Utilidad clínica del Antígeno Carcinoembrionario (ACE), Tomografía convencional (TC) y PET-CT en el diagnóstico de adenocarcinoma colorrectal recidivante / Clinical utility of Carcinoembryonic Antigen (ACE), conventional tomography (CT) and PET-CT in the diagnosis of recurrent colorectal adenocarcinoma

Introduction: Colorectal cancer is one of the most prevalent tumors in the world. In the surveillance setting of recurrent colorectal cancer, laboratory test like carncinoembryonic antigen (CEA) and imaging tests like computed tomography (CT) and positron emission tomography (PET/CT) are available. We performed this study to establish the predictive accuracy of these tests to an early identification of recurrent colorectal cáncer. Materials and Methods: Thirty six patients at stages I , III and IV, after single metastasis resection of colorectal cáncer were identified. We assessed the utility of CEA, CT and PET-CT in the follow-up of these patients to improve the diagnosis of recurrent disease. Results: Of 36 studied patients, 27 /75%) had recurrence; the median age was 61 year-old and the median lap-time 16 months. The PET PET/CT scan obtained the following results: sensitivity 96.7%, specificity 88.9%, positive predictive value 96.3%, negative predictive value 88.9%, positive likekihood ratio 8.7 and negative likelihood ratio 0.04. Discusion: The best tool to make diagnosis of colorectal cancer and its recurrence is PET­CT, however, none of these tests could make the diagnosis by themselves. It has to be confirmed by histopathologic studies plus other exams.