In a previous column, I wrote about how teens feel invincible. And to some extent, that’s true. We teenagers have our entire lives ahead of us, and the possibilities seem endless.

But what about when they’re not? What about the teens who may not have the world ahead of them, unlike so many of their peers?

About a year ago, I received some bad news about one of my childhood friends. This girl, whom I had known since we were 5, had cancer. I was shocked.

We celebrated birthdays together, routinely visited each other’s houses for playdates, had sleepovers and participated in the same recreation groups. Looking back, I remember thinking of her as one of my closest friends.

Once I switched school systems, our relationship began to fade away. However, I still thought of us as friends, even though we didn’t see each other quite as often.

But if we ever ran into each other around town, we always stopped to say hello and reminisce about all the fun we had when we were younger.

So when I found out she had cancer, I was stunned. I wanted to do something.

Initially, I sent her a card to let her know that I remember what an amazing person she is and how many memories we shared.

But I wanted to do more. So, I donated eight inches of my hair to Wigs for Kids. I wanted to make a small difference in the life of a child and show that I care, even if I didn’t know them personally.

Every child, teen or adult reacts differently to being diagnosed with cancer or finding out someone they know is suffering from this disease. Although I am just a teenager, I know many people who have had cancer. Each story is different and some people live with cancer for a lifetime.

I would never presume to know how they feel, because I could never put myself in their shoes.

I imagine that getting a cancer diagnosis could significantly alter your day-to-day life. You don’t need to inherit a genetic condition, get a certain virus or lead an unhealthy lifestyle to have cancer.

The reality is, cancer can happen to anyone at any point in their life.

Who doesn’t know someone who has cancer? My grandfather died of cancer. My aunt died of cancer. My mom’s friend had cancer. Kids in my elementary and high school had cancer.

Nearly 40 percent of people will be diagnosed with cancer at some point in their lives, though the death rate is much lower.

For teenagers, adolescence can be a difficult time. I imagine it only becomes more of a challenge while battling cancer.

Teenagers want to feel untouchable and youthful, and I have read that many teens with cancer might feel fearful, sad or angry about their situation. Teens want to be independent, free from adult supervision, and it’s this age where we are finally starting to gain some freedom.

It might be frustrating to fellow teens if they need to ask for help more than they’d like. I believe something that may help fellow teenagers, or anyone going through cancer, is your support.

You don’t need to donate your hair to show someone with cancer that you care about them. Something as simple as a call, text, email or card can make a difference in a cancer patient’s life. Showing that you are there for someone may have more of an impact than you realize.

As teenagers, we feel immortal. When we see someone we know fighting for their life, perhaps a friend or relative diagnosed with cancer, it makes us question our own.

Maria Proulx of Ledyard is a sophomore at St. Bernard School in Montville.