Heart disease and stroke have dropped to second place — behind cancer — among the leading causes of death in 12 Western European countries, a new study reports.

Worldwide, though, cardiovascular disease remains the leading cause of death, killing an estimated 17 million people each year, according to the World Health Organization (WHO).

In the United States, progress has been made in treating both cancer and heart disease, with the two conditions remaining the top two killers in the country.

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Cancer, heart disease in the U.S.

In the United States, overall deaths from heart disease or stroke still outnumber cancer, killing almost 750,000 people in 2014.

That same year, almost 592,000 people died from cancer.

Among people aged 40 to 79, though, cancer is the leading cause of death, if heart disease and stroke are looked at separately.

Cancer mortality outnumbers those of heart disease in 21 states, largely due to improvements in the prevention and treatment of cardiovascular conditions.

The rate of heart disease deaths has fallen sharply since the 1950s.

Part of this decline is due to targeting the risk factors for cardiovascular disease — high blood pressure, diabetes, high cholesterol, and smoking.

“Treatment of those has probably resulted in less severe heart attacks and strokes, and therefore fewer deaths from those conditions,” Dr. Nisha Parikh, a cardiologist and assistant professor of medicine at the University of California, San Francisco, told Healthline.

Risk factors can be controlled with lifestyle changes like eating healthier and exercising more. But new medications — such as statins for high cholesterol — have also played a big role in recent years.

In addition, better treatments exist now than 60 years ago.

“In terms of heart attacks, in the 1950s and 60s, we would have just watched somebody and treated them with medicines that may or may not have really helped their outcome,” said Parikh.

Today when someone shows up at the hospital in the middle of a heart attack or stroke, doctors have more medication at their disposal, along with surgical procedures like cardiac catheterization.

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Improvements for some cancers

Cancer is a more complicated story.

Overall cancer death rates increased before 1990 and then started to fall for both men and women.

“The largest percent decline in mortality has occurred for prostate, Hodgkin lymphoma, lung and stomach for men; and Hodgkin lymphoma, non-Hodgkin lymphoma, and larynx and colon or rectum cancers for women,” Kathy Cronin, Ph.D., M.P.H., the deputy associate director of the Surveillance Research Program in the Division of Cancer Control and Population Sciences at the National Cancer Institute, told Healthline.

Some cancers, though, have been losing ground.

“Although there has been a steady decline overall, there are some sites that are experiencing an increase in mortality rates,” said Cronin.

Between 2003 and 2012, death rates among men increased for liver, heart, and pancreas cancers.

For women, death rates increased during that time for cancers of the liver, uterus, and pancreas.

But even when progress is made in preventing and treating cancer, certain groups lag behind.

The overall rate of death from prostate cancer has been declining since the early 1990s, but “in black men, their mortality rates remain twice as high as those in any other group,” Kim D. Miller, M.P.H., an epidemiologist at the American Cancer Society, told Healthline.

Likewise, the incidence of lung cancer among men has been declining since the mid-1980s.

But for women, lung cancer increased through 2007 and then started to drop.

“Women took up smoking in large numbers later than men and they were slower to quit,” said Miller. “Because lung cancer is such a fatal cancer, we see the same thing with death rates. We see that rates began declining earlier in men than in women.”

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Long-term outlook mixed

Four cancers — prostate, breast, colon, and lung — make up about half of the cases diagnosed each year. These will shape the future of cancer in the United States.

“Although there are improvements in incidence, mortality, and survival resulting from reduction in risk factors — such as tobacco use — early detection, and treatment,” said Cronin, “[these cancers] will continue to play a dominant role in the overall incidence and mortality trends.”

Early detection, or screening, has the potential to catch cancers early, when they are easier to treat.

This has been the case with colorectal cancer — which has been declining in both incidence and death rates.

“The declines have actually become much larger in recent years,” said Miller. “This is largely thought to be due to the widespread uptake of screening, which for colorectal cancer doesn’t only detect the cancer early, but it also can prevent cancer entirely.”

In spite of the gains made in preventing and treating heart disease and cancer, the future is not all rosy.

The obesity epidemic will contribute to both diseases for years to come, even as other risk factors like smoking are on the decline.

Being obese increases not only the risk of heart disease and stroke, but also other risk factors for those conditions.

“Along with obesity comes high blood pressure, diabetes, and high cholesterol,” said Parikh. “Going forward that’s going to be our biggest challenge, at an individual level and also structurally and societally.”

Obesity has also been linked to an increased risk of certain cancers, including colorectal, endometrial, and liver cancer.

It may be years before the full effect of obesity on cancer is seen.

“Even though we’re seeing potential leveling off of the obesity epidemic in adults, it’s still concerning because we’re not seeing declines in obesity yet,” said Miller. “So it has very important implications for the future cancer burden.”

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