Evaluation of the Quantitative Analytical Methods Real-Time PCR for HER-2 Gene Quantification and ELISA of Serum HER-2 Protein and Comparison with Fluorescence in Situ Hybridization and Immunohistochemistry for Determining HER-2 Status in Breast Cancer Patients

Abstract

Background: HER-2 status is generally determined by immunohistochemistry (IHC) or fluorescence in situ hybridization (FISH). Both methods are only semiquantitative, require a tumor sample, and can be difficult to reproduce. We compared these methods with 2 quantitative approaches, one measuring HER-2 gene copy number in tissue by real-time quantitative PCR (qPCR), and the other measuring shed HER-2 protein in serum by ELISA in patients with metastatic disease. Methods: We analyzed 52 cases of metastatic breast cancer for which both serum collected at the diagnosis of metastasis and stored primary breast tumor specimens were available. The within-and between-run imprecision of real-time qPCR and ELISA were evaluated according to Clinical and Laboratory Standards Institute (formerly known as NCCLS) recommendations. Concordance among the 4 methods was assessed by calculating the statistic and its 95% confidence interval (95% CI).

Relationship between erb-B2 mRNA Expression in Blood and Tissue of Invasive Ductal Carcinoma Breast Cancer Patients and Clinicopathological Characteristics of the Tumors

“…This discrepancy between RT-PCR and immunohistochemical results can be justified by transcriptional or post-transcriptional activation. PCR false negative result was also shown between quantitative PCR and immunohistochemical methods (Königshoff et al, 2003;Tse et al, 2005). In the other hand, immunohistochemical negative blood sample (26%) and immunohistochemical negative tissue sample (48%) was identified by RT-PCR, in our study.…”

“…This study showed no correlation between erb-B2 mRNA expression in peripheral blood and/or tumor tissue and other prognosis factors. In this study, there is not significant correlation between the expression of erb-B2 and tumor size or lymph node in BC patients as mentioned in previous studies (Tse et al, 2005;Youssef et al, 2013).…”

Accurate breast cancer diagnosis through real-time PCR her-2 gene quantification using immunohistochemically-identified biopsies

“…Discrepancies of 20-40% from samples evaluated as IHC 2+ with respect to results obtained by using FISH or qPCR techniques have been reported (11,(13)(14)(15)(16)(17). In this study, from fifteen biopsies evaluated as IHC 2+, four (ID 3, 7, 65 and 77) were identified with a <2.0 qPCR ratio, showing non-amplification differences with respect to the negative control (Table I).…”

Predicting Tissue HER2 Status Using Serum HER2 Levels in Patients with Metastatic Breast Cancer

“…This leads to increased serum HER2 ECD concentrations in ϳ30%-40% of patients with metastatic breast cancer and serves as a marker for prognosis and resistance to hormone and alkylating therapy (12)(13)(14). Serum HER2 ECD concentration correlates with tissue HER2 status (by IHC or FISH) (15 ), and the possibility of using it as an alternative to tissue analysis has recently been examined (16 ). In this study, we investigated that possibility further in view of the discordant positive rates between tissue HER2 and serum HER2 in metastatic breast cancer, and we suggest a method that optimizes predictive power of serum HER2 ECD concentration.…”