Table 2.

Comparison of selected emerging methods and technologies for use in cancer epidemiology

Method/Technology	Strengths	Weaknesses
mtDNA polymorphism	Whole genome can be sequenced for a large number of samples because of the small size of the mt genome (16.5 kb)	mtDNA sometimes can become integrated into the nuclear genome, and identifying the integrated mt genome in the nuclear genome is tedious
mtDNA copy number	May provides additional information for identifying risk- and survival-associated biomarkers	Experiments should be done very carefully because the number of copies varies during the disease development
Methylation profiling	Provides a mechanism for studying gene activation/inactivation without a change in the genome	Careful selection of the method is key to avoiding false- negative and false- positive results; tissue specificity can be a concern
miRNA profiling	Requires a small amount of sample and provides additional information to understand epigenetically mediated gene regulation; information can be used in targeted intervention studies	Tissue specificity can be a concern
Nuclear magnetic resonance (NMR)	Quantitation of analytes is accurate with full automation and high-througput capacity and high reproducibility	Identifying products can be challenging because of its insensitivity in detecting metabolites with concentrations in micromole range
Mass spectroscopy (MS)	Extremely sensitive, can detect analytes at picomole range; requires small biospecimen volumes	Requires expensive consumables; poor representation of highly polar metabolites
Metabolite profiling	Can be done easily in patient biofluids	Standards for all metabolites are not available
Telomerase activity and telomere size variation	Suitable for paraffin-embedded tissue samples	Since the length of telomere changes with age, subject selection is very critical

mt: mitochondrial