What is the difference between genetics and genomics?

Although they are used interchangeably, the terms “genetics” and “genomics” are not synonymous. Both involve the study of genetic material and both are derived from the Greek word gene , which means birth or origin. But the similarities largely end there. Although genetics and genomics are complex topics, the difference between them is much simpler: one (genetics) refers to one a person ‘s genetic makeup is usually used for, and the other (genomics) refers to a tumor molecular structure. You can also think of genes in terms of inherited traits and genomics in terms of cancer-specific mutations.

What are they

Genetics is the study of the genes that people inherit at birth, and that are passed down from their families through generations. Every cell in the human body contains an entire strand of DNA, and each strand is filled with genes that carry instructions for certain traits, such as blue eyes, red hair, or perhaps an increased likelihood of developing some types of cancer. Genetic testing can help determine a person’s risk of developing cancer and other diseases.

Genomics generally refers to the study of mutations in genes that can drive different behaviors of cancer, from how aggressive it is to whether it spreads to distant parts of the body. Every cell in the human body contains tens of thousands of genes, but mutations in a single gene can cause cells to grow out of control and lead to the growth of tumors. Often, cells in a tumor change over time because their genes continue to mutate. Therefore, genetic testing can vary greatly over time, even when performed on the same tumor. When the molecular makeup of the tumor changes, the patient may develop resistance to a particular treatment. “Unfortunately, cancer is very intelligent, and it is common for treatment to stop working because the cancer is now a different cancer,” says Melanie Korpman, MD, a certified genetic counselor licensed at our hospital in Philadelphia.

What the tests show

Both tests—the two that map a person’s DNA profile and those that look for genetic abnormalities in a tumor—can be helpful in treating cancer, although genetic and genomic testing are used in very different ways and in very different circumstances. In the world of cancer, genetic tests look for genetic mutations that a patient may have inherited through their family, which is why they are recommended for people with a family history of a certain type of cancer. Those who test positive for a BRCA1 gene mutation, for example, have an increased risk of developing breast and ovarian cancer.

Genomic testing is used to identify mutations that have nothing to do with heredity, but occur within the cancer cell itself, either due to an external cause, such as tobacco use or exposure to sunlight, or due to an intrinsic factor, as a random molecular change within the cancer cell. Cell – dungeon. cell. These changes can determine why a tumor behaves the way it does, such as why it is growing or spreading. If the mutation matches a known abnormality, your oncologist may recommend a specific targeted therapy designed to target that mutation. This type of test may be recommended for people whose cancer has stopped responding or hasn’t responded well to conventional treatments such as chemotherapy and radiation.

How do they direct the treatment?

In both genetic and epigenetic testing, your oncologist may recommend treatment based on your results, such as preventive surgery in the case of genetic testing or a specific type of drug therapy in the case of genetic testing. Since most cancers do not develop from inherited genes, but from mutations that occur throughout patients’ lives, researchers hope that continued advances in genomic testing will help better identify specific tumor mutations and treatments tailored to each individual.

One clinical trial that uses genomic testing to better understand cancer treatments is the TAPUR study. TAPUR, or Targeted Agent Use and Characterization Study, is a clinical trial aimed at improving our understanding of how commercially available cancer drugs work in a broader range of cancers, by matching drugs to tumors with genetic mutations. .

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