PLAC1 as a serum biomarker for breast cancer

• Published in: PloS one Vol. 13; no. 2; p. e0192106
• Main Authors: Yuan, Hongyan, Chen, Vincent, Boisvert, Marc, Isaacs, Claudine, Glazer, Robert I
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 12-02-2018; Public Library of Science (PLoS)
• Subjects: Adult; Aged; Aged, 80 and over; Antigens; Bioindicators; Biology and Life Sciences; Biomarkers; Body mass; Body mass index; Body size; Breast cancer; Breast Neoplasms - blood; Cancer; Care and treatment; Case-Control Studies; Development and progression; Diagnostic systems; Disease control; ErbB-2 protein; Estrogens; Family medical history; Female; Gene expression; Genetic aspects; Health aspects; Humans; Mammography; Medical diagnosis; Medical prognosis; Medicine and Health Sciences; Metastases; Middle Aged; Oncogenes; Oncology; Placenta; Preeclampsia; Pregnancy Proteins - blood; Proteins; Research and Analysis Methods; Serum levels; Surgery; Tumors; Womens health; Young Adult
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0192106

Placental-specific protein 1 (PLAC1) is an X-linked trophoblast gene that is re-expressed in several malignancies, including breast cancer, and is therefore a potential biomarker to follow disease onset and progression. Sera from 117 preoperative/pretreatment breast cancer patients and 51 control subjects, including those with fibrocystic disease, were analyzed for the presence of PLAC1 protein as well as its expression by IHC in tumor biopsies in a subset of subjects. Serum PLAC1 levels exceeded the mean plus one standard deviation (mean+SD) of the level in control subjects in 67% of subjects with ductal carcinoma in situ (DCIS), 67% with HER2+ tumors, 73% with triple-negative cancer and 73% with ER+/PR+ tumors. Greater sensitivity was achieved using the mean+2 SD of control PLAC1 serum values, where the false positive rate was 3% and was exceeded by 38%, 40%, 60% and 43% of subjects with DCIS, HER2+, TNBC and ER+/PR+/HER2- tumors. PLAC1 was detected in 97% of tumor biopsies, but did not correlate quantitatively with serum levels. There was no significant correlation of serum PLAC1 levels with race, age at diagnosis, body mass index (BMI) or the presence of metastatic disease. It remains to be determined whether PLAC1 serum levels can serve as a diagnostic biomarker for the presence or recurrence of disease post-surgery and/or therapy.