"Onic" tumor markers for breast cancer- a review

Breast cancer is a global health issue, and as the tumor burden increases, we need to come up with newer, better technologies which are convenient, cheap, rapid, sensitive with a high specificity. Technological advancements in the field of cancer biomarker has led to the development of techniques such as mass spectrometric analysis and microarray analysis in which genes, proteins and hundreds and thousands of metabolites can be identified with the emergence of genomics, proteomics and metabolomics. This research is focused on finding biomarkers for diagnosis, prognosis, staging, treatment response and targets for chemotherapy, generating a panel of markers which provide better clinical information compared to a single marker in the panel. This review briefly summarizes application of genomics and proteomics followed by key concepts and applications of metabolomics in breast cancer, with the conclusion that an integration of the three “OMIC” technologies may hold the key to future biomarker discovery.

Sources of Data/Study Selection: The information for this review was collected by searching the Google Scholar and PubMed database for English articles published in the period from 2002 to 2015. The search terms included “biomarkers in breast cancer” along with the following search terms: “genomics”, “proteomics”, “metabolomics”, “breast cancer”, “mass spectrometry”, “molecular markers” and “cancer biomarker”. We have endeavored to quote only the primary sources. Titles and abstracts of retrieved studies were assessed first followed by selection and retrieval of selected full text articles.

Abbreviations: ASCO – American Society of Clinical Oncology, ER – estrogen receptor, PgR – progesterone receptor, HER2 – human epidermal growth factor receptor 2,CA – cancer antigen, TAILORx – Trial Assigning Individualized Options for Treatment (Rx), MINDACT – Microarray InNode Negative Disease may Avoid ChemoTherapy using Mammaprint®, FDA – Federal Drug Authority, GC-TOF-MS – time of flight, LC/ESI-MS – electrospray ionization, PCho – phosphocholine, GPCho – glycerophosphocholine, Cdx-2 – caudal type homebox 2, KiSS1 – Kisspeptin 1, KAL1 – Kallman syndrome 1 sequence, NIST – National Institute of Standards and Technology, HMDB – Human metabolome database.