The authors discuss a topic rarely covered in the current surgical literature: quantitation of shed tumor cells during the course of oncologic operations. The subject is reminiscent of past discussions of the "no-touch" technique or of suture line implantation during resection of colorectal cancers. The findings are relevant today as scientists seek to understand the intricate mechanisms of tumor metastasis and tumor-host interactions.
Tumor cells were isolated from blood in the operative field by density gradient centrifugation in most (57 of 61) of the diverse group of patients undergoing oncologic operations in this study; this finding may be explained by tumor manipulation and the existence of malignant cells in adjacent cut vessels and lymphatics. The methods used are sophisticated, eg, the ability to detect two to four of 10 tumor cells (by their content of cytokeratin and nucleolar organizer regions) in 500 mL of blood. The authors also injected cell