A marvellous thing made up from a great many microscopic marvellous things, called cells. The human body is made up of over thirty trillion cells. To put that into perspective, if you had one second for every cell, you would have just shy of one million years.

Every time I think about it, I’m amazed that if you mash 37 trillion cells together, you get a living, breathing, thinking person, capable of dreaming, dancing, and reading newsletters.

Our cells are programmed largely by their DNA. It determines the type of cell, when to grow, and when to divide. It even includes a self-destruct sequence in case a cell is too damaged or faulty. Usually, these internal checks and balances are enough to keep our bodies running normally, but what happens when we lose our instruction manual? When our instruction manual is damaged or lost, our cells no longer know what to do. Our DNA is composed of many different genes, so if our DNA is an instruction manual, each gene is like a specific step that tells the cell exactly which protein to make.

Now, you’re probably thinking, “What harm is one bad cell going to do in a sea of 37 trillion?” Well, cells divide by doubling, which means that one cell becomes two, two becomes four, and so on, until five hundred thousand becomes one million, just like that. And because cells pass on their DNA as they divide, each cell carries the same damaged DNA as the first, all missing their instruction manual.

This is where things start to become problematic. As you rightfully thought, one cell can’t actually do much harm, but millions of cells, all growing and dividing at an uncontrolled rate, will start to compete with your healthy cells. They’ll start to steal nutrients, oxygen, and everything that your cells need to stay alive. Then eventually, when a tumour grows large, even the physical size becomes an issue. A tumour can press up against arteries or veins, blocking the flow of blood. They can invade nearby tissues, break barriers, and pinch nerves. They can interfere with virtually all processes that our organs need to stay healthy, organs that our bodies rely on to keep us healthy - to keep us alive.

Well… it really comes from everywhere. You may have heard of “carcinogens” before. Carcinogens are cancer-causing agents that lead to cancer by damaging our DNA. They are, quite literally, everywhere. From the UV rays of the sun to burnt toast and the paint on our walls, we’re exposed to carcinogens everywhere we go. Sometimes we can even get DNA damage because our cells made a mistake when dividing!

I know that a lot of this can be scary, but it’s not as bad as statistics make it out to be. Yes, many people will get cancer in their lifetime. And yes, we’re exposed to cancer-causing agents on a daily basis. But we also repair that damage every day. We can actually tolerate a lot, and our cells do an incredible job regulating themselves, all 37 trillion of them. On top of that, even if a single cell goes off the rails, we have other cells in our body that can help keep them in check, but that story is for another time. There is also incredible research being done on cancer, every single day, with people dedicating their lives to better understanding the disease so we can create new therapies and treatments. Cancer can be scary, but we’re most afraid of what we don’t understand, and I want to help with that. I want to talk about the science behind cancer and cancer research, to make it a little less daunting.

I hope you learned something today, and maybe you’ll have an answer if someone asks you, “What actually is cancer?”

See you next week!