasculature.

Results:

79% of RC patients had an angiogenic score 3 or 4 at diagnosis. The angiogenic score after therapy showed a statistical significant improvement (median CS score pre CT: 3.3 vs. median CS score post CT: 1.8) in almost all RC patients (73%). In GC patients we found unchanged vascular alterations which correlated positively with stable or progressive disease. Since in only 25% of GC patients was detected a small remission it was possible that the unaltered angiogenic score could be ascribed to the lack on neoangiogenesis.

Conclusions:

Data demonstrate that during the treatment schedule, pCLE analysis is very important for predicting the efficacy of treatments and possibly introduce anti-angiogenic drugs when necessary. Future studies are necessary for the evaluation of pCLE impact in patients survival. This work was supported by the following grant Ministry of Health RF -2016 – 02361525 to R.C.