274 TIME TO PROGRESSION TO AFP AS A PREDICTOR OF SURVIVAL IN PATIENTS WITH HEPATOCELLULAR CARCINOMA TREATED WITH SORAFENIB

surgery.The individual response to TACE is mostly unpredictable, and to date, only the tumor diameter has been suggested as a helpful predictor, with ≤3 cm HCC less likely to respond.Aim of the present study is to identify tissue TACE predictors of response, to be used in the clinical practice, possibly also on pretreatment liver biopsies.Materials and Methods: Forty-one patients with HCC underwent liver explantation or resection following TACE.Clinico-pathological data and surgical specimens were available in all the cases.Nineteen HCC liver biopsies obtained before TACE from the same patients were also available.We investigated the expression of markers involved in adaptive mechanisms to hypoxia (CD34 for microvessel density, HIF-1a, VEGF, CAIX) and then we evaluated their association with tumor necrosis, histologically assessed, in the resection specimens.On the basis of the extent of necrosis we defined two groups of nodules, namely the TACE low responders (TLR, ≤50% necrosis) and TACE high responders (THR, >50% necrosis).Results: In surgical specimens 45/103 (44%) nodules were classified as TLR.Of these 45 nodules, 33 (73%) had a diameter ≤3 cm, 28 (62%) showed a high microvessel density, 30 (66%) CAIX hyperexpression and 40 (89%) VEGF hypoexpression (p < 0.05).While none of these parameters, individually taken, was able to predict with sufficient accuracy a TACE low response, their combination resulted more effective.The association of at least 3 of these parameters, regardless which one, was able to predict a TACE low response with 73% sensitivity, 76% specificity and 74% accuracy.When also applied to pre-TACE liver biopsy the model showed 100% sensitivity, 78% specificity and 89% accuracy.Conclusions: This study identifies potential tissue markers (VEGF, MVD, and CAIX) able to predict, in combination with the tumor size, the effectiveness of TACE in the treatment of individual HCC.The evaluation of these markers on liver biopsies before chemoembolization may be helpful to optimize patient selection and the recall policy during follow up.