Devon Brown knew not to ignore it when she found a lump in her breast that just didn’t seem quite right.

“It felt very round and hard, so that was pretty abnormal,” she said.

A biopsy confirmed she was right to worry: the lump was cancerous. And so Brown, a 22-year-old Loveland resident, joined the unenviable, growing group of young people fighting cancers that generally had been considered diseases of later life.

Nationwide, the rate of cancers before age 50 increased about 4.4% in women from 2010 to 2019, but decreased about 4.9% in men. Breast cancer accounted for the largest share of early diagnoses, though rates increased faster for cancers of the digestive system. Most of the increase came from people in their 30s, with rates holding steady for other groups.

It’s not just an American phenomenon, either: cancer diagnoses worldwide in people between 14 and 49 increased 79% between 1990 and 2019, according to a study in the British Medical Journal of Oncology. Some of the increase may reflect that more people are being screened for cancers before age 50 — meaning more tumors are likely to be found — but the study’s authors suggested other factors also are involved.

Dr. Virginia Borges, director of the Young Women’s Breast Cancer Program at UCHealth, said that while breast cancer is most common in older women, about 27,000 patients under 45 are diagnosed each year nationwide. It is significantly rarer in women in their 20s, and those who develop breast cancer that young usually have a clear genetic predisposition, she said.

That was the case for Brown. She knew she had a family history of cancer and was planning to get genetic testing, even before her diagnosis. When she did get tested later, she found out she had a variant of the BRCA1 gene that increases the risk of breast and ovarian cancers. She opted to get a double mastectomy, and might have surgery to prevent ovarian cancer in the future.

“It scares me more to possibly have to go through this again than to just do that,” she said.

BRCA1 and BRCA2 are the best-known genes linked to breast cancer, but there are seven others that appear to increase risk, Borges said. That’s why it’s important to know your family history, since tests that only look for a few genes may miss others that raise risk, she said.

Family history includes not only parents and grandparents, but any aunts, uncles or cousins who had any type of cancer, Borges said. While breast cancer is extremely rare in men, some of the same genes increase the risk of other cancers, so having multiple male relatives with cancer may be a warning sign, she said. Cancers that were diagnosed before age 50 are especially important to note, as are ovarian cancers.

If genetic testing uncovers a reason to be concerned about cancer risk, people can start their screening earlier, Borges said. Some women consider mastectomies or removing their ovaries or fallopian tubes, if they’ve given birth to any children they intend to have, she said. (Research suggests ovarian cancer may often start in the fallopian tubes, and removing them would give patients another preventive option without pushing them into sudden menopause, as removing the ovaries does.)

“These screening tests don’t prevent the cancer, but they can help catch the cancer early,” she said.

Earlier this year, the U.S. Preventive Services Task Force issued a draft recommendation that women at average risk start receiving mammograms at 40, down from the previous recommendation that they wait until they turn 50. High-risk women have the option to start even earlier, if they and their doctors believe it’s appropriate.

While genetics are a strong clue to whether a person may experience cancer early in life, not everyone who gets breast cancer at a young age has one of the clear risky genes, Borges said. There could be risk factors that stretch back generations, but right now, no one’s sure what they are, she said.

“There’s no clear pattern,” she said.

Dr. Mary Beth Terry, a professor of epidemiology at Columbia University, said it’s still not entirely clear why early-onset breast cancer is rising, but research has been able to rule out some simple explanations. While rising obesity may be a factor in the increase in gastrointestinal cancers and increase the risk of breast cancer late in life, women who have obesity are at no higher risk of early breast cancer than those who are leaner, she said.

Likewise, decisions about childbearing don’t appear to be the main factor, Terry said. The earliest American cancer registry, which covers Connecticut, shows early-onset breast cancer has been rising since the 1930s — before hormonal contraceptives came on the market, and through relative booms and busts in fertility. And today, breast cancer is rising in younger women both in societies where women are more likely to delay or forgo having kids and in those where the average family has half a dozen children, she said.

For a long time, the assumption was that early-onset cancers were genetic and later ones were caused by people’s environments and behaviors, Terry said, but research has shown that’s a false dichotomy. The exact mix of factors varies from person to person, though.

“Every cancer is because of your genes and your environment,” she said.

The most likely environmental factors contributing to the risk are increasing rates of heavy drinking among young women; changes in the average person’s diet; differences in childhood infections, which shape the community of bacteria living inside us; and chemical exposures during puberty, pregnancy, lactation and menopause, Terry said. Those periods are particularly significant because the breast tissue is changing, she said.

There is a link between an increased risk of breast cancer and even moderate drinking, but if women don’t want to entirely stop, they can reduce the risk by not binge drinking, Terry said. The Centers for Disease Control and Prevention define binge drinking as four or more drinks in quick succession for women, and five or more for men.

“If you take something in fast, and it’s a carcinogen like alcohol, your body can’t clear it and repair the damage,” she said.

One factor that temporarily increases breast cancer risk for young women is having a child, Borges said. Giving birth and breastfeeding decrease the risk of developing breast cancer after menopause — when most diagnoses happen — but for reasons that aren’t clear, the risk goes up for the 10 years after having children. That said, even women who have genetic risk factors for breast cancer should be able to have children, if they choose, she said.

“We want women who want to have a child to have a child,” she said.

People who develop cancer earlier in life have more time to live with potential adverse effects from both the tumor itself and the treatment. While breast cancer can be more aggressive in young women, especially young mothers, there’s a good chance of curing those patients if they discover the cancer early, Borges said.

That means it’s particularly important to keep young patients’ goals in mind, particularly whether they want to preserve the option to have biological children, she said. That can involve either harvesting eggs before beginning chemotherapy, or giving a drug that basically puts the ovaries into a dormant state, limiting damage to the eggs.

“It’s kind of like turning them into Sleeping Beauty under the glass,” she said.

While breast cancer is still far less common in younger women than in those who’ve been through menopause, it’s important to be aware of your body and get screened if something seems wrong, Terry said. Female firefighters and military members have a somewhat elevated risk because of exposures on the job, and new mothers need to know that pregnancy hormones can feed any small tumors that might have been present in their breasts, she said.

“Women know their own bodies, and doctors shouldn’t say, ‘You’re too young for breast cancer,’” she said.

Brown urged other young women to find out their family history, and to get genetic testing and early screening if they find something that concerns them.

In her case, the tumor was at stage two, meaning it hadn’t spread outside the breast and is likely to respond well to treatment.

“My cancer is not only treatable, it’s curable. If I hadn’t found it as early, it might not have been,” she said.

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