According to a recent report by the American Cancer Society, breast cancer diagnoses

climbed by 1% annually from 2012 to 2021, and that increase was actually sharper in people

under the age of 50.

With so-called early onset cancers on the rise, scientists are working to sort out the complex

tangle of factors that can contribute to someone's risk.

For Scientific American Science Quickly, I'm Rachel Feltman.

I'm joined today by Dr. Jasmine McDonald.

She's an assistant professor of epidemiology at Columbia University's at Mailman School of Public Health.

Thank you so much for coming in to chat with us today.

Thank you for having me.

So I know that you study breast cancer, but can you tell me more about your particular area of expertise?

I got my training in basic science, and I was very interested in signaling pathways

and how those pathways are associated with disease. And now I'm a molecular epidemiologist,

and so I'm very much interested in the progression of developing breast cancer, but how that

happens across a woman's life course. So from in ural to

puberal to postpartum, those periods of time where we know the breast tissue is more sensitive

to outside assaults or exposures and how that plays a role in developing breast cancer.

And what has changed about breast cancer, risk, or diagnosis in recent years?

There's been an increase in early onset breast cancer.

So this means that there's an increase in young women developing breast

cancer before the age of 50. Some even defined it as developing breast cancer before the age of 45.

This is very concerning. As cancer is usually considered a disease of old age, you have to live long enough to develop cancer.

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