I was 35 when I was diagnosed kind of in early 2023.

I was diagnosed with Stage 3 rectal cancer at that point.

I was laying in bed and like, typing the symptoms that I had, and at the bottom it would always be stomach or colorectal cancer, and I was like, "That can't be me."

That's what my grandparents have to worry about.

When you look at the risk of being diagnosed with cancer at a young age, so between the age of 15 to 39, that risk has increased 40% from 1975 to now.

It's mysterious, it's concerning, and it's something that the whole cancer community is trying to work out right now.

Everyone's recognizing this is really serious.

I'm Mia de Graaf, and I'm a health editor at Business Insider.

Rates of cancer among young people are rising sharply worldwide, but particularly in certain countries that conform to what we would call a Western lifestyle.

So that's places like the US, Canada, the UK, Australia, certain parts of Europe.

These are all places that eat more ultra-processed food.

Things that are easy, cheap, and fast to get, places where people are often driving everywhere or have poorer sleep schedules.

So there are 14 cancers broadly that are increasing really rapidly among young people: breast cancer, colorectal cancer, endometrial cancer, esophagus, bile duct, gallbladder, head and neck, kidney,

liver, bone marrow, pancreas, prostate, stomach, and thyroid.

Those are all ones which are increasing in people under the age of 50.

The oncologists that I've spoken to who treat younger patients, the vast majority of patients they see actually seem like a picture of health when they come in.

They might be marathon runners or leading incredibly healthy active lives but still have this cancer diagnosis that comes up.

I've also spoken to a lot of young patients about how mind-boggling it is to get this kind of diagnosis at such a young age.

I was an adamant CrossFit enthusiast, and I had spent a lot of my 30s kind of refocusing my diet on trying to be what we all kind of expect to be healthier.

That, coupled with my young age when I got a diagnosis, that is something you're not supposed to worry about for decades. It was incredibly shocking.

When you are a young age, you are in this kind of sandwich generation.

You might be caring for your older parents, you might be starting to have a young family, you might be trying to save up money to buy a house.

At that time, getting a cancer diagnosis can be extremely destabilizing.

I was diagnosed in September of 2015.

I got a colonoscopy, and within a week, I was in surgery, and they took 80% of my colon out and started on this crazy long journey of colon cancer at 27.

A person born in 1990 has quadruple the risk of being diagnosed with colorectal cancer compared to a person born in 1950.

By 2030, colorectal cancer is going to surpass breast cancer as the leading cause of cancer death among young people.

The unfortunate thing about colorectal cancer in general is it really focuses on a part of our body that we as society have been conditioned to think of as embarrassing or things we don't want to talk about.

People even in my town still don't associate colon cancer with young people.

That's a huge, like, kind of stigma I'm trying to break.

The thing with colorectal cancer is that a lot of people were coming in with Stage 3, Stage 4, very advanced, and the tumors also looked more aggressive.

This is something obviously which was a huge conversation when Chadwick Boseman died.

He died of colorectal cancer, and it was Stage 3 or 4 by the time it was discovered.

And that's something that we are really seeing in young people.

In terms of what's causing the increased cancer rates among young people, there's many different factors that researchers are looking at.

Screening has increased, and it has helped us to detect more cancers for sure.

But that sharp rise that we are seeing in young cancers, it just cannot be accounted for alone by screening.

If this was accounted for by screening, we would actually be seeing a lot of early-stage cancers, and that's not really what's being borne out in the data.

We're seeing a surprising increase in young people with later-stage cancers, too.

One of the main factors we're looking at is diet, because eight of the 14 cancers which are increasing among young people are related to the digestive tract.

And our diet has changed a lot in the last few decades, and we know that the diets that we largely eat now in the US and in other high-income countries is not very good for us.

So that's more red meat, more sugar intake, more alcohol, low intake of water, food that is high in calorie, low in fiber.

It can increase your risk of diabetes.

That can affect how you control insulin.

These are all things that are linked to cancer.

So then you have inactivity.

So if you're living a more sedentary lifestyle, perhaps you're not moving around as much, you're not burning as many calories.

You don't have that regular movement which offsets inflammation in the body.

Poor sleep is a really big factor, which, if you speak to any oncologist, they will talk to you about sleep schedule.

Very often, people will be up sort of late into the night, and then they'll wake up very early to go to work, or you get a lot of night-shift workers now, which you didn't have in pre-1950.

One of the factors which is part of the conversation when we're talking about young cancers is our environment.

So obviously there are microplastics, toxins, pollution.

We do suspect that they're playing a role.

They're much harder to measure.

So children today seem to be exposed to chemicals that they probably wouldn't have been exposed to in the 1950s, and that's why we're trying to parse out,

is there a shift in terms of what children are exposed to in the environment now?

One of the rogue factors that people are speaking about is increased height.

So generally, humans are getting bigger.

We are all much taller these days.

There does seem to be a correlation.

With increased height is increased cancer risk marginally, but it is there, and one of the theories is that simply having more cells in your body increases the risk for more cell division,

which could increase the risk for cancer to grow.

The way you're born is a really interesting potential risk factor here for cancer.

So if you're born by C-section, you do technically, according to a few studies, have an increased risk of cancer.

There was a study done in Sweden recently that caused a big splash, which was that women who were born by a C-section had an increased risk of colorectal cancer in their young adulthood.

And we have seen other studies that being born via c-section increases a child's risk of leukemia.

When you have a vaginal birth, the baby is coated with microbes, and that seems to fortify their microbiome.

We've seen this sharp increase from 1990 to now.

We don't know exactly what that looks like from now on.

Can we reverse this trend?

Is it going in a linear fashion?

In terms of turning this trend around, the most important thing is research, obviously.

We need to better understand what the causes are, and until we better understand the causes, we can't make a societal effort to turn this trend.

A lot of attention is paid to what we could be doing as individuals.

So you'll hear everyone talk about diet and how you should be walking more, socializing, being part of a community, sleeping better,

drink less alcohol, don't smoke, don't do drugs, and then of course, do screenings and see a doctor.

But really, if we want to see a societal change and to turn this trend around, it is an infrastructure question.

So can we make cities more walkable, or can we make it easier for you to access fresh foods?

There are some positives.

The rate of cancer mortality is way down.

We've made so much progress in terms of treatment.

There are certain vaccines like the HPV vaccine that has dramatically reduced mortality from head and neck cancers, for example.

And then we're also preventing a lot of cancers that are to do with alcohol consumption and smoking.

Of course it's alarming, but the whole cancer community is rallying around this and is starting to pour investment and attention into this area to try and work out what's going on.

And I think that momentum is a real cause for optimism.