M. Sakaguchi et al., Development of a sensitive, specific reverse transcriptase polymerase chain reaction-based assay for epithelial tumour cells in effusions, BR J CANC, 79(3-4), 1999, pp. 416-422
We developed a sensitive and specific method for the detection of epithelia
l cancer cells in effusions with a two-stage molecular-based assay which co
mbined enrichment for cancer cells by immunomagnetic bead selection and rev
erse transcriptase polymerase chain reaction (RT-PCR) detection of epitheli
al glycoprotein 2 (EGP-2) RNA. Preliminary experiments indicated that immun
obead selection was essential to avoid occasional false-positive RT-PCR res
ults, and this method detected ten breast cancer cells electively added to
10(7) cytologically negative effusion cells. We studied 110 cases of pleura
l (n = 68) and peritoneal (n = 42) effusions (30 from patients with known c
arcinoma and 80 from those without known carcinoma), and the results were c
ompared with cytological findings. Of 18 effusions that were cytologically
positive or suspicious for malignant cells, 17 (94%) were positive far EGP-
2 RNA (the one negative sample was from a patient who recently received com
bination chemotherapy). Of 92 cytologically negative samples, 11 (12%) were
positive for EGP-2, including six patients with a history of previous or c
urrent carcinoma. Our method appears to be highly specific and increases th
e sensitivity of detection of malignant cells; it may be a useful adjunct t
o routine cytopathological examination.