Differences in diagnostic criteria for esophageal squamous cell carcinoma between Japanese and Western pathologists

Abstract

BACKGROUND Large discrepancies have been found between Western and Japanese pathologists in the diagnosis of adenoma/dysplasia versus carcinoma for gastric and colorectal glandular lesions. It is important to determine whether similar differences exist in the diagnosis of esophageal squamous lesions. METHODS Eleven expert gastrointestinal pathologists from Japan, North America, and Europe individually reviewed a set of microscopic slides containing 21 sections of biopsies and corresponding endoscopic mucosal resection specimens from Japanese patients with superficial esophageal squamous neoplastic lesions. The pathologists indicated the pathologic findings on which they based each diagnosis. RESULTS Invasion was the most important diagnostic criterion of carcinoma for the Western pathologists whereas nuclear and structural features were more important for the Japanese pathologists. For two sections showing low grade dysplasia according to most Western pathologists, the Japanese pathologists diagnosed suspected carcinoma in one case and definite carcinoma in the other. For nine sections with high grade dysplasia according to the Western pathologists, the Japanese pathologists diagnosed suspected carcinoma in two cases and definite carcinoma in seven cases. For six sections with suspected carcinoma according to most Western pathologists, the Japanese pathologists diagnosed suspected carcinoma in one case and definite carcinoma in five cases. Four sections showed definite carcinoma according to both the Western and Japanese pathologists. Thus, there was agreement among the Western and Japanese pathologists for only 5 of the 21 sections (kappa value, 0.04). However, when high grade dysplasia, noninvasive carcinoma, and suspected carcinoma were grouped together, the agreement was excellent (19 of the 21 sections; kappa value, 0.75). CONCLUSIONS In Japan, esophageal squamous cell carcinoma is diagnosed mainly based on nuclear criteria, even in cases judged to be noninvasive low grade dysplasia in the West. This difference in diagnostic practice may contribute to the relatively high incidence rate and good prognosis of superficial esophageal carcinoma in Japan. To improve the comparability of research data, the authors recommend that high grade dysplasia, noninvasive carcinoma, and suspected carci‐ noma be grouped together into one category of “noninvasive high grade neoplasia.” [See editorial on pages 969‐70, this issue.] Cancer 2000;88:996–1006. © 2000 American Cancer Society.

Outcome of superficial squamous cell carcinoma of the esophagus: a clinicopathological study

“…Japanese pathologists report the diagnosis of squamous cell carcinoma in lesions, in which, Western pathologists would consider as dysplasia [20][21][22] .…”

Squamous intraepithelial neoplasia of the esophagus: past, present, and future

“…45 On the other hand, the same consensus study as mentioned above has made the superior diagnostic quality of system used by Japanese pathologists evident. 40 Namely, a comparison study between biopsy-based diagnoses and endoscopic mucosal resection-based diagnoses of the same lesion revealed a signifi cant discrepancy among Western pathologists and a high agreement among Japanese pathologists. The differences pathologists pay attention to structural changes of the architecture for the diagnosis of neoplasm.…”

“…In addition, to make a diagnosis of squamous cell carcinoma of the esophagus, nuclear and structural features are more important diagnostic criteria for Japanese pathologists, while invasion of the dysplastic cells into the lamina propria is the most important fi nding for Western pathologists. 40,41 This difference implies that Western among Western pathologists may be due to lack of experience with cases of early squamous cell carcinoma. 40,46 Japanese pathologists have experienced more cases of early invasive carcinoma, in which a low-grade dysplasia-like lesion may invade into the lamina propria, suggesting the presence of basal layer type squamous cell carcinoma in situ (Fig.…”

“…38 Therefore, Japanese pathologists emphasize that the diagnosis of noninvasive squamous cell carcinoma by nuclear fi ndings in biopsy specimens is necessary for the successful early detection and treatment of squamous cell carcinoma. 10,40 This implies that the Western approach may lead to underdiagnosis and delayed treatment, whereas the Japanese approach may cause overdiagnosis and unnecessary treatment. In either case, for both clinical and basic research purposes, an acceptable uniform nomenclature such as noninvasive high-grade neoplasia should be used for high-grade dysplasia, noninvasive carcinoma, and suspected carcinoma.…”

Comparative study of Western and Japanese criteria for biopsy-based diagnosis of gastric epithelial neoplasia

“…In Western countries, gastric cancer (GC) is diagnosed when there is histological evidence of invasion into the lamina propria or beyond the submucosa [1][2][3][4], whereas in Japan and some other countries, diagnosis of GC is based on the degree of structural and cytological abnormality of the tumor glands [4][5][6]. In such a situation, lesions diagnosed as high-grade dysplasia (HGD) by Western pathologists have been diagnosed as GC by Japanese pathologists [2-4, 7, 8].…”