The term diagnosis refers to a set of tests or investigations involving various
biological samples such as tissue, body fluids and/or other irregularities in the body.
While diagnosis is a broad term, examining the abnormalities in macromolecules -
DNA, RNA or proteins at the level of nucleic acids and amino acids makes it a
molecular diagnosis. As the world of diagnosis is rapidly expanding and advancing,
newer minimal invasive techniques are being researched to spare the patients from
various discomforts. Healthcare professionals are also aiming towards personalized
medicine, making the treatment more selective and accurate, at the same time ensuring
patients’ safety. This is being achieved by high throughput analysis, though currently
still economically very challenging. Technologies such as Histopathology, Polymerase
Chain Reaction (PCR), Flow Cytometry (FC), Immunohistochemistry (IHC), Capillary
Electrophoresis (CE) and Fluorescent In Situ Hybridization (FISH) are already in use
for routine diagnosis in cancer. Though, high throughput technologies like, Next
Generation Sequencing (NGS), Microarray studies, miRNA detection, ChIP
(Chromatin Immune-Precipitation) and MeDIP-seq (Methyl-DNA Immunoprecipitation),
SELDI-TOF MS (Surface-Enhanced Laser Desorption/Ionization Timeof
Flight Mass Spectrometry), quantitative proteomic analysis and many more are
triumphing into the diagnostic avenue, they are restrictively catering to high socioeconomic
groups in developing countries. An average citizen is still missing out on
these forms of diagnosis and personalized treatments, thus devaluing the very aim of
diagnosis and treatment in cancer. It becomes the pursuit of diagnostic community to
come up with cost effective investigations and affordable treatments that could be
efficiently validated. In this chapter, we briefly discuss the differences between
diagnostic, prognostic and predictive tests along with a detailed understanding of genes
and gene products that form the basis of molecular diagnosis in cancer. We also focus
on currently available high-throughput methods and the challenges associated with
them.
Keywords: Capillary Electrophoresis, ChIP, Flow Cytometry, Fluorescence
in situ Hybridization, Gene Aberration, Histopathology, Immunohistochemistry,
MeDIP-seq, Microarray, Molecular Diagnosis, Next Generation Sequencing,
Polymerase Chain Reaction, SELDI-TOF MS.
