CTCs detection from intraoperative salvaged blood in RCC–IVC thrombus patients by negative enrichment and iFISH identification: a preliminary study

BACKGROUND: Intra-operative cell salvage (IOCS) and leukocyte-depleted filter (LDF) are widely used and effective in saving blood. However, the safety issue concerning reinfusion of IOCS–LDF processed blood to renal cell carcinoma (RCC) patients with inferior vena cava (IVC) thrombus were inconclusive for fear of increased risk of cancer metastases. This study intends to analyze the circulating tumor cell (CTC) eliminating effect of IOCS–LDF in 5 RCC–IVC thrombus patients. METHODS: A novel strategy integrating negative enrichment by immunomagnetic beads and immunostaining-fluorescence in situ hybridization with probes identifying aneuploid of 8 and/or 7 were used to detect CTCs from salvages blood. Blood samples were collected from 4 stages in each patient. RESULTS: Of the 5 RCC patients, the number of CTCs decreased (from 3, 4, 10, 7, 3, respectively, to all zero) after IOCS–LDF treatment. The triploid of chromosome 7 and/or chromosome 8 were most common karyotype for RCC patients with IVC thrombus. Tetraploid of chromosome 8 occurred in only one sample and no polypoid (number of chromosome > 4) were found. CONCLUSION: IOCS–LDF might be a promising way of reducing of allogeneic product transfusion based on current preliminary outcome. More convincing conclusions are to be drawn with enlarged sample size and long-term follow-up for patients prognosis.