Retrospective studies of gastric subserosal (ss) cancer--in comparison to pm- and se-cancers

The deepest gastric cancer invasion into the tela subserosa is expressed as the ss-cancer. Subserosal gastric cancers (ss) can be divided into 4 subtypes; ss alpha, ss beta, (ss gamma) and ss gamma, pathologically. These four subtypes were compared to cancerous invasion into the muscularis propria (pm-cancer) and cancerous invasion with serosal exposure (se-cancer). During the 10 years from 1979 to 1988, a total of 938 cases with gastric cancer were resected in the First Department of Surgery, Kurume University Hospital. Of these, 104 (11.1%) cases were ss-cancers, consisting of 28 (27%) cases of ss alpha, 33 (32%) cases of ss beta, 4 (3%) cases of (ss gamma) and 39 (38%) cases of ss gamma. Pm-cancers and ss-cancers were most frequently observed in Borrmann type 2, macroscopically, and in the differentiated type, histologically. On the other hand, se-cancers were frequently observed in Borrmann type 3 and in an undifferentiated type. Positive lymph node metastases were found in 49.1% of pm-cancers, in 50.0% of ss-cancers and in 79.9% of se-cancers (p < 0.01), with no statistical difference in the positive lymph node metastasis rates for the subdivisions of ss-cancer. In ss-cancer, however, there was a statistical difference in prognosis according to the tumor size, and according to the degree of subserosal infiltration. The 5-year survival rate was 82.3% for pm-cancer, 75.0% for ss-cancer and 34.7% for se-cancer (p < 0.01).