Half of cancer deaths in US linked to ‘modifiable’ risk factors: Study

Four in 10 cancer cases and about half of cancer deaths among U.S. adults 30 years old and older in 2019 were linked to “modifiable” risk factors like smoking, drinking, poor diet and not getting vaccinated, according to a new study from the American Cancer Society.  

Lead author of the study Farhad Islami, senior scientific director of cancer disparity research at the American Cancer Society, explained that modifiable risk factors are typically behavioral.  

“When we say ‘potentially modifiable,’ those are the risk factors that we have the means and tools to change,” he told The Hill.

The study findings were published in the medical journal CA: A Cancer Journal for Clinicians, which is also the flagship journal of the American Cancer Society.  

Researchers at the American Cancer Society used data from the U.S. Centers for Disease Control and Prevention and the National Cancer Institute’s Surveillance, Epidemiology and End Results Program to determine the nation’s cancer rate and deaths in 2019.  

In addition, researchers determined the prevalence of risk factors by averaging three rounds of the National Health Interview Survey.  

What they found was 713,340 cancer cases, or about 40 percent of all cancer cases, and 262,120 cancer deaths for 30 types of cancer — including lung, breast and skin — could be attributed to risk factors linked to behavior.  

Cigarette smoking was the most common behavioral risk factor, contributing to 20 percent of all cancer cases and 30 percent of all cancer deaths, according to the study.  

“Despite considerable declines in smoking prevalence during the past few decades, the number of lung cancer deaths attributable to cigarette smoking in the United States is alarming,” Islami said.

Being overweight was the second most common modifiable risk factor, contributing to 7.6 percent of cancer cases and 7.3 percent of deaths, followed by drinking alcohol, which was linked to 5.4 percent of cancer cases and 4.1 percent of cancer deaths.  

When it comes to specific cancer type, one modifiable risk factor — an HPV infection — contributed to 100 percent of cervical cancer cases and deaths in the U.S. that year, the study found.  

The best way adults can protect themselves from cancers caused by an HPV infection is to get vaccinated against the virus. But HPV vaccination rates in the U.S. have stagnated at around 47 percent since 2019, one study found.

Other cancers that had high associations with modifiable risk factors were skin cancer, anal cancer, larynx, lung and oral cancer.  

More than 92 percent of anal cancer cases were linked to a modifiable risk factor like an infection; 94 percent of larynx cancer and nearly 90 percent of lung cancer cases were also linked to a modifiable risk factor, according to the study.