Histological classification of gastric cancer from initial to advanced stages.

An ideal classification of malignant tumors should imply not only the histogenesis of the tumor and adequate reproducibility of its specific characteristics by other investigators, but also an exact definition of the stages of tumor development to facilitate prognostic prediction. The present paper proposes a classification of gastric carcinoma with emphasis on the initial stages of malignant transformation. The classification is based on the analysis of early invasive gastric cancer observed in biopsy material from the Institute of Pathology of Münster University. Since 1974, all cases of severe dysplasia or early gastric cancer were selected from a total of 200,000 gastric biopsies and more than 1500 gastric resections, and subjected to special work-up. In analogy to Clark's classification of malignant melanoma (Clark et al., 1969) the proposed classification defines consecutive stages of development in gastric carcinoma with special regard on the maximum depth of invasion and vertical thickness of the tumor, together with its histologic type and the predominant direction of tumor spread.