Current and emerging biomarkers in breast cancer: prognosis and prediction

Abstract

Breast cancer treatment has experienced several changes in the past decades due to the discovery of specific prognostic and predictive biomarkers that enable the application of more individualized therapies to different molecular subgroups. These subgroups show specific differences regarding biological clinical behavior. In addition to the classical clinical prognostic factors of breast cancer, established molecular biomarkers such as estrogen receptor and progesterone receptor have played a significant role in the selection of patients benefiting from endocrine therapy for many years. More recently, the human epidermal growth factor receptor 2 (HER2) has been validated to be not only a prognostic factor, but also a predictor of response to HER2 targeting therapy. The shift toward an earlier diagnosis of breast cancer due to improved imaging methods and screening programs highlights the need for new factors and combinations of biomarkers to quantify the residual risk of patients and to indicate the potential value of additional treatment strategies. The marker of proliferation Ki67 has recently emerged as an important marker due to several applications in neoadjuvant therapy in addition to its moderate prognostic value. With the introduction of high-throughput technologies, numerous multigene signatures have been identified that aim to outperform traditional markers: current prospective clinical trials are seeking evidence for their definitive role in breast cancer. There exist many more factors and approaches that have the potential to become relevant in the near future including the detection of single disseminating and circulating tumor cells in blood and bone marrow as well as of circulating cell-free DNA and microRNA. Careful randomized prospective testing and comparison with existing established factors will be required to select those emerging markers that offer substantial cost-effective benefit and thereby justify their routine use for breast cancer therapy decision-making.

A Case-Matched Gender Comparison Transcriptomic Screen Identifies eIF4E and eIF5 as Potential Prognostic Markers in Male Breast Cancer

“…However, there are multiple examples of biomarkers being expressed in different, or even the same type, of breast cancer, but which are only of clinical use when expressed above a certain threshold (reviewed in ref. 34). Interestingly, a search on Oncomine showed that eIF4E and eIF5 were not only increased in tumor versus normal breast and lung cancers, but that eIF4E and eIF5 expression was proportionately higher in MBC when genders were compared, substantiating our findings.…”

Comparative study of Her-2, p53, Ki-67 expression and clinicopathological characteristics of breast cancer in a cohort of northern China female patients

“…32,33 The association between Her-2 and Ki-67 in breast cancer patients 5,6,31,34,35 makes Ki-67 an emerging biomarker for breast cancer. 36 This study retrospectively compared 160 cases of Her-2 overexpressing breast cancer patients with 100 cases of Her-2 negative patients in terms of clinicopathological characteristics and the expression of p53 and Ki-67, and further uncovered the connection among Her-2, p53 and Ki-67.…”

The History and Physical in Cancer Care: A Primer for the Oncology Advanced Practitioner

“…However, treatment decisions extend beyond these traditional parameters. Considerations also include the specific molecular or genetic markers necessary to determine both prognostic (the natural history of the tumor) and predictive (effective therapies) information (Weigel & Dowsett, 2010).…”