Abstract
Simultaneous multiple gastric cancers were seen in 58 (5.6%) of 1039 stomach cancer patients. Recently the incidence of multiple early gastric carcinomas has been increasing and its incidence is 8.6% of early gastric cancers. The characteristic features of multiple early gastric cancers (MEGC) are the elevated type (35.2%) morphologically and differentiated type (68.6%) microscopically. Most (81.8%) of the multiple early gastric carcinomas were treated by distal gastrectomy. Lymphatic metastasis was found in 9.1% and its rate was roughly similar to that for single early gastric cancers (SEGC; 11.1%). The incidence of gastric cancers found at the remnant mucosa within 5 years of distal gastrectomy was 3.6% for MEGC, comparable to that for SEGC (2.2%). Cytofluorometry, DNA ploidy analysis for the patients without recurrence for more than 10 years showed that 93.8% of the lesions were of the diploid pattern, without a significant difference in the malignant potential based on cell proliferative activity among both the lesions and the cases. On the other hand, the lesions in the patient who died of recurrence showed a variety of polyploid patterns with increased S-G2 cells. These ploidy patterns were very similar to those of advanced gastric cancers. These results clearly indicated that the malignant potential based on cell population kinetics was increasing during cancer growth. The present study suggests that the growth characteristics in relation to the prognosis of SEGC can also be applied to MEGC.
