Interobserver variation in tumor staging.

Interobserver agreement in cardioesophageal and rectal tumor evaluation is generally good, especially for uT1 and uT4 tumors. Diagnosis of a uT2 tumor is difficult and results in poor agreement. However, the proportion of agreement is satisfactory for distinguishing tumors that invade the mediastinal or the perirectal fat from those that do not, a situation that may be the most relevant from a therapeutic point of view. In cases of cardioesophageal tumor, agreement for metastatic LN is lower and depends on the sites involved, with the best agreement for intra-abdominal LN, which may indicate a worse prognosis. Lack of agreement in EUS images can be avoided by precise manipulation of the echoendoscope in the upper part of the mediastinum and by improving training and the definitions regarding EUS.