Comparison of two quantitative polymerase chain reaction methods for detecting HER2/neu amplification

Area of Science:

• Molecular Biology
• Oncology
• Clinical Diagnostics

Background:

• Accurate quantification of the HER2/neu gene is crucial for breast cancer diagnosis and treatment.
• Existing diagnostic methods require evaluation for clinical laboratory implementation.

Purpose of the Study:

• To evaluate two quantitative polymerase chain reaction (PCR) methods for HER2/neu gene quantification.
• To assess the clinical utility of real-time PCR and microdissection for HER2/neu amplification screening.

Main Methods:

• Developed and compared two quantitative PCR assays: real-time PCR and competitive PCR with melting curve analysis.
• Utilized sequence-specific hybridization probes for simultaneous detection of HER2/neu and beta-globin.
• Evaluated assays using cell lines, breast tumor samples, and compared with immunohistochemical (IHC) staining.

Main Results:

• Both PCR methods demonstrated high precision (CV < 3% within-run, < 6% between-run) and strong correlation (r = 0.974) in HER2/neu quantification.
• Real-time PCR and competitive PCR yielded comparable gene dose results for cell lines (SKBR3: 10-11, T47D: 2-2.2).
• Achieved 79% concordance between PCR and IHC; microdissection resolved discrepancies, confirming PCR accuracy.

Conclusions:

• Real-time quantitative PCR is a reliable and precise method for HER2/neu gene quantification.
• The combination of real-time PCR and microdissection provides a clinically useful approach for screening HER2/neu amplification.
• This method's ease of use and broad dynamic range facilitate efficient HER2/neu amplification screening in clinical settings.