Biomarkers of Cancer

Introduction

Any measurable specific molecular alteration of a cancer cell either on DNA, RNA, protein, or metabolite level can be referred to as a cancer biomarker. The expression of a distinct gene can enable its identification in a tissue with none of the surrounding cells expressing the specific biomarker. In the past decade, molecular dissection of the cancer by means of mRNA expression profiling enabled detailed classification according to tumor subtypes. The traditional system of tumor node metastases (TNM) has been the main tool for identifying prognostic differences among patients and for guiding the treatment. The TNM system is based on the macroscopic and microscopic morphological examination of pathological samples. Despite the advantage of uniformity for international communications and studies, there are many limitations of this system as a first line method for prediction and prognosis of cancer. It is difficult to distinguish related disease subtypes, which have different clinical outcomes. Hence there is a need for more exact molecular biomarkers for use in clinical practice. In recent years the discovery of cancer biomarkers has become a major focus of cancer research. The widespread use of prostate-specific antigen (PSA) in prostate cancer screening has motivated researchers to identify suitable biomarkers for screening different types of cancer. Biomarkers are also useful for diagnosis, monitoring cancer progression, predicting recurrence and assessing efficacy of treatment (Jain 2014). The advent of targeted therapies such as imatinib (Novartis’ Gleevec), trastuzumab (Roche’s Herceptin) and rituximab (Roche’s Mabthera), where a causal relationship has been established between drug target and therapy, drives the need for biomarkers for selecting the patients for a given therapy as well as for predicting drug resistance.

© Springer Science+Business Media LLC 2017

K.K. Jain, The Handbook of Biomarkers, DOI 10.1007/978-1-4939-7431-3_13

Table 13.1 Desirable characteristics of biomarkers for cancer

Purpose

Characteristics

Noninvasive

Low

Cost

Simple to Perform

Accuratea

Informative

(Discriminatory)

Screening

+ + +

+++

+++

+++

+++

Predisposition

+++

+++

+++

+++

+++

Early detection

++

++

++

+++

+++

Prognosis

+

+

+

++

++

Drug response

+++

++

++

+++

+++

Target for drug

NA

+

NA

+ + +

NA

© Jain PharmaBiotech

+ = low importance, ++ = medium importance, +++ = high importance, NA = not applicable. aLow rate of false-negative results

 
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