Ability of computed tomography and endoscopic ultrasound to predict pathological tumor node metastasis staging of resected ampullary carcinomas (ACs): an analysis of the Fédération Française de Cancérologie Digestive AC prospective cohort study

BACKGROUND AND AIMS: Pretherapeutic evaluation of ampullary carcinomas (ACs) is important to choose the optimal therapeutic strategy. We aimed to assess the ability of EUS and CT to predict the pathologic tumor node metastasis stage of resected AC. METHODS: We analyzed data collected in the Fédération Française de Cancérologie Digestive AC cohort, a French multicentric prospective cohort of patients with resected AC. Our main outcome was the diagnostic performance of EUS to predict pathologic tumor (pT) and pathologic node (pN) and CT to predict pN. RESULTS: Among the 389 patients included in the cohort, data for ultrasound tumor staging, ultrasound node staging, and CT node staging, along with pathology results, were available for 143, 160, and 185 patients, respectively. For pT1 prediction, values for sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV) were 68%, 87%, 53%, and 93%, respectively, for EUS, with an accuracy of 84%. For pT2 prediction, values were 58%, 75%, 56%, and 75%, respectively, with an accuracy of 68%. For pT3-T4 prediction, values were 62%, 79%, 71%, and 71%, respectively, with an accuracy of 71%. For pN0 prediction, values for Se, Sp, PPV, NPV, and accuracy were 88%, 38%, 60%, 75%, and 64%, respectively, for EUS, and 94%, 39%, 63%, 85%, and 68%, respectively, for CT. CONCLUSIONS: Although the overall performance of both modalities was low, we found that both EUS and CT had good NPV for the prediction of pN0, and EUS had a good NPV for predicting pT1.