EFFICACY OF REVERSE TRANSCRIPTASE-POLYMERASE CHAIN-REACTION SCREENINGFOR MICROMETASTIC DISEASE IN AXILLARY LYMPH-NODES OF BREAST-CANCER PATIENTS

Pathologic examination of axillary lymph nodes (ALNs) may miss microme tastases in 30 per cent of breast cancer patients. We have developed a multimarker reverse transcriptase-polymerase chain reaction (RT-PCR)- based screening method that detects histopathologically positive ALNs with a 5 per cent false-negative rate. The purpose of this study was t o compare this RT-PCR methodology with histopathology with regard to s ensitivity and cost. Pathologically negative ALNs from 35 breast cance r patients were re-evaluated by a single pathologist in a blinded fash ion using serial sectioning with immunohistochemical staining. Histopa thologic results were then compared with those of RT-PCR. Cost analysi s was performed based on standard charges for these methods. RT-PCR id entified micrometastases in 14 of 35 pathologically negative nodes. Se rial sectioning and immunohistochemical staining identified micrometas tases in two cases, with RT-PCR positive for one of these. The charge per specimen for performing routine histopathologic examination was $3 80, serial sectioning and immunohistochemical staining $787, and RT-PC R $125. RT-PCR appears to be more sensitive at detecting ALN micrometa stasis than histopathologic examination even with serial sectioning an d immunohistochemical staining. If micrometastatic breast cancer detec ted by RT-PCR proves to be clinically relevant, it could be a more eff ective screening methodology with significant cost savings as compared to currently available pathologic examinations.