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