Iowa continues to have the second-highest rate of cancer in the country and is one of a few states that has rising rates of cancer, according to an annual report by the Iowa Cancer Registry.
"It's kind of same story, different year," said Mary Charlton, a professor of epidemiology at the University of Iowa and the director of the Iowa Cancer Registry, which tracks cancer cases across the state.
The 2026 Cancer in Iowa report estimated 21,700 Iowans — 500 more from the previous year's estimate — will be diagnosed with cancer this year. Prostate, breast and lung cancers are projected to make up more than 40% of new diagnoses.
It also estimated that 6,400 Iowans will die of cancer this year, an increase of 100 from last year. Nearly a quarter of all deaths are expected to be from lung cancer.
"It just really continues to be of concern of how many different types of cancer that we're highly ranked in the country," Charlton said. "And such different types of cancer with different sets of risk factors, and they continue to have different geographic patterns in Iowa."
This year's report included a section on childhood, adolescent and young adult cancer in Iowa.
It found Iowa's rates of childhood and adolescent cancer are comparable to the national average, but cancer rates for young adults are higher.
"Where we do see where we have higher rates than the rest of the country is in our young adults, ages 20 to 39," Charlton said. "And in fact, we have the second-highest rate of cancers in our young adults in the country."
It's unclear what's driving Iowa's high cancer rates in adults, Charlton said, but mortality rates for children and young adults are low. Most cancers are caught early, and the state continues to see increasing rates of cancer survivorship overall.
Figuring out the mystery behind Iowa's high cancer rate has recently received much attention and funding from state lawmakers.
On Wednesday, Charlton and her University of Iowa colleagues presented their progress on a state-funded project seeking to shed more light on the state's cancer rate to lawmakers at a joint meeting between the Iowa House Health and Human Services and Environmental Protection Committees.
The two-year project, a joint project between the state and University of Iowa, began in July of last year and is about one-fourth complete.
Researchers said they have started looking into how demographic and behavioral factors could affect the rates of some of the state's top cancers like breast, prostate and lung cancer. They plan to start including genetic and environmental factors in the next phases of the project.
During questioning, several lawmakers expressed concern about the role the state's robust agricultural industry could have in elevating environmental exposure risks, like nitrate levels in drinking water.
"We all have more work to do because the quality of our water has to impact what we're doing," said Rep. Mary Lee Madison, D-West Des Moines. "And the fact that we're an agricultural state is another comparison that should come into the mix in order to discuss this topic in a real way and in a way that will give us results."
Charlton responded that researchers are working to find reliable data on things like nitrate and pesticide exposures to investigate the connection, but it's going to be very hard.
"I don't know how many of you in this room have ever only drank from one water source in your life — probably not very many," she said. "We don't have a longitudinal record of where you have all lived and all the water sources you drank from."
The cause of cancer is complex, Charlton said, and lowering the state's rates will likely require a combination of many tactics at the legislative level, such as raising the tobacco tax, supporting radon awareness and mitigation and finding ways to encourage people to lead healthier lives.
"There has to be more, I think, policies and legislation that support people in making healthy decisions," she said.
