Detection of metastatic breast cancer by beta-hCG polymerase chain reaction.
Reverse transcriptase-polymerase chain reaction (RT-PCR) for detection of occult malignancies in breast cancer patients is evolving as a useful diagnostic tool. However, no reliable molecular mRNA markers are available. We developed an RT-PCR plus Southern blot assay using beta-hCG (beta-subunit of human chorionic gonadotropin) gene expression as a tumor marker for detection of breast malignancies metastatic to tumor-draining lymph nodes and blood. Breast carcinoma cell lines, primary breast malignancies and human placenta were used as positive controls for establishing the beta-hCG RT-PCR assay. Peripheral blood leukocytes (PBL) from normal volunteer donors, normal breast tissue and lymph nodes from cancer-free patients were used as negative controls. beta-hCG RT-PCR was used to assess tumor cell presence in PBL and tumor-draining axillary nodes from patients with AJCC stage I-IV breast cancer. The assay sensitivity and specificity were enhanced by restriction endonuclease digestion of an Sty I site of the RT-PCR cDNA product followed by Southern blot analysis. beta-hCG mRNA was expressed in all breast cancer cell lines and 80% of primary breast cancers; it was not expressed in negative controls. The assay reliably detected one cancer cell in > 10(7) PBL, with a sensitivity of 10(-5) microgram RNA. Eighty percent of PBL and 61% of tumor-draining axillary nodes from breast cancer patients expressed beta-hCG mRNA. The assay is a sensitive and specific method of identifying breast cancer cells in breast tissues, lymph nodes and blood.
Hoon
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Joyce Eisenberg Keefer Breast Cancer, John Wayne Cancer Institute, Saint John's Hospital and Health Center, Santa Monica, CA 90404, USA.
Sarantou
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Doi
F
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Chi
D D
DD
Kuo
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C
Conrad
A J
AJ
Schmid
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P
Turner
R
R
Guiliano
A
A
D014408:Biomarkers, Tumor / Q000032:analysis* / Q000096:biosynthesis; D015139:Blotting, Southern / Q000379:methods; D001940:Breast / Q000737:chemistry; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000032:analysis* / Q000096:biosynthesis; D005260:Female; D006801:Humans; D007962:Leukocytes / Q000378:metabolism; D008198:Lymph Nodes / Q000737:chemistry; D008207:Lymphatic Metastasis; D010920:Placenta / Q000737:chemistry; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000096:biosynthesis; D012334:RNA, Neoplasm / Q000032:analysis; D011974:Receptors, LH / Q000096:biosynthesis; D012680:Sensitivity and Specificity; D014407:Tumor Cells, Cultured
D014408:Biomarkers, Tumor; D018997:Chorionic Gonadotropin, beta Subunit, Human; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D011974:Receptors, LH