Nearly half of all cancer deaths are preventable, study finds: 7 key takeaways

Physicians have long said that the risk of cancer can be reduced based on lifestyle choices, but researchers have published new data suggesting that many cancer deaths could be avoided.

About half of all cancer deaths and 40% of all cancer cases can be avoided by adjusting behavior, an American Cancer Society study finds.

Nearly half of all cancer deaths are preventable, and about 40% of all cancer cases are associated with behaviors that can be modified, according to research published this week by the American Cancer Society. The findings are published in CA: A Cancer Journal for Clinicians.

In 19 of 30 cancers studied, more than half of all cancers and cancer deaths were tied to preventable risk factors, researchers found. They estimated that modifiable risk factors, including but not limited to smoking and excess weight, could be tied to more than 713,000 cancer cases and more than 262,000 cancer deaths.

The study has gained considerable attention and points to the need for providers to help patients engage in healthier habits that can reduce their chances of developing cancer.

Here are seven key takeaways.

• Read more: More younger adults are being diagnosed with cancer

1. ‘Alarming’ deaths tied to smoking

Cancer deaths have declined over the last few decades as fewer people smoke cigarettes, but smoking remains the highest risk factor in cancer cases and deaths, researchers found.

Cigarette smoking ranked as the leading risk factor in more than a quarter of cancer deaths (28.5%), and 19.3% of all cancer cases, researchers found.

Dr. Farhad Islami, lead author of the report and senior scientific director of cancer disparity research at the American Cancer Society, said the study illustrates the importance of early screenings for lung cancer. He also pointed to the need for strong tobacco control policies nationwide.

“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 in a news release accompanying the study.

• Read more: How the American Cancer Society hopes to include outcomes for Black women

2. Excess weight raises risk

Researchers identified excess body weight as the second leading risk factor in cancer cases (7.6%) and cancer deaths (7.3%). Excess weight accounted for more than half of all cancers of the corpus uteri, or endometrial cancers, and more than one-third of gallbladder, esophageal, liver, and kidney cancers, researchers found.

In men, excess weight was the third highest factor in cancer cases, but it was the second highest in women, according to the study.

Women with excess weight are more likely to develop breast cancer. Researchers said breast cancers ranked second among cancers tied to excess weight, trailing only endometrial cancers.

• Read more: Black patients have higher mortality in most cancers and gaps persist at higher incomes

3. Drinking can be a factor

Alcohol consumption ranked as the third leading avoidable risk factor in cancer cases (5.4%) and cancer fatalities (4.1%), according to the study.

There is a bit of a difference in genders, with alcohol consumption being the third largest contributor in cancer cases among women and the fourth highest in men.

Female breast cancer had the highest number of attributable cases (44,180 cases). Colorectal cancer cases followed, in both men (13,850) and women (4,630).

4. Diet matters

Dietary factors are linked with some cancers, and men appear to be at greater risk, according to the study.

Researchers estimated that 4.9% of cancer cases in men were linked to dietary factors, compared to 3.4% of cancers among women.

In some cancers, diet and nutrition play a higher role, researchers say. In colorectal cancer, eating processed meats is linked to 12.8% of cases, while low fiber (10.%) and consuming red meat (7.3%) were also identified as factors.

Researchers also pointed to the value of eating plenty of fruits and vegetables.

“Among dietary factors, low fruit and vegetable consumption contributed to most cancer cases and deaths,” the researchers wrote.

5. Physical inactivity

Researchers said their analysis reflects new insights on the potential of inactivity in developing cancer. Researchers say 3% of cancer cases and deaths can be linked to inactivity.

For women, physical inactivity was identified as the fourth largest contributor to total cancer cases, while it ranked as the sixth highest among men.

The largest number of attributable cases tied to inactivity were breast cancer and colon cancer.

6. Combined factors

Some individuals would check a number of boxes, including those who regularly drink alcohol, eat a great deal of processed foods, and don’t get much exercise. Those individuals face greater risks of cancer, researchers say.

The combination of excess weight, alcohol consumption, dietary factors and inactivity contributed to the second highest proportion of cancer deaths in both men and women.

The combo accounted for a quarter of all cancer deaths in women and almost 1 in 5 cancer deaths among men. Those four factors also are linked to the highest proportion of all cancer cases in women and was second only to smoking in men.

“These findings suggest that maintaining a healthy body weight, cessation or limiting alcohol consumption (for those who drink), consuming a healthy diet, and being physically active can substantially reduce the number of cancer cases and deaths in the United States,” the researchers wrote.

7. Totally preventable cancer

Researchers pointed to all cervical cancer cases as preventable, due to availability of HPV vaccination and screenings.

At the same time, researchers note too many aren’t taking advantage. Only 73% of women between the ages of 21 and 65 are up to date on cervical cancer screening and vaccination, and the number is lower for girls 13-17 (64%).