Genetics 6/1/2020

What is Cancer?

What is Cancer?

Learn what happens when cells break the rules

32 Cards

It’s likely that you or someone you know has been diagnosed with cancer.

But what exactly is cancer and why do people get it?

Your body is made up of trillions of tiny specialized units called cells - more than the stars in 100 Milky Way galaxies.

Each of your cells has a copy of your DNA.  Cells use DNA as a recipe to make proteins.

Different types of cells use your DNA in different ways for their specialized jobs.

Cells in your muscles work together to move parts of your body.

Cells in your gut absorb nutrients from the food that you eat.

Other cells send electrical signals through your brain.

But all cells normally live
by strict rules.

They have to respect their neighbors.

They can’t grow too fast.

They can only divide and copy their DNA to pass onto daughter cells so many times.

Cancer starts with just one cell breaking these rules.

Normally, your cells have many checks and balances that prevent rule-breaking.

But damage to your DNA can allow a cell to grow and divide when it shouldn’t.

A cell with enough DNA damage that is breaking the body’s rules can become a cancer cell.

A cancer cell can make many more copies of itself than healthy cells are allowed to.

A tumor is a large cluster of those copied cancer cells.

A tumor can start out harmless but become malignant, meaning it can spread to nearby tissue.

Cancer can start almost anywhere in the human body.

Each cancer is unique.
No two people have the same cancer, even when it affects the same tissue.

Each cancer has its own set of mutations that allow it to break the rules.

A mutation is a mistake that happens in your DNA code.  It can happen within a gene.

Gene: a unit of DNA that is a recipe for making protein or performing some other function in your cells.

Some people inherit mutations from their parents that make it easier for cancer cells to form.

Things in your environment and lifestyle can also lead to new cancer-causing DNA damage.

These things can damage your DNA: Sun exposure, toxins, chemicals in tobacco smoke, even some viruses.

Your DNA can also make mistakes copying itself, especially as you age.

Today, genetic testing is more important than ever in the fight against cancer.

Genetic testing uncovers cancer-causing gene mutations.

If we can find the mutations driving a person’s cancer, we can know how their cancer cells break the rules.

Knowing how cancer cells are able to grow gives us a better idea of how to kill them.

Continue learning

There are more than 100 types of cancer, and we are continually discovering more about them every day.

Learn more here: www.cancer.gov
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