Women under 50 are more likely to get cancer than men the same age, according to a study from the American Cancer Society published January 2025. 

The cancer incidence rate in women under 50 was 81% higher than in men in 2021, an increase from 51% in 2002, according to the study. 

Much of it has to do with an increase in breast and thyroid cancer diagnoses, Heather Nelson, the associate director of cancer prevention and control at the Masonic Cancer Center, said. 

“There has been a well-documented increase over time in the overdiagnosis of thyroid cancer,” Nelson said. “We’re detecting cancers that do not increase cancer mortality, and that impacts young women more than young men because women are more likely to get treatment.”

Nelson said the increased risk in breast cancer is more concerning for young women and is likely caused by lifestyle and environmental exposures that scientists have yet to identify.

Scientists understand that increased obesity, decreased fertility and alcohol consumption all contribute to developing breast cancer under the age of 50, Nelson said.

“One of the protective factors for breast cancer is having a baby,” Nelson said. “We see decreasing fertility that could eventually lead to an increase in breast cancer in the population.” 

Nelson said that when women get pregnant and their breasts prepare to produce milk, the breast tissue fundamentally changes due to hormone cycle changes. Scientists think these changes in breast tissue decrease breast cancer risk in women as their body responds differently to the hormone cycles after the breast begins producing milk and changes the tissue. 

Obesity and alcohol consumption likely can lead to breast cancer because of inflammation of breast tissue, Nelson said. The inflammation burdens the body and puts stress on the breast cells, causing mutations and the growth of abnormal cells. 

Schelomo Marmor, an associate professor in the division of surgical oncology, said environmental exposures from things we have not identified yet also contribute to the rise in cancer rates. It is more common for women to work in jobs requiring manual labor, which leads to new environmental exposures.

According to the U.S. Bureau of Labor Statistics, women made up about 26% of the agriculture workforce, 15% in mining and 10% in construction as of 2019. 

“Women working in the iron ore industry, or other things that typically women were not doing or were not allowed to do a few decades ago,” Marmor said. “It’s now more common for them to be in those types of worksites so environmental exposures are more common.”

While cancer rates have gone up, mortality rates for most cancers have gone down, according to the study. Regular cancer screenings to catch the disease early and improvements in treatment contribute to an overall decrease in cancer-related deaths.

Cancer mortality rates among all age groups and genders in Black and Indigenous people in America increased, Nelson said.

Nelson said social inequalities like access to health care and persistent poverty in these groups impact cancer and mortality rates in these communities. They are also less likely to have access to screenings and treatment.

“We know people experiencing persistent poverty are more likely to have environmental exposures that lead to cancer,” Nelson said. “All three of those points, environmental exposure, screening and treatment are impacted by persistent poverty and social inequalities.”

The increased cancer mortality rate among Black and Indigenous communities in Minnesota is consistent nationally, Nelson said. 

“We see increased colorectal cancer and lung cancer in American Indians both for the number of cancer cases and cancer mortality,” Nelson said. 

Nelson said there are groups at the University investigating ways to help those communities stop smoking rates and increase early cancer screening rates. 

Black people have increased rates of prostate and breast cancer mortality, Nelson said. Similar initiatives at the University work to target the contributing factors like increased smoking and alcohol consumption to these higher mortality rates. 

Nelson said people should be aware of their drinking habits and have an active lifestyle to decrease their cancer risks. 

“We’ve been hearing a lot more about alcohol as a cancer-causing agent,” Nelson said. “I think that’s a place that young women should be aware of the risks that accompany heavy drinking. Also maintaining an active lifestyle to have a healthy weight can improve their chances of not getting cancer.”