Biomarkers in oncology: overview

Published on January 6, 2009 Reviewed on January 19, 2016   27 min

A selection of talks on Clinical Practice

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Hello. My name is Professor Joe Duffy. I am based at St Vincent's University Hospital, and University College, Dublin. The title of my presentation is Biomarkers in Oncology an overview.
A tumor marker or biomarker can be defined as a molecule produced by a tumor, or by the body in response to a tumor, and that aids cancer detection and, or management.
This summarizes the uses or potential uses of tumor markers. Firstly, tumor markers may be used for risk identification. What I mean by risk identification is the identification of healthy subjects who may be at risk of developing malignancy, perhaps many year later in life. Screening is somewhat similar to risk identification, in that focus is also on healthy individuals. However, in contrast to risk identification, in screening, the aim is to detect either early malignancy or a pre-malignant condition. Tumor markers almost never replace conventional histopathology for a primary diagnosis of malignancy. However, in some situations, tumor markers may aid cancer diagnosis. Following a diagnosis of malignancy, tumor markers may be used in, assessing prognosis, predicting response to therapy, predicting severe toxicity due to therapy, postoperative surveillance, and monitoring therapy in advanced disease. For the rest of the presentation, I will discuss these uses or potential uses of tumor markers, starting with risk identification.
We can now identify some individuals who may be at high risk of developing malignancy. We can do this because in a number of situations, we know the identity of the cancer predisposing gene. Those mutations in BRCA1 gene predispose to both breast and ovarian cancer. Similarly, mutations in the BRCA2 gene predispose to breast and ovarian cancer. Mutations in the APC gene predispose to a particular type of colorectal cancer known as the FAP type. Mutations in the MLH1/MSH2 and related genes predispose to another form of colorectal cancer. This form is known as HNPCC-type of colorectal cancer. And finally, mutation in the RET gene predispose the medullary thyroid cancer.