Background: Differences in the extent and quality of surgical resection for esophageal cancer may influence the pathological staging and patient outcome. There are no data in the literature qualitatively and/or quantitatively characterizing esophagectomy specimens.
Methods: Macroscopic images of 161 esophagectomy specimens were analyzed retrospectively. The extent of resection was qualitatively classified as "muscularis propria," "intra-meso-esophageal," or "meso-esophageal." The volume of meso-esophageal tissue was quantified morphometrically. The number of muscle defects per specimen was counted. Results were related to clinicopathological variables, including survival.
Results: Sixty-two (39%) specimens were classified as "muscularis propria," 65 (40%) as "intra-meso-esophageal," and 34 (21%) as "meso-esophageal." The morphometrically measured meso-esophageal tissue volume was different between the three types (P < 0.001). The specimen type was related to the total number of lymph nodes (P = 0.02), number of metastatic lymph nodes (P = 0.024), and depth of tumor invasion (P = 0.013), but not related to extramural tumor volume, circumferential resection margin status, or the surgeon performing the resection. The number of muscle defects per specimen was similar in all resection types. The resection specimen classification was related to survival in patients treated by surgery alone (P = 0.027).
Conclusions: This is the first study to quantify and classify the volume of tissue resected during esophagectomy. Our study shows significant variation of the resected tissue volume impacting pathological tumor staging. This variation was not associated with individual surgeon performance. A prospective, multicenter study is needed to validate our results and to investigate the potential biological mechanisms influencing the resectable volume of meso-esophageal tissue in cancer patients.