Detection of intraoperative tumor cell dissemination in patients with breast cancer by use of reverse transcription and polymerase chain reaction.

BACKGROUND: Animal studies have shown that malignant cells are shed into the blood stream during surgical resection of a primary tumor and that this may enhance the development of metastases. The evidence for tumor cell dissemination during surgical manipulation of human cancer is unclear. We have applied the technique of reverse transcription and polymerase chain reaction to detect circulating tumor cells in peripheral venous blood of patients with breast cancer perioperatively.
METHODS: To target breast-specific gene transcription complementary DNA was prepared by reverse transcription of blood messenger RNA with oligonucleotide primers unique to CK18 and DF3 antigens. Preliminary assessment of specificity showed that the DF3 antigen was more suitable than CK18 for the purpose of this study. Assessment of sensitivity showed that as few as 10 tumor cells per 5 ml blood could be identified by this method. Peripheral blood samples were obtained by venepuncture from patients before, during, and 24 hours after breast surgery (nine malignant and three benign).
RESULTS: In the group of patients with malignant disease, tumor cells were detected in one patient before operation and four patients during operation. No tumor cells were detected in the postoperative samples nor in any of the samples of patients with benign disease.
CONCLUSIONS: These findings suggest that tumor manipulation during operation encourages tumor cell dissemination.