Broad molecular profiling tests look at all the genes in a cancer tumor -- called the genome -- to see if any mistakes have accumulated over time in the DNA, which doctors call genomic alterations or genetic mutations.
Other names used for broad molecular profiling include:
- molecular profiling
- next-generation sequencing
- comprehensive genomic profiling
Cells are the building blocks of every living thing — from tomatoes to ladybugs to salmon to people. The instructions that tell a cell what to do are in genes within the center of the cell. Those genes are made of DNA (deoxyribonucleic acid). DNA can change or be damaged over time. Some DNA changes are harmless, but others can cause disease. Cancer cells are “born” when genomic alterations in DNA tell cells to grow faster and behave differently than they should.
There are two types of genomic alterations: those that are inherited and those that happen over time.
Inherited genomic alterations are passed down from parent to child, such as an inherited BRCA1 or BRCA2 gene mutation. Inherited genomic alternations are called germ-line alterations or germ-line mutations. Genetic testing is used to find inherited genomic alterations.
Genomic alterations that happen over the course of a lifetime, as a result of the natural aging process or exposure to chemicals in the environment, are called somatic alterations or somatic mutations. Broad molecular profiling tests are used to find somatic genomic alterations in a cancer tumor.
Broad molecular profiling tests can identify four types of somatic genomic alterations:
- base substitutions: one of the amino acids making up a strand of DNA is substituted for another
- insertions and deletions: insertions have extra amino acids inserted into a new place in the DNA strand; deletions mean a section of the DNA is gone
- copy number alterations: sections of DNA are repeated
- rearrangements: the amino acids making up the DNA are rearranged into a different order
Knowing the type or types of somatic genomic alterations in a cancer tumor can help your doctor:
- figure out the best targeted therapy medicine to target one or more of the alterations
- match you to a clinical trial that is studying treatment for one or more of the alterations
There are a number of broad molecular profiling tests available, including:
- FoundationOne, made by Foundation Medicine
- IntelliGEN Oncology Therapeutic Panel, made by Integrated Oncology
- Molecular Intelligence, made by Caris Life Sciences
- large academic institutions have their own in-house broad molecular profiling tests
Depending on the type of cancer a person had been diagnosed with, broad molecular profiling tests are done on a sample of tumor tissue, blood, or bone marrow.
Right now, broad molecular profiling tests are most often used to test the genome of advanced-stage cancers to match the cancer tumors with targeted medicines.
Broad molecular profiling tests are different than tests like the Oncotype DX test. Tests such as Oncotype DX, MammaPrint, Mammostrat, Breast Cancer Index, and the Prosigna Breast Cancer Prognostic Gene Signature Assay focus on a specific type of cancer, such as breast cancer, and look at a set of specific set of genes, not the entire genome. These tests also are usually done on early-stage disease.
Broad molecular profiling is not yet the standard of care for most types of cancer, but there is movement in that direction. Because it is not the standard of care yet, not all insurance plans cover broad molecular profiling tests. If your doctor recommends broad molecular profiling testing for you, be sure to talk to your insurance company to see if the test is covered. If it is not covered or only partially covered, most of the companies that make broad molecular profiling tests offer some sort of financial assistance. Once you and your doctor decide on the test you will have, you can contact the company and ask about assistance.