Breast Cancer and various Prognostic Biomarkers for the diagnosis of the disease: A Review

Breast cancer starts when cells in the breast start to grow out of control. These cells often form a tumour that can
be seen on an x-ray. Cancer diagnosis is currently undergoing a paradigmatic shift with the incorporation of
molecular biomarkers as part of routine diagnostic panel. The molecular alterations range from those involving
the DNA, RNA, microRNAs (miRNAs) and proteins. Carcinoembryonic antigen (CEA) was the first tumour
marker to be used for diagnostic purposes of different human cancers (colorectal, pancreatic, breast, ovary, head
and neck, bladder, kidney, and prostate) and was found to be over expressed in serum of cancer patients as
compared to healthy individuals. The expression levels of miRNAs are highly tumour specific. This property of
the cancer cell is being exploited in cancer diagnosis for early and accurate cancer diagnosis. Over the last few
years, circulating noncoding molecules of RNA (miRNAs) are emerging as a useful class of cancer biomarkers
since they are found to be aberrantly expressed in different human cancers (tissues and serum) and are
characterized by unique levels of diagnostic specificity and sensitivity.