ABSTRACT:
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.