Roughly 2 million Americans are expected to be diagnosed with cancer in 2024, while nearly 612,000 will die from the disease. Though there is not a sure-fire way to prevent ourselves from developing cancer, there are modifiable risk factors that can make us much more likely to face this diagnosis. A new study from the American Cancer Society shows that these factors may be responsible for hundreds of thousands of cases each year.

Research recently published in CA: A Cancer Journal for Clinicians looked into how many of the 1.78 million cancer cases diagnosed in Americans, and how many of the nearly 596,000 cancer deaths, in 2019 were attributable to potentially modifiable risk factors. Those include things like smoking, alcohol consumption, diet, excess body weight, and contracting seven different cancer-related viruses. In all, the research showed that 40% of cancer cases were linked to such factors, along with 44% of deaths. Researchers say this shows a need for widely available and equitable preventive initiatives to lower our national cancer burden.

Dr. Ahmedin Jemal, the study’s senior author and senior vice president of surveillance and health equity science at the American Cancer Society, says, “These findings show there is a continued need to increase equitable access to preventive health care and awareness about preventive measures. Effective vaccines are available for hepatitis B virus, that causes liver cancer and HPV, which can cause several cancer types, including cervical, other anogenital, and oropharyngeal cancers. Vaccination at the recommended time can substantially reduce the risk of chronic infection, and consequently, cancers associated with these viruses. HPV vaccination uptake in the United States is suboptimal.”

HPV, hepatitis B and C, human herpes virus-8, HIV, Epstein Barr, and Helicobacter pylori were among the high-risk viruses investigated in this study. Other modifiable risk factors included consumption of red and processed meats; low consumption of fruits, vegetables, dietary fiber, and dietary calcium; physical inactivity; and ultraviolet radiation. Though all have been found to cause cancer, smoking remained the biggest culprit.

The researchers found that smoking was linked with 19.3% of cancer cases and 28.5% of cancer deaths. The second biggest contributor was excess body weight, at 7.6% of cases and 7.3% of deaths. Alcohol consumption was linked with 5.4% of cases and 4.1% of deaths, while UV radiation and physical inactivity contributed to 4.6% and 3.1% of cases, respectively.

The study also looked at trends within 30 types of cancer. For 19 of them, at least 50% of cases were attributable to potentially modifiable risk factors. Lung cancer had the most such cases, followed by female breast, skin melanoma, and colorectal. The most deaths related to risk factors were found in lung, colorectal, liver, and esophageal cancers.

Additionally, more than 80% of cervical, melanoma of the skin, anus, larynx, lung and bronchus, pharynx, trachea, esophagus, and oral cavity cancers were linked with modifiable risk factors.

The researchers point to possible steps that can be taken to help lower the rates of these cancers.

Dr. Farhad Islami, the study’s lead author and senior scientific director of cancer disparity research at the American Cancer Society, says, “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. This finding underscores the importance of implementing comprehensive tobacco control policies in each state to promote smoking cessation, as well as heightened efforts to increase screening for early detection of lung cancer, when treatment could be more effective. Interventions to help maintain healthy body weight and diet can also substantially reduce the number of cancer cases and deaths in the country, especially given the increasing incidence of several cancer types associated with excess body weight, particularly in younger individuals.”

The American Cancer Society’s Cancer Action Network is advocating for policies across all levels of government to help people reduce their cancer risk. This includes making healthy diets and physically active lifestyles easier, along with the aforementioned tobacco control policies.

You can read more of the study here.