A Bottom Line Review of Cancer Genomic Testing
As previously stated in prior posts, years of research has focused on genetic testing of cancer to advance personalized medicine. The field of cancer genomics has taken off, but it remains unclear what the impact of these genetic testing means. There are 3 basic types of cancer genetic testing: select testing, broad base testing and whole genomic testing. Select testing represents routine individual testing of specific genes that express mutations (e.g. EGFR mutation or ALK gene rearrangement for lung cancer), which has been covered by Medicare and insurance for years. Broad-based genomic testing represents genetic testing for a large panel of known genetic mutations found in specific cancers. Cancer typically result from a large number of mutations. Recently, Medicare approved coverage of some FDA-approved broad based genomic testing. It is anticipated that insurance will follow Medicare's decision. Broad-based genomic testing is expensive and costs approximately 5000 dollars per tests. There are some caveats for Medicare coverage of broad based genomic testing. Whole genomic testing represents sequencing the entire DNA of cancer cells, which includes looking for mutations of genes that express proteins (a term called coding sequences) and non-coding DNA sequences that regulate the level of proteins expressed from coding sequences. However, whole genomic testing is not covered by Medicare. It is likely that this type of diagnostic testing will also be expensive.
The fundamental questions from genomic testing are:
1. Does broad based and whole genomic testing improve patient survival?
2. How many actionable treatments are even available from the results of these tests?
3. Can these genetic diagnostic tests instruct a physician what the approximate drug concentration and dose are necessary for killing cancer cells?