Two recent reports from the Iowa Cancer Registry revealed that four types of cancers are contributing to Iowa having the second-highest cancer incidence rates — rate of new cancer cases — in the country.
Despite cancer incidence rates decreasing on a national level, Iowa is one of six states to have a rising rate for the past couple years. Of those six states, Iowa is the only state located in the Midwest, and their rates are rising the fastest.
The ICR’s first report, released Feb. 2024, found that four types of cancer are mostly causing Iowa’s high cancer incidence: lung cancer, melanoma or skin cancer, breast cancer and prostate cancer.
“If you remove these four cancers from consideration, Iowa’s cancer incidence becomes more like the rest of the U.S., though still a bit higher,” the report stated.
Secondly, the ICR released their annual “Cancer in Iowa” report in March 2024, which featured data about alcohol as a risk factor to cancer. The report stated that, though cancer has several complex causes, “one modifiable risk factor where Iowans stand out, and that may be contributing to higher cancer rates, is alcohol consumption.”
This report also found that Iowa has the fourth-highest rate of alcohol-induced cancer cases in the country. Alcohol is a known carcinogen, the report explains, meaning it’s a substance that promotes cancer growth. More specifically, alcohol is known to increase risk of breast, liver, mouth, throat, esophagus, stomach and bowel cancers.
Despite these findings, Dr. Mary Charlton, director and principal investigator for the ICR, said in an interview that the report was not suggesting alcohol as the primary reason for Iowa’s abnormal cancer rates.
“Each year, we put out a report like this and each year we pick a different cancer type, maybe a different population, an exposure…this year it was alcohol,” she said.
Charlton said that ICR decided to focus on alcohol this year not only because it’s a common exposure among Iowans, but also because they’ve already featured other factors like smoking and race/ethnicity in previous reports.
Charlton said the ICR’s primary mission is to act as a “surveillance system” to state cancer data.
“At the Registry we only collect data on cancer cases,” Charlton said. “None of the risk factor data in this report was even from the ICR. It came from the CDC or the [Iowa Behavioral Risk Factor Surveillance] report.”
According to Charlton, one of the primary goals of the ICR is to compile data and encourage other investigators to use that data to research the “why” behind cancer trends. Another primary goal of the ICR is to educate people and hopefully help them prevent cancer.
“A study we found showed that only 40% of the general public knows that alcohol…is a carcinogen and has a link to cancer,” Charlton said. “So we thought there was a good public health message there and we could really build awareness around that.”
Charlton said it is especially difficult to make conclusions based on cancer data alone, seeing as Iowa’s four driving cancers are “very different cancers with very different risk factors and very different geographic patterns.”
For example, ICR’s February report found that the most common causes of lung cancer are tobacco use and radon exposure, while the main cause of melanoma is exposure to ultraviolet light. Breast and prostate cancer have a variety of external and genetic causes.
Charlton said the geographic patterns of these cancers are also complicated. Lung cancer is most prevalent in southern and rural parts of Iowa; breast cancer is most prevalent in urban areas; melanoma is most prevalent in northern parts of the state; and prostate cancer is most prevalent in western parts of the state.
Because many cancers take 20 to 30 years to form in the human body, Charlton said it is important to be collecting this risk factor data now “if we want to turn this around in the future.”
To read more about the ICR and other entities’ proposed strategies to address risk factors, visit the Iowa Cancer Plan website.
