HER2 (human epidermal growth factor receptor 2) receptor is a membrane tyrosine kinase and when activated affects cell proliferation and survival. The HER2 oncogene is located on chromosome 17q12. HER2 amplification is the primary pathway of HER2 receptor overexpression and is a major driver of tumor development and progression in a subset of breast cancers. HER2 is amplified in about 15% to 20% of breast cancers. The overexpressed HER2 receptor is a valuable therapeutic target. The 2007 ASCO guidelines mandate that HER2 should be evaluated in every invasive breast cancer, either at the time of diagnosis or recurrence to guide therapy. Currently HER2 testing is carried out by several methods. It is crucial to standardize testing techniques to accurately assess HER2 status. The aim of this review on HER2 in breast cancer is to discuss the important aspects of HER2 biology, its significance in breast cancer, and the current standards for its detection.

Background: The androgen receptor (AR) has emerged as a potential therapeutic target for AR-positive triple-negative breast cancer (TNBC). However, conflicting reports regarding AR’s prognostic role in TNBC are putting its usefulness in question. Some studies conclude that AR positivity indicates a good prognosis in TNBC, whereas others suggest the opposite, and some show that AR status has no significant bearing on the patients’ prognosis. Methods: We evaluated the prognostic value of AR in resected primary tumors from TNBC patients from six international cohorts {US (n = 420), UK (n = 239), Norway (n = 104), Ireland (n = 222), Nigeria (n = 180), and India (n = 242); total n = 1407}. All TNBC samples were stained with the same anti-AR antibody using the same immunohistochemistry protocol, and samples with ≥1% of AR-positive nuclei were deemed AR-positive TNBCs. Results: AR status shows population-specific patterns of association with patients’ overall survival after controlling for age, grade, population, and chemotherapy. We found AR-positive status to be a marker of good prognosis in US and Nigerian cohorts, a marker of poor prognosis in Norway, Ireland and Indian cohorts, and neutral in UK cohort. Conclusion: AR status, on its own, is not a reliable prognostic marker. More research to investigate molecular subtype composition among the different cohorts is warranted.

Background: Diabetes mellitus is a major health problem worldwide with long-term micro- and macrovascular complications responsible for a majority of its morbidity and mortality. The development and progression of these complications relate strongly to glycemic control. Methods: We reviewed the literature extensively for studies that relate glycemic control to the development and progression of diabetic complications. We discuss the problems of standardizing glycohemoglobin measurements for monitoring diabetic therapy and also consider recently developed electrospray ionization mass spectrometry methods that have been considered as candidate reference methods for estimation of glycohemoglobin. Results: Several clinical trials and studies have clearly shown that improved glycemic control is strongly associated with decreased development and/or progression of complications in both type 1 and type 2 diabetes mellitus. Irrespective of the methods used for estimating glycohemoglobin, these results underline the importance of glycohemoglobin for guiding therapy of diabetes mellitus. Recently developed candidate reference methods promise to yield greatly improved standardization for the measurement of glycohemoglobin. Conclusions: Glycohemoglobin measurement remains the optimal indicator of glycemic control in diabetic patients, but translation of findings from clinical trials to clinical practice worldwide demands consistent values across all assays. To ensure that the important prognostic information still applies to all diabetic patients with the application of the reference method(s), the hemoglobin A1c values reported in the major clinical trials will have to be translated into statistically and computationally compatible values based on the new reference system(s).