Molecular Prognosis of Carcinomas In Situ
methods for identifying and studying circulating tumor cells (CTC) have been problematic, as they require complex
cell isolation procedures, comprising many
technical challenges which limit utility in clinical medicine.
BC200 RNA is a small non-protein-coding RNA normally restricted
to neuronal expression. The dramatic
exception to this is that BC200 is
detected in a number of tumors, such as invasive carcinomas of the
breast, but not in normal breast tissue, or in benign tumors such as
fibroadenomas. Data from the Tiedge laboratory
at SUNY Downstate, using invasive breast
cancer patients, normal controls, and treated breast cancer
patients, indicate that BC200 RNA is a
high-fidelity marker of circulating tumor cells.
The data indicate a remarkable specificity for this marker in
tumor-bearing patients, whereas only
background levels of BC200 RNA are detected in
normal subjects. The technology employs the quantitative polymerase
chain reaction (qPCR), capable of
detecting as few as several cells in a blood
sample. This simple CTC assay is performed routinely on whole blood
and is functional with any RT-PCR
diagnostic platform in use.