Why does so many things cause cancer.


Take smoking cigarettes, everyone says that causes cancer. But how? I thought cancer was just a malfunction in the cells? I know I’m wrong it just doesn’t make sense to me

In: Biology

You’re right that cancer is a malfunction in the cells, but that malfunction can be caused from outside sources. An an easy example, sunlight is known to cause skin cancer. That’s because harmful and powerful UV rays from the sun (mostly UVB, if we’re being picky) can actually damage the DNA in our skin cells directly, and sometimes that damaged DNA will get copied over and over, causing skin cancer.

Smoke is the same way – some of the harmful chemicals in smoke have that same effect of damaging the DNA of our cells, and sometimes that damage can produce a cancerous cell that starts to replicate out of control. In the case of smoking, most of that damage is happening in the lungs, though it can also affect parts of the throat and mouth as well, causing cancer in any of those areas.

The chemicals inhaled during smoking interact with your cells and can change your DNA. This now “incorrect” DNA tells your cells to do the wrong thing such as start rapidly reproducing, causing a cancerous growth.

The reason so many things can cause cancer is because there are a lot of things (chemicals, radiation, etc.) that can interact with the molecules that make up our DNA. In fact, your DNA is messed up often but it typically can repair itself. But the more you smoke, the more the DNA has to repair itself, the higher the chance is it makes a mistake while repairing itself.

How come so many different things can pop a tire. I thought a popped tire was just a hole in the tire?


Well the cells, like a tier can be easily damaged in any number of ways. DNA is delicate stuff and get altered very easily. And many of those alterations are going to result in cancer.

That’s because everyone is using the wrong language. Carcinogens do not *cause* cancer, they increase they risk of getting cancer. I’m not sure it’s a perfect analogy, but it can be helful to think of them as gasoline. Gasoline does not cause fire. However, if you soak your clothes in gasoline, your chance of catching on fire increases quite dramatically.

Every time DNA replicates, there’s a chance of a mistake that leads to cancer. Damaging these cells leads to more replication to heal or replace these cells. Therefore more opportunities to get cancer.