Evaluation of serum HER2 extracellular domain in early breast cancer patients: correlation with clinicopathological parameters and survival.
BACKGROUND
We explored the correlation between serum human epidermal growth factor receptor-2 (HER2) extracellular domain (ECD) and tissue HER2 status, their relationship with clinicopathological parameters and their impact on disease-free survival (DFS) and overall survival in early breast cancer patients.


METHODS
This prospective trial included patients with stage I-III breast cancer. Serum HER2 ECD levels were measured by two enzyme-linked immunosorbent assays before surgical treatment. Tissue HER2 status was analyzed by immunohistochemistry (IHC) in all tumors; FISH assay was utilized in HER2 2+ tumors by IHC.


RESULTS
From May 2000 to July 2005, 256 consecutive stage I-III breast cancer patients were included in this study. High serum HER2 ECD levels (>or=15 ng/ml) were reported in 23 patients (9.0%) and HER2-positive status in tumor tissue was observed in 42 patients (16.4%) with a concordance of 87.1%. High HER2 ECD levels were significantly associated with high histological grade (P = 0.003), stage III (P = 0.008), lymph node involvement (P = 0.035) and negativity of both estrogen (P = 0.016) and progesterone (P = 0.007) receptors. At multivariate analysis, high serum HER2 ECD levels were a significant independent prognostic factor of worse DFS (P = 0.009).


CONCLUSIONS
A statistically significant association was observed between high serum HER2 ECD levels and worse DFS in early breast cancer patients.
Ludovini
V
V
Medical Oncology Division, Azienda Ospedaliera of Perugia, Perugia, Italy. oncolab@hotmail.com
Gori
S
S
Colozza
M
M
Pistola
L
L
Rulli
E
E
Floriani
I
I
Pacifico
E
E
Tofanetti
F R
FR
Sidoni
A
A
Basurto
C
C
Rulli
A
A
Crinò
L
L
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000097:blood* / Q000737:chemistry / Q000401:mortality / Q000473:pathology / Q000628:therapy; D002277:Carcinoma / Q000097:blood* / Q000737:chemistry / Q000401:mortality / Q000473:pathology / Q000628:therapy; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D018734:Genes, erbB-2; D006801:Humans; D008408:Mastectomy; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000097:blood*; D009376:Neoplasms, Hormone-Dependent / Q000097:blood / Q000737:chemistry / Q000401:mortality / Q000473:pathology / Q000628:therapy; D011379:Prognosis; D011446:Prospective Studies; D017434:Protein Structure, Tertiary; D018714:Radiotherapy, Adjuvant; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000097:blood*; D011960:Receptors, Estrogen / Q000032:analysis; D011980:Receptors, Progesterone / Q000032:analysis; D016019:Survival Analysis
D009363:Neoplasm Proteins; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone