Histologic features of gastric cancer in relation to patterns of spread

The modes for growth and spread of gastric cancer were investigated in a surgical series of 115 cases--88 of early disease, and 27 involving the muscular layer. In addition, 93 autopsy cases with advanced disease were examined in order to analyze metastatic spread. In cancers of differentiated type in the mucosal layer, changes in histologic features towards the undifferentiated type were observed in the deeper layers, but no histologic transformation was seen in cancers of undifferentiated type. At autopsy distant metastases were common in cases with primary tumor of differentiated type, whereas peritoneal dissemination predominated when the primary lesion was undifferentiated. From the clinical standpoint, follow-up and recommendations to the patient should focus mainly on risk of peritoneal dissemination when adenocarcinoma of the stomach is of undifferentiated type, whereas metastases to distant organs should be taken into consideration if the malignancy is histologically differentiated.