The current criteria within the RCP data set is, in part, based on data derived from reports on the surgical treatment of rectal cancer in which circumferential margins of less than 1 mm were found to be prognostically significant.15 The comparison of resectional criteria in esophageal and rectal cancer is likely not appropriate. Despite both viscera being outside the peritoneal reflection and having no serosal covering, the esophagus has no comparable anatomic boundaries, such as the mesorectum or Denonvilliers fascia. In addition, the esophagus lies directly adjacent to organs that cannot be removed with en bloc resection, such as the aorta, spine, heart, and tracheobronchial tree, and immediately adjacent to the pleura, which can be removed en bloc but does not provide a continuous covering for the esophagus. We tend to agree with previous articles9,28- 29 that suggest that positive circumferential resection margins in esophageal cancer are more likely to represent advanced tumor stage rather than a lack of surgical expertise. As a result, surgical resection of a well-defined cancer will predictably have a much higher instance of positive margins in patients with the current RCP system. Studies from the United Kingdom (Table 4) document an incidence of circumferential positive margins between 20% and 47%. Circumferential resection margins have not been routinely assessed in other international studies, but when all patients who were operated on within the present study are included, a positive circumferential resection margin instance of 5% was obtained, which compares well with another large North American study by Barbour et al (n = 505),21 which demonstrated an incidence of positive circumferential margins of 6%. When only T3 tumors are studied, the differences are just as significant. Positive circumferential resection margins according to CAP criteria in the current study were found in 12% compared with 39% to 54% in studies from the United Kingdom using RCP criteria.17,27 The primary issue remains as to which system provides the most clinically relevant prognostic information. The current study attempts to answer this question specifically and though it has the weakness of being a retrospective study, it does have certain design strengths. The study population includes only T3 tumors, which previous series have confirmed is the most pertinent population for comparison.17,22,27,30 Most importantly, though retrospective, all pathologic slides were prospectively rereviewed by a single pathologist with special expertise in gastrointestinal pathology. This provided a consistency in interpretation, measurement, and expertise that is typically lacking in other series. Also, because all operations were done by a single surgeon, there was a consistent approach with respect to tumor resection and lymph node dissection.