The effects of preoperative chemotherapy on isolated tumour cells in the blood and bone marrow of gastric cancer patients

Recent studies in breast cancer suggest that monitoring the isolated tumour cells (ITC) may be used as a surrogate marker to evaluate the efficacy of systemic chemotherapy. In the present study, we have investigated the effects of preoperative chemotherapy on ITC in the blood and bone marrow of patients with potentially resectable gastric cancer. After sorting out the CD45-positive cells, the presence of ITC defined as cytokeratin-positive cells was examined before and after preoperative chemotherapy. The patients received two courses of preoperative chemotherapy with cisplatin (100 mg m−2, day 1) and 5-fluorouracil (1000 mg m−2, days 1–5), administered every 28 days. Fourteen of 32 (44%) patients initially diagnosed with ITC in blood and/or bone marrow were found to be negative (responders) after preoperative chemotherapy (P<0.01). The incidence of ITC in bone marrow was also significantly (P<0.01) reduced from 97 (31 of 32) to 53% (17 of 32). The difference between patients positive for ITC in the blood before (n=7, 22%) and after (n=5, 16%) chemotherapy was statistically insignificant. The overall 3-year survival rates were 32 and 49% in the responders and non-responders, respectively (P=0.683). These data indicate that preoperative chemotherapy can reduce the incidence of ITC in patients with gastric cancer

Expression of nonspecific cross-reacting antigen species in myeloid leukemic patients and healthy subjects

The reactivity of two monoclonal antibodies recognizing NCA-95 and NCA-55 (MAb 47 and MAb 192, respectively) with a polyclonal anti-NCA serum in myeloid leukemic cells isolated by density gradient centrifugation was compared using an immunofluorescence test (IF). It was observed that the blood myeloid cells in 78.8% of the patients with different types of myelocytic leukemias and all granulocytes of 15 normal donors showed similar expression of the NCA species studied. The leukocytes of the remaining patients did not synthesize the NCA-95 species regardless of the maturation stage of the cells studied. In two patients, synthesis of this NCA form was limited to the fractions containing myelocytes and metamyelocytes. We have found that all anti-NCA antibodies studied recognized different antigenic epitopes in a myeloid cell series. A relationship between the patient's survival and the proportion of NCA-containing cells was also observed