Nearly Half of Cancers, Related Deaths Are Preventable

It is well-known that certain modifiable risk factors—including diet and smoking—can prevent the development of cancer. New data published by CA: A Cancer Journal of Clinicians suggests that nearly half of cancer cases and cancer-related deaths are preventable.

Based on current cancer rates, the authors estimated that 42% of cancer cases and 45% of cancer deaths are associated with modifiable risk factors.

In 2014 specifically, 659,640 out of 1.6 million cancer cases and 265,150 out of 587,521 cancer deaths were preventable, according to the study.

The authors calculated how much modifiable lifestyle behaviors contributed to the risk of 26 different cancers among adults 30 years of age and older. Risk factors included:

· smoking

· secondhand smoke

· excess weight

· alcohol consumption

· eating red meat

· not eating enough fruits, vegetable, fiber, and calcium

· a lack of exercise

· UV radiation

· infections with Helicobacter pylori, hepatitis B virus, hepatitis C virus, human herpes virus type 8, HIV, and human papillomavirus (HPV)

The authors first examined the prevalence of the factors and their relative risk to determine the prevalence of associated cancers. The researchers then applied the estimates to actual cancer diagnosis and mortality data.

The authors said that their study improves upon previous research since they included additional risk factors and up-to-date national data.

Although cancer mortality rate has dropped 25% since 1991, the American Cancer Society projects that more than 1.6 million cancers and 600,000 deaths will occur in 2017. The authors note their findings may help guide prevention efforts, according to the study.

Cigarette smoking caused the highest number of cancers and cancer-related deaths, at 19% and 29%, respectively, according to the study.

The study found that excess body weight was also a major risk factor and accounted for 7.8% of cancers and 29% of related deaths in 2014.

Exposure to UV radiation was linked to 5% of cancer cases and 1.5% of deaths, while physical activity played a role in 2.9% of cancers and 2.2% of deaths, according to the study.

When excess body weight, alcohol consumption, poor diet, and physical activity were grouped, the authors discovered that the risks were linked to 18% of cancers and 16% of deaths.

Additionally, the authors found these risk factors contributed to 100% of cervical cancers and Kaposi sarcoma and more than 75% of melanoma, anal, lung, larynx, and oral cavity cancers.

For 15 of the 26 cancer types examined, the proportion of cancer cases connected to modifiable risk factors exceeded 50%, according to the study.

The authors suggest that increased awareness and availability of prevention strategies—including taxing cigarettes and increasing HPV vaccination—could reduce the burden of preventable cancers.