According to new research released by the American Cancer Society (ACS), about 40 percent of new cancer cases and nearly half of all deaths among U.S. adults age 30 and older are attributable to preventable risk factors.
Arif Kamal, Chief Patient Officer at ACS, said, “People can actually make changes in their day-to-day lifestyle that will reduce their risk of cancer.”
Smoking : top cancer risk factor
The study found that smoking is by far the main risk factor, contributing to nearly one-fifth of cancer cases and nearly one-third of deaths in human society. Other major risk factors included excess weight, alcohol consumption, lack of exercise, diet and infections such as HPV.
Overall, the researchers analyzed 18 modifiable risk factors for 30 cancers. According to the study, in 2019, these lifestyle factors were associated with more than 700,000 new cancer cases and more than 262,000 deaths.
Cancer grows because there is DNA damage or the cancer cells have a fuel source, Kamal said. Other factors – such as genetics or environmental factors – also contribute to these biological conditions, but the modifiable risks carry more weight than any other known factor. For example, exposure to sunlight damages DNA and leads to skin cancer, while fat cells produce hormones that cause certain cancers.
Kamal says: “With cancer, you often feel like you have no control. People think about bad luck or bad genetics, but people need to have a sense of control and agency.”
This new study shows that some cancers are more preventable than others. In 19 of the 30 types of cancer evaluated, more than half of the new cases were attributable to modifiable risk factors.
There were 10 types of cancer where at least 80 percent of new cases could be attributed to modifiable risk factors. This includes melanoma, where more than 90 percent of new cases are linked to ultraviolet radiation. And almost all cases of cervical cancer are linked to HPV infection, the latter of which can be prevented by vaccine.
Lung cancer has the highest number of cases attributable to variable risk factors – more than 104,000 in men and more than 97,000 in women – the vast majority of which are related to smoking.
Obesity ranks the second
Being overweight is the second most common cancer-causing factor after smoking, with about 5 percent of new cases in men and nearly 11 percent of new cases in women linked to being overweight. The new study found that more than one-third of deaths from endometrial, gallbladder, esophageal, liver and kidney cancers are linked to being overweight.
Another recent study found that taking popular diabetes and weight-loss pills (such as Ozempic and Wegovy) reduced the risk of cancer.
Marcus Plescia, chief medical officer of the Association of State and Territorial Health Officials, said, “In some ways, obesity is becoming as harmful to people as smoking.” He was not involved in this new study, but has previous experience working in cancer prevention.
Interventions on “core behavioral risk factors” – such as smoking cessation, healthy eating, and exercise – can “make a huge difference in the incidence and outcome of chronic disease,” says Plescia. make a huge difference in the incidence and outcomes of chronic disease.” He noted that cancer is a chronic disease, just like heart disease or diabetes.
With the incidence of early-onset cancers on the rise in the U.S., experts say it’s especially important to adopt healthy habits as early as possible. Once you start smoking or gain weight, it’s much harder to quit or lose weight.
But Plescia said, “It’s never too late to make those changes. Changing (health behaviors) later in life can have a profound effect.”
