Small breast epithelial mucin (SBEM), human hypoxanthine-guanine phosphoribosyltransferase (HPRTh), and murine hypoxanthine-guanine phosphoribosyltransferase (HPRTm) expression were analyzed by real-time polymerase chain reaction to detect multifocal metastases in right/left renal capsule, liver, spleen, and pancreas.
The marker gene panel selected, designed to detect the mRNA of CK19, p1B, EGP2 and SBEM, was subsequently applied to detect metastases in 70 SNs that were free ofmetastases as determined by standard histological evaluation.
In a subset of 20 primary breast tumors and their matched axillary lymph nodes, a high concordance (Fisher's exact test, P < 0.001) was seen between PCR detection of SBEM mRNA in lymph node tissue and their histopathological status, indicating that SBEM mRNA expression is conserved in nodal metastasis.