Estrogen-Receptor, Progesterone-Receptor and HER2 Status Determination in Invasive Breast Cancer. Concordance between Immuno-Histochemistry and MapQuant™ Microarray Based Assay

Abstract

BackgroundHormone receptor status and HER2 status are of critical interest in determining the prognosis of breast cancer patients. Their status is routinely assessed by immunohistochemistry (IHC). However, it is subject to intra-laboratory and inter-laboratory variability. The aim of our study was to compare the estrogen receptor, progesterone receptor and HER2 status as determined by the MapQuant™ test to the routine immuno-histochemical tests in early stage invasive breast cancer in a large comprehensive cancer center.Patients and MethodsWe retrospectively studied 163 invasive early-stage breast carcinoma with standard IHC status. The genomic status was determined using the MapQuant™ test providing the genomic grade index.ResultsWe found only 4 tumours out of 161 (2.5%) with discrepant IHC and genomic results concerning ER status. The concordance rate between the two methods was 97.5% and the Cohen’s Kappa coefficient was 0.89.Comparison between the MapQuant™ PR status and the PR IHC status gave more discrepancies. The concordance rate between the two methods was 91.4% and the Cohen’s Kappa coefficient was 0.74.The HER2 MapQuant™ test was classified as « undetermined » in 2 out of 163 cases (1.2%). One HER2 IHC-negative tumour was found positive with a high HER2 MapQuant™ genomic score. The concordance rate between the two methods was 99.3% and the Cohen’s Kappa coefficient was 0.86.ConclusionOur results show that the MapQuant™ assay, based on mRNA expression assay, provides an objective and quantitative assessment of Estrogen receptor, Progesterone receptor and HER2 status in invasive breast cancer.

Immunohistochemical Expression of BRCA1 Protein, ER, PR and Her2/neu in Breast Cancer: A Clinicopathological Study

“…Similarly, Tung et al, reported in 2010 that Patients younger than 50 years diagnosed with BC were significantly more likely to have an ER negative cancer compared with older aged patients (Tung et al, 2010). It is important to mention that considerable percentages of negative ER may be "false negative" due to some technical factors related to inappropriate tissue fixation, antigen retrieval or staining a necrotic areas (Mouttet et al, 2016;Nadji et al, 2005). Moreover, the lack of standardised measurements of grade and ER increases the errors in the results (Foulkes et al, 2004).…”

“…Moreover, the lack of standardised measurements of grade and ER increases the errors in the results (Foulkes et al, 2004). Furthermore, the cut off point for negativity of ER/ PR in most studies is calculated as immunostained active cells<10% whereas the new guidelines consider negative ER/PR as <1% (Mouttet et al, 2016).…”

Correlation between 18F-FDG Positron-Emission Tomography 18F-FDG Uptake Levels at Diagnosis and Histopathologic and Immunohistochemical Factors in Patients with Breast Cancer

“…Estrogen and progesterone receptors hold a crucial place in determining prognosis for patients with breast cancer and establishing whether they would benefit from hormonal therapy. HER2 status is an important predictive factor that determines whether the patients can start goal-directed therapy (trastuzumab) (34). Luminal A tumors (positive ER and PR, negative HER2, Ki-67 <1%) is the subtype with the best prognosis, triple-negative tumors show more biologically aggressive behavior (30,35).…”

Clinical implications of tumor necrosis factor receptor 2 in breast cancer

“…Therefore, the association of all the adjuvant therapies with prognosis was not investigated. BC is a complicated disease and its prognosis may be effected by different factors, including age, menopausal status, clinical stage, pathological grade and receptors on the tumor cell surface (25)(26)(27). Tumor cells at an advanced stage usually possess higher malignant behaviors, including proliferation, migration, invasion and drug resistance, and lose surgery opportunity, resulting in poor prognosis (28,29).…”