CATHY WURZER: More and more younger people are getting cancer. If that sentence pulls you up short, it should. There’s a new study published in the Journal of the American Medical Association that shows cancer in people younger than 50 has increased over the last 10 years, especially among women ages 30 to 39. The highest increases were in gastrointestinal, endocrine, and breast cancers. For more, we’re joined by Dr. Kathryn Ruddy. She’s a medical oncologist and the director of Cancer Survivorship at Mayo Clinic. Doctor, welcome.

KATHRYN RUDDY: Thank you so much.

CATHY WURZER: Early onset cancer is pretty unusual, isn’t it? What were your initial reactions when you read through the study?

KATHRYN RUDDY: Yeah. Well, this is a major concern. And I’m a breast medical oncologist, so this is certainly something that we’ve seen in other studies and certainly something that we need to figure out what to do about.

CATHY WURZER: The obvious question is, what’s going on?

KATHRYN RUDDY: Yeah. There are probably multiple things contributing to these trends. And I think one concern is that obesity rates may be part of the problem. But there are also things we just don’t understand about why we are seeing increased risks of certain cancers.

CATHY WURZER: It’s multifaceted. What about early detection through cancer screening programs? How much of the increase could be due to that perhaps?

KATHRYN RUDDY: Well, it would be great if this were just due to better screening. But in many age ranges and for many different types of cancer, we don’t have screening in younger patient populations. So for example, for breast cancer, most average risk women are not recommended to start mammograms until age 40. So when we’re seeing that younger women are experiencing an increased risk, really, mammograms would not be detecting those.

CATHY WURZER: Say, I understand that only 5% to 10% of all cancer cases can be attributed to genetic defects. About what? 90% to 95% have their roots in the environment and lifestyle. When you look at the most recent study, could the Western diet and lifestyle be among the contributors to this rise?

KATHRYN RUDDY: Yeah. I think that is a significant possibility, and we do worry about what type of dietary components might be contributing to this. And certainly, as an oncologist, something I think about is what can we do to turn this trend around? Are there dietary changes that we can make as a society that could get these rates coming down again?

CATHY WURZER: I noted that among the 14 cancer types on the rise that they studied, eight were related to the digestive system. And the food we eat obviously feeds the microorganisms in our gut, our microbiome. How much of that the science of the microbirome– microbiome, sorry– plays into cancer?

KATHRYN RUDDY: Well, research is very active in this area because this is a very key question. If we could figure out certain ways to affect the microbiome in a positive way, of course, we would love to figure out what those ways would be. And there are many researchers working on this.

And as you point out, gastrointestinal cancers are on the rise. And in fact, I want to emphasize that the that the recommended age for colorectal cancer screening just decreased. We used to have a recommendation for starting colon cancer screening at age 50, and it’s now 45 in response to this increased risk in younger patients.

CATHY WURZER: Say, going back to breast cancer for just a moment here in terms of young women developing breast cancer, how much of that is also environmental versus, say, genetic? Do we know?

KATHRYN RUDDY: We don’t really know. Most cases when I’m seeing a patient with a newly diagnosed breast cancer, I don’t really know what has caused that cancer. As you say, it’s a very small minority who carry one of these inherited genetic mutations that has a high risk of breast cancer and therefore we can point to say, OK, that that’s probably what’s at play here.

And in most cases, we don’t know. Certainly, there are some trends that may be contributing to the increased risks as more of us wait until our 30s or 40s to have pregnancies. That may be a factor in these increasing rates. But we really don’t have the full answer here yet.

CATHY WURZER: I wonder, are there common misperceptions that the public might have around cancer in younger people?

KATHRYN RUDDY: Yeah. Well, I think most of us rightly think of cancer as a disease of aging. And it’s certainly true that risk of cancer goes up as we age. But I think a misperception would be to think that younger patients can’t have cancer and that new symptoms shouldn’t be discussed. We all really should be talking to our primary care providers about family history, medical history, lifestyle factors, and also symptoms that might warrant testing or screening for cancer.

CATHY WURZER: Because I’m sure you hear the phrase– I know I have– well, you’re too young for that kind of cancer. And there’s those messages that go out that, as you say, you have certain symptoms and you just can’t believe it would be cancer. So maybe people don’t get screened or tend to ignore those symptoms.

KATHRYN RUDDY: Exactly. I think these are really important messages to get out that just because you are young does not mean that you could not have cancer. There’s really no such thing as too young when we’re talking about the possibility of a cancer risk.

CATHY WURZER: How should the medical community respond to something like this study?

KATHRYN RUDDY: Well, I think you know this study confirms what other studies have identified previously with regard to the increasing rates of early onset breast and gastrointestinal cancers. And I hope that therefore, we as a medical community are going to be working even harder to develop interventions that can reverse this trend. We need to understand, are there lifestyle changes, even medications that might help to get these rates coming back down again?

CATHY WURZER: By the way, should younger folks who may be at risk seek out screening on their own and advocate for themselves?

KATHRYN RUDDY: Well, I think it’s hard to seek out screening on your own. But what you should do is talk to your primary care provider about what makes sense for you from a screening standpoint based on your history and other factors.

CATHY WURZER: OK. Anything else you want to add about this study?

KATHRYN RUDDY: No, I just want to thank you for covering it. This is a really important issue.

CATHY WURZER: All right. Dr. Kathryn Ruddy, thank you so much.

KATHRYN RUDDY: Thank you, Cathy.

CATHY WURZER: Dr. Ruddy is a medical oncologist at Mayo Clinic, and she also is a director of the Cancer Survivorship Program at Mayo Clinic.