Circulating tumor cells in peripheral blood caused by surgical manipulation of non-small-cell lung cancer: pilot study using an immunocytology method

Objective. Reverse transcriptase-polymerase chain reaction assay results have indicated that tumor cells sometimes appear during surgery for primary non-small-cell lung cancer. In this study, we attempted to determine whether cancer cells can be detected during and after surgery using an immunocytology method. Methods. Nine patients undergoing a lobectomy for non-small-cell lung cancer were studied. The presence of circulating tumor cells was determined by the detection of magnified EpCAM antibodies. The criteria used to identify circulating tumor cells were a round-to-oval morphology with a visible nucleus (4'-6'-diamidino-2-phenylindole (DAPI)-positive), which were positive for cytokeratin and negative for CD45. Results. One patient showed evidence of circulating tumor cells at thoracotomy, and 3 patients did so after surgery. Ten days after the operation, the circulating tumor cells had disappeared in all these cases. The median follow-up period was 14 months, and there was no cancer recurrence in any of the patients. Conclusion. Using this technique, tumor cells were detected in the peripheral blood of patients before and after lobectomy procedures. It could be argued that this method can provide useful information about patients undergoing lung cancer treatment.