Role and Limit of Endoscopic Ultrasonography in Staging for Esophageal Cancer

Kang, Jin Kyung; Park, In Suh; Chung, Jae Bock; Song, Si Young; Park, Seung Woo; Lee, Yong Chan; Lee, Sang Gil; Moon, Yeong Myung

Abstract

BACKGROUND
Despite the technical developments in diagnosis and therapy, esophageal cancer is highly lethal disease and the survival is largely dependent upon the stage of the disease. Preoperative cancer staging is crucial in choosing a therapeutic option as well as in predicting the prognosis of the patients. Staging has been based on computerized tomography (CT) and transabdominal ultrasonography. However CT has a limit in pre-cisely discriminating the depth of invasion or the lymph node metastases. With the devel-opment of endoscopic ultrasonography (EUS) and with its superiority in delineating wall structure and detecting lymph node metastases, its usefulness in staging for esophageal cancer has been cknowledged. In order to evaluate the accuracy of EUS, we compared EUS with pathologic findings in patients with esophageal carcinoma.
METHODS
From July 1990 to August 1997, 136 patients with esophageal cancer received preoperative cancer staging with EUS. Among them, 48 patients who underwent surgical procedures with the intention of radical resection were included. We compared the EUS and pathologic find-ings and analysed the accuracy of EUS for preoperative staging.
RESULTS
The overall accu-racy of EUS for T-staging was 43.8%. Twenty five percents of the patients (12/48) pre-sented high-grade tumor strictures, which precluded the passage of the endoscope. There was no statistical significance according to tumor site, size or gross morphology. However theaccuracy was significantly lower in tumors with ulceration than in tumors without ulceration (35.3% vs 64.3%, p=0.004). Mainly, ulceration in tumors caused significant overstaging of the T-stage. In the assessment of regional lymph node metastasis, the overall accuracy achieved by EUS was 66.6%; the sensitivity was 95.5%, specificity 42.3%, positive predictive value 58.3%, and negative predictive value 91.7%. Tumors with more than 2 lymph nodes rendered more accurate N-staging than tumors with less than 2 lymph nodes.
CONCLUSIONS
In conclusion, the accuracy of the EUS for preoperative staging of esophageal cancer was not satisfactory, mostly influenced by ulceration in tumors and its resultant inflammatory reactions around the tumors, therefore more systematic study will be needed to establish the precise diagnostic criteria of EUS staging.