Dear Austin,
I love a predictable schedule. Knowing when to eat, sleep and answer your questions keeps me chill.
That how the cells that make up our bodies work, too. They grow and die on a predictable schedule. Our bodies constantly make new cells to replace the ones that die. They grow for a set time and then die, too.
But sometimes cells grow out of control. They may grow faster or for a longer time than normal cells. They ignore the signals that tell a cell it’s time to die. They can even spread to other parts of the body and start growing there. That’s cancer.
That’s what my friend Weimin Li told me. He’s a medical doctor and scientist at Washington State University. He studies breast cancer.
He said that cancer happens because of changes in our genes. They’re called mutations.
Inside each of your cells, you have a copy of your DNA. It’s like a recipe book that tells your body how to make all the proteins that make your body work. A chunk of DNA that tells your body how to make a specific thing is called a gene.
When your body makes new cells or proteins, it copies your DNA. Usually, it copies it exactly right. But sometimes it makes a little mistake or mutation. That’s one way cancer starts.
Cancer can also start if something in the environment changes your DNA. That mutation can come from chemicals or viruses. It could come from getting too much of the sun’s light or pollution in the air, soil or water.
“Exposure to harmful substances, unhealthy lifestyles, aging and infections may cause cancers,” Li said. “This is a good reminder for us to take care of our living environment and our health.”
Sometimes DNA changes get passed down from our parents. That’s why doctors ask if anyone in your family has ever had cancer.
Usually, mutations are no big deal. They don’t make a difference in how your body works. They don’t cause cancer or any problems at all.
But sometimes mutations happen in genes that manage the predictable schedule of your cells. It could change the genes that tell your cells to grow or stop growing. It could change the genes that tell your cells when it’s time for them to die. It can change the genes in charge of fixing mistakes or changes in your DNA.
Those are the mutations that can cause cancer.
Cancer can be scary to think about. The truth is that it’s something that can happen to all animals. Even the dinosaurs sometimes had cancer.
The good news is that scientists and doctors like Dr. Li are working hard to figure out new ways to fight cancer. Other scientists and public health experts are helping people avoid things that cause cancer—like smoking, pollution and forgetting to wear sunscreen.
It’s one of the ways we can see science helping make our lives better.
Sincerely,
Dr. Universe