A few studies reported that AFP may be
helpful for detection of HCC recurrence in patients with high pretreatment serum AFP levels.[3, 4] Particularly, in patients with a high pretreatment serum AFP that normalized after treatment, the subsequent elevation of AFP may suggest tumor recurrence or progression. Therefore, the purpose of this study is to evaluate the diagnostic performance of serum AFP in detecting HCC recurrence after radiofrequency ablation (RFA), both in patients with high pretreatment AFP (AFP-producing HCC) levels and in patients with normal Selleck Napabucasin pretreatment AFP (non-AFP-producing HCC) levels. In addition, the false positive and true positive AFP results were analyzed to determine feasibility of improving the diagnostic performance of AFP after adjusting for significant confounding Proteasome inhibitor factors. Institutional Review Board approval was obtained for this retrospective study and the requirements for informed consent
were waived. The study was performed in compliance with the Health Insurance Portability and Accountability Act, United States 1996. From a database of patients with HCC who underwent RFA from January 1999 to September 2012, we selected those with solitary HCC, who had available follow-up by contrast-enhanced computerized tomography (CT) or magnetic resonance imaging (MRI) at our institution (See below “imaging follow-up and end point determination”), and who had available and adequate AFP measurements (See below “AFP follow-up and abnormal cutoff”). The flow diagram
of patients is shown in Figure 1. Diagnosis of HCC was made either by using the AASLD imaging criteria guidelines, or by pathological confirmation of HCC on biopsy or surgical resection specimens. A typical diagnostic feature on dynamic CT/MRI included arterial phase hyperenhancement followed by hypoenhancement on the portal venous phase. HCC recurrence on imaging was defined as new nodular enhancement around the ablation site at more than 1 month post-ablation with demonstration Tideglusib of arterial hyperenhancement and venous hypoenhancement, or as interval growth on subsequent follow-up. In cases with rising AFP but no imaging detection, the patients received either a short-term imaging follow-up within 1–2 month or a complimentary contrast study (e.g. if contrast-enhanced CT did not detect recurrence, then the patient was further evaluated with contrast-enhanced liver MRI). At our institution, the protocol for post-RFA follow-up includes CT/MRI within 1 month after the initial treatment, then at 3 months, then every 3 months up to 1 year, and at least every 3–6 months thereafter. The end points were considered in two circumstances. First, if tumor recurrence occurred, the date of imaging that first detected the recurrence was considered the date of recurrence.