NASBA: a novel approach to assess hormonal receptors and ERBB2 status in breast cancer

Comparison of epidemiological features, clinicopathological features, and treatments between premenopausal and postmenopausal female breast cancer patients in western China: a retrospective multicenter study of 15,389 female patients

Premenopausal and postmenopausal breast cancers are considered different types. Thus, this study aimed to explore differences in risk factors, epidemiological features, clinicopathological features, and treatment modes of premenopausal breast cancer compared to postmenopausal patients in western China. This was a hospital-based, retrospective, multicenter epidemiological study of patients with breast cancer. Using the Western China Clinical Cooperation Group database, we obtained the records of 15,389 female breast cancers between January 2010 and April 2017. These patients were divided into premenopausal and postmenopausal groups, and their risk factors, epidemiological feature, clinicopathological features, and treatment modes were compared. Chi-square tests, t-test, and the multivariate logistic regression analysis were applied for statistical analysis. A total of 8395 patients were categorized as premenopausal, and 6994 patients were categorized as postmenopausal. Their risk factors, epidemiological features, clinicopathological features, and treatment modes were compared. Premenopausal patients with breast cancer had a greater tumor diameter at diagnosis (P = 0.008); higher rates of estrogen receptor (ER) expression (P < 0.0001), progesterone receptor (PR) expression (P < 0.0001), negative human epidermal growth factor receptor 2 (HER2) expression (P = 0.015), and negative P53 expression (P < 0.0001); and higher proportions of receiving breast-conserving surgery and breast reconstruction (P < 0.0001), chemotherapy (P < 0.0001), radiotherapy (P < 0.0001), and endocrine therapy (P < 0.0001). The ethnicity, age at menarche, marital status, number of pregnancies, and number of births were the risk factors for age at diagnosis of breast cancer before or after menopause in western China. We found that the fall in the fertility rate, early menarche age, married, and less breastfeeding might have increased the possibility of premenopausal breast cancer. Significant differences exist in the tumor size, hormone receptor state, HER2 expression, epidemiological features, and treatment modes between premenopausal and postmenopausal female breast cancer patients in western China. Its further implementation requires prospective clinical testing.

Integrated microfluidic array plate (iMAP) for cellular and molecular analysis

Just as the Petri dish has been invaluable to the evolution of biomedical science in the last 100 years, microfluidic cell assay platforms have the potential to change significantly the way modern biology and clinical science are performed. However, an evolutionary process of creating an efficient microfluidic array for many different bioassays is necessary. Specifically for a complete view of a cell response it is essential to incorporate cytotoxic, protein and gene analysis on a single system. Here we present a novel cellular and molecular analysis platform, which allows access to gene expression, protein immunoassay, and cytotoxicity information in parallel. It is realized by an integrated microfluidic array plate (iMAP). The iMAP enables sample processing of cells, perfusion based cell culture, effective perturbation of biologic molecules or drugs, and simultaneous, real-time optical analysis for different bioassays. The key features of the iMAP design are the interface of on-board gravity driven flow, the open access input fluid exchange and the highly efficient sedimentation based cell capture mechanism (∼100% capture rates). The operation of the device is straightforward (tube and pump free) and capable of handling dilute samples (5-cells per experiment), low reagent volumes (50 nL per reaction), and performing single cell protein and gene expression measurements. We believe that the unique low cell number and triple analysis capabilities of the iMAP platform can enable novel dynamic studies of scarce cells.

A single-tube quantitative assay for mRNA levels of hormonal and growth factor receptors in breast cancer specimens

Knowledge of estrogen receptor (ER) and progesterone receptor (PR) status has been critical in the evolution of modern targeted therapy of breast cancer and remains essential for making informed therapeutic decisions. Recently, growth factor receptor HER2/neu (ERBB2) status has made it possible to provide another form of targeted therapy linked to the overexpression of this protein. Presently, pathologists determine the receptor status in formalin-fixed, paraffin-embedded sections using subjective, semiquantitative immunohistochemistry (IHC) assays and quantitative fluorescence in situ hybridization for HER2. We developed a single-tube multiplex TaqMan (mERPR+HER2) assay to quantitate mRNA levels of ER, PR, HER2, and two housekeeping genes for breast cancer formalin-fixed, paraffin-embedded sections. Using data from the discovery sample sets, we evaluated IHC-status-dependent cutoff-point and IHC-status-independent clustering methods for the classification of receptor status and then validated these results with independent sample sets. Compared with IHC-status, the accuracies of the mERPR+HER2 assay with the cutoff-point classification method were 0.98 (95% CI: 0.97-1.00), 0.92 (95% CI: 0.88-0.95), and 0.97 (95% CI: 0.95-0.99) for ER, PR, and HER2, respectively, for the validation sets. Furthermore, the areas under the receiver operating-characteristic curves were 0.997 (95% CI: 0.994-1.000), 0.967 (95% CI: 0.949-0.985), and 0.968 (95% CI: 0.915-1.000) for ER, PR, and HER2, respectively. This multiplex assay provides a sensitive and reliable method to quantitate hormonal and growth factor receptors.

Correction for chromosome-17 is critical for the determination of true Her-2/neu gene amplification status in breast cancer

PURPOSE

Trastuzumab is the cornerstone for treatment of women with HER2-overexpressing breast cancer, both in the adjuvant and in the metastatic settings. The accurate assessment of HER2 is, therefore, critical to identifying patients who may benefit from trastuzumab-based therapy. This project aimed to determine the optimal scoring method for fluorescence in situ hybridization (FISH) assay.

METHODS

FISH assay was done on 893 samples of breast cancer. Three scoring methods were evaluated: Her2/CEP17> or =2, Her2>4, or Her2>6. Protein and gene expression were evaluated by immunohistochemistry (n = 584) and mRNA/assay/nucleic acid sequence-based amplification (NASBA; n = 90).

RESULTS

Samples were divided into five groups based on FISH results: disomic amplified and nonamplified, polysomic amplified, nonamplified, and discordant (10.8% of cases, mostly positive with Her2>4 scoring, but negative with the others). Her2/CEP17> or =2 and Her2>6 scoring methods showed the best association (a) with regard to FISH scoring (kappa = 0.906, P < 10(-6)) and (b) between FISH and immunohistochemistry (3+ as positive; kappa > 0.650, P < 10(-6)) or NASBA (kappa > 0.536, P < 10(-6)). Polysomy had an effect on Her2 copy number (P < 10(-6)), but had no effect on protein and mRNA content. Therefore, within the discordant subgroup, for which additive Her-2 gene copies are due to high polysomy, protein and mRNA levels were similar to those of the nonamplified samples. For this subgroup, the best concordance between FISH/immunohistochemistry/NASBA was observed with the Her2/CEP17 ratio and Her-2>6 scoring (68% and 58% perfect matches, respectively). No perfect matches were observed using the Her2>4 scoring method.

CONCLUSION

Correction for chromosome-17 is the method of choice for clinical practice; Her-2>6, but not Her-2>4, could be used as an alternative.