Smoking and older age are the two most important risk factors for cancer, a new, large study shows.
The researchers also said doctors should look at excess body fat, family history and several other factors to help patients decide if they need additional screening and preventive interventions.
“Single cancer type-specific screening recommendations are based on risk factors for that specific type of cancer,” said lead study author Dr. Alpa Patel, senior vice president of population science at the American Cancer Society. “Our findings are encouraging as we are working to define subgroups in the general population who could benefit from enhanced cancer screening and prevention.”
To identify factors associated with more than a 2% risk of developing cancer in five years, researchers analyzed two American Cancer Society studies that included nearly 430,000 participants with no personal history of cancer. They were followed for up to five years.
Over that time, 15,226 cancers were diagnosed.
The relative risk of any cancer was strongest for current smokers compared with never smokers.
Over five years, absolute risk topped 2% for nearly everyone over age 50 and some younger people. Those included current or former smokers under 50 and long-term nonsmokers who were overweight or had a parent, sibling or child with a history of cancer.
In men, alcohol intake, family history, red meat consumption and physical inactivity were also associated with risk.
In women, risk was associated with BMI (a measure of body fat based on height and weight), type 2 diabetes, hysterectomy and tubal ligation, family history, high blood pressure and physical inactivity.
The absolute five-year risk was as high as 29% in men and 25% in women.
“As we consider the possibility that future tests may be able to identify several types of cancer, we need to begin understanding who is most at risk for developing any type of cancer,” Patel said. “These types of data are not widely available, but necessary to inform future screening options, such as blood-based multi-cancer early detection tests that could help save lives.”
The findings were published Aug. 3 in the journal Cancer.
The National Cancer Institute has more on risk factors for cancer.
SOURCE: American Cancer Society, news release, Aug. 3, 2022