Different accuracy of endosonographic tumor staging after neoadjuvant chemotherapy and chemoradiotherapy in esophageal cancer

Abstract

Treatment response to neoadjuvant therapy is histologically associated with more or less intensive inflammation and fibrosis. In consequence, accuracy of endosonographic TN-tumor staging after neoadjuvant treatment is hampered. We analyzed whether the kind of treatment chosen [chemoradiotherapy (CRT) or chemotherapy (CT)] differently influences the accuracy of endoscopic ultrasound after neoadjuvant therapy in esophageal cancer. We performed serial endoscopic ultrasound examinations in 18 patients after neoadjuvant CRT and 30 patients after neoadjuvant CT. TN-stage was classified according to the standard parameter. Histological examination of the surgical resection specimen served as gold standard. The most frequent error was overstaging, especially in patients with complete tumor response or minimal residual disease. Accuracy of T-staging was significantly worse after CRT (0.16) than after CT (0.43), obviously due to difficulty in distinguishing residual tumor from treatment-associated fibrosis and inflammation. Accuracy of N-staging was also hampered, but to a less extent (sensitivity/specificity 0.85/0.36 after CRT, and 0.5/0.42 after CT). Accuracy of endosonographic TN-tumor staging is significantly more hampered by neoadjuvant CRT than after CT. However, endoscopic ultrasound is insufficient for TN-staging irrespective of the kind of neoadjuvant therapy performed.