Identification of mammaglobin as a novel serum marker for breast cancer.
OBJECTIVE
Early detection of breast cancer has implications for the management and treatment of patients with this disease. Currently, there exist no highly sensitive and specific serologic biomarkers for detection of breast cancer. Mammaglobin is predicted to be a secreted protein, and expression of this gene seems to be highly specific in breast cancer. The present studies were undertaken to develop the mammaglobin protein as a serum biomarker for detection of breast cancer.


METHODS
We characterized the mammaglobin protein as a secreted, 14- to 21-kDa species, which is likely post-translationally processed based on its predicted 7-kDa size. Immunostaining for mammaglobin was conducted. An ELISA was developed for the detection of the mammaglobin protein in serum, and levels were compared between women with and without breast cancer. A receiver operating characteristic curve was used to show sensitivity and specificity for cut points on the continuous mammaglobin scale.


RESULTS
The protein was detectable by immunostaining in 72% of breast tumors and not in other tumor types. The ELISA was highly sensitive and specific for detection of mammaglobin protein in tissue culture fluids of breast cancer cells and sera of breast cancer patients. The ELISA differentiated healthy women from those with breast cancer with accurate, repeatable results across time and under varying storage conditions.


CONCLUSIONS
Our results indicate that mammaglobin, as measured by the ELISA, holds significant promise for breast cancer screening with the realistic potential to impact management of this disease.
Bernstein
Jonine L
JL
Departments of Community and Preventive Medicine, Mount Sinai School of Medicine, New York, NY, USA. bernstej@mskcc.org
Godbold
James H
JH
Raptis
George
G
Watson
Mark A
MA
Levinson
Brooke
B
Aaronson
Stuart A
SA
Fleming
Timothy P
TP
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D001943:Breast Neoplasms / Q000097:blood* / Q000175:diagnosis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D060785:Mammaglobin A; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000097:blood*; D012680:Sensitivity and Specificity; D014598:Uteroglobin / Q000097:blood*
D014408:Biomarkers, Tumor; D060785:Mammaglobin A; D009363:Neoplasm Proteins; C556448:SCGB2A2 protein, human; D014598:Uteroglobin