Many of the terms associated with biomarkers or biomarker testing require an understanding of basic genetics. As such, the following terms may be helpful for members of the multidisciplinary team.
An increase in the number of copies of a gene and, subsequently, the RNA and protein made by that gene. In oncology, amplification may cause cancer cells to grow or become resistant to anticancer drugs.1
The structural form of DNA that is found inside the nucleus of a cell. All human cells normally contain 46 chromosomes.1
DNA (deoxyribonucleic acid)
The hereditary material in humans and almost all other organisms.3
A mutation within a gene that promotes cell growth or survival advantage, leading to cancer.4
The protein-coding regions of the genome, representing approximately 1-2% of the complete DNA sequence.5
The complete set of DNA in an organism.1
A series of molecular actions within a cell that result in a specific cell function or end point.1
A gene responsible for cell growth that has been mutated to increase its function and thereby may result in cancer development. Oncogene mutations can be inherited or caused by environmental exposures.1
The increased production of a protein or other substance made by a gene. In oncology, overexpression may play a role in cancer growth.1
The number of sets of chromosomes. Abnormal ploidy (e.g., trisomy, hypoploidy) is related to cancer incidence.1
A molecule made of amino acids that control cellular function.1
RNA (ribonucleic acid)
A singular strand of hereditary material that regulates cell functions or protein production.1
A gene responsible for preventing cell growth that has been mutated to decrease its function and thereby may result in cancer development. Tumor suppressor gene mutations can be inherited or caused by environmental exposures.1
There are two types of genetic mutations that affect cancer progression or treatment response that are commonly referred to as germline or somatic mutations. The main distinction is that germline mutations are inherited, and somatic mutations are not. However, these are not mutually exclusive, and it is possible for an individual to have both germline and somatic mutations. For example, an ovarian cancer patient with the BRCA germline mutation may also have a somatic PIK3CA mutation.
There are four main types of genetic mutations. Each may result in changes to protein production or function that could influence cancer progression or treatment response.