Burden Of Undergoing Eus-Mri Based Pancreatic Cancer Screening In High-Risk Individuals; First Experiences

Colorectal cancer (CRC) is the second most frequent cause of cancer-related death in Western countries: one third of CRC is represented by rectal cancer (RC). Accurate staging is recommended to provide an optimal treatment strategy. Neoadjuvant chemoradiotherapy (NCRT) is increasingly used in the treatment of advanced RCwith the intention of downsizing and downstaging the tumour and to reduce tumour recurrence. Accuracy of EUS staging is reported to be 75-94% for tumour penetration and 7283% for nodal metastases. However after NCRT the EUS accuracy for T staging may decrease (50%) because marked fibrosis, peritumoral infiltration of inflammatory cell necrosis. AIMS: the aims of this study was to verify the accuracy of EUS in restaging RC after neoadjuvant CRT and the efficacy of the therapy in the downstaging and downsizing the tumour. METHODS: we prospectively enrolled consecutive patients affected by RC in stage II-b and III who underwent EUS and MRI or CT or PET before and after neoadjuvant CRT. EUS scanning was performed by one endosonographer using an electronic radial ecoendoscope (Olympus GF UE 160-AL5) with imaging at 7,5-10 MHz. Patients underwent surgical resection after reassessment staging. The reduction of diameter of RC was evaluated using RECIST criteria. Pathological staging was undertaken according to the TNM classification. RESULTS: 14 patients with locally advanced RC were assessed: 10 male, median age 64 yrs (range 56-73). The median distance from the anus was 5 cm. Seven patients were in in stage II-b and 7 in stage III. All patients underwent radiotherapy with no complication associated with chemotherapy (10 pts with CDDP, 2 pts with FOLFOX and 2 pts with FUFA). The downstaging after neadjuvant therapy was observed in 7/14 patients, and significant reduction of tumor diameter in 13/14 patients. There were 13 anterior resections and 1 abdominoperineal resections. EUS post-NCRT T stage was correct in 11/14 pts (3 T0, 5 T3, 3 T2), while 3 pts were over staged (2 T2 and 1 T1). Overall accuracy of EUS post-RCT for pathologic T stage was 93% for T0-T1 stage and 86% for T3 stage. EUS accuracy for N-stage was 79%. CONCLUSION: in our preliminary study neoadjuvant CRT was useful to downstage and downsize locally advanced RC. EUS seems to be an accurate tool to restage RC after neoadjuvant CRT. However our results needed to be confirmed in a large cohort of patients with locally advanced RC.