Abstract
Blood sialyl-Tn antigen (STN) levels were studied in 137 patients with gastric cancer. High STN levels were observed in 20 cases (15%). STN levels were not correlated with those of CEA or CA19-9. STN levels were higher in advanced cancers, such as stage III and stage N. Serosal invasion was seen in 14 out of the 20 cases, and lymph node metastasis was detected in 17 cases. On histological examination, the gastric cancers with high STN levels were found to be undifferentiated cancers. On immunohistochemical analysis, STN-positive cancer cells were identified in every cases. The PCNA-indices of the cancer cells were than more 50% in high-STN gastric cancers. STN levels decreased after gastrectomy, but in several cases, they remained high, thereby indicating residual tumor after the operation. Recurrence occurred in several cases, and the STN level became high again. These results suggested that STN is correlated with the penetration and proliferation of cancer cells, etc, and the measurement of STN is useful in assessing the clinical stage and the recurrence of gastric cancers.
