Several studies have demonstrated that
tumor cell-derived
RNA is presented in the plasma from
breast cancer patients. However, no studies have focused on the detection of plasma erbB2
mRNA in
breast cancer. In this study the expression of erbB2
mRNA in the plasma was analyzed in 106
breast cancer patients and 50 healthy subjects by using a nested RT-PCR strategy, and the
circulating tumor cells were also detected by using a nested RT-PCR for detection of mammaglobin transcripts in the peripheral blood. Plasma erbB2
mRNA was detectable in 46 (43.3%)
breast cancer patients, whereas only 5 normal subjects (10%) were positive in the control group (p = 0.001). The presence of erbB2
mRNA in the plasma was not associated with menopausal status, erbB2 expression in primary
tumor tissues,
tumor size, histological grade, Ki-67 expression or lymph node involvement, but it exhibited a trend for correlation with increasing
tumor stages (p = 0.085), and the presence of erbB2
mRNA in the plasma was significantly associated with negative
estrogen receptor (ER) and
progesterone receptor (PR) status of the primary
tumors (p = 0.031 and 0.026, respectively). Furthermore, in a small subset of 36
breast cancer patients we found the presence of plasma erbB2
mRNA was significantly correlated with the occurrence of
circulating tumor cells (p = 0.01). Our study suggests that
breast cancer patients with the presence of erbB2
mRNA in the plasma may have a high
malignancy or an aggressive phenotype, and frequently detecting plasma erbB2
mRNA may provide a novel approach for monitoring
breast cancer progression or response to treatment.