Tu2035 Comparison of Hepatocellular Carcinoma (HCC) Tumor Size At Diagnosis in Patients Followed in a Large Academic Liver Center vs. Patients Identified and Referred From the Community

G A A b st ra ct s noted. Cases with positive cytology (with or without FISH test) were excluded. Two experienced cytopathologists examined all cytology specimens and agreed to request FISH testing (performed using UrovysionTM probe in a reference laboratory). Data were presented as percentage, plotted in a 2x2 contingency table and p-value was calculated using Fisher's Exact Test. Results: 18 patients (mean age 66.1 ± 8.7 years; 50% were men) met the inclusion criteria. There were 24 FISH results. 17 were from brushings of stented cases, and 7 were from stent naive cases. 16 out of 24 FISH results were positive. Sensitivities of FISH in diagnosing malignancy in presence of stent, in absence of stent and overall were 58.8% (10/17), 85.75% (6/7) and 66.67% (16/24), respectively. FISH was found to have lower sensitivity in patients with stents. However, sensitivity of FISH was not statistically significantly different between the stent and stent naive groups (p=0.352). These findings are summarized in Table 1 and 2. Conclusions: Negative FISH results in stented patients with indeterminate pancreatobiliary strictures need to be carefully interpreted, as >40% cancers could be missed. Larger studies are needed to provide further information. Table 1: Contingency Table