Cancer deaths have declined by a fifth in the past two decades, according to data from the American Cancer Society (ACS).

The numbers mean that 1.5 million people who would have died of cancer didn’t.

Cancer death rates peaked in 1991, and have declined since then, led by the dwindling popularity of cigarette smoking, the ACS concluded based on data from the National Cancer Institute, the Centers for Disease Control and Prevention, and the National Center for Health Statistics.

Overall, cancer deaths declined more markedly among men, the data show. From 2007 to 2011, cancer death rates fell by an average of 1.8 percent per year among men and 1.4 percent among women.

Cancer diagnoses remained stable among women and declined 1.8 percent per year among men.

Lung cancer death rates among men declined by more than a third between 1990 and 2011, the last year for which data is available. Lung cancer continues to account for more than a quarter of all cancer deaths in the United States.

The other cancers that kill most often are colorectal in both men and women, prostate cancer in men, and breast cancer in women.

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Even with the declines, cancer accounted for almost one in four U.S. deaths in 2011, overshadowed only by heart disease. In addition, death rates for certain types of cancer continue to rise.

“The continuing drops we’re seeing in cancer mortality are reason to celebrate but not to stop,” said John Seffrin, Ph.D., CEO of the ACS.

Some Cancers Killing More People

Uterine cancer is killing more women, and melanoma and soft tissue cancers killing more men. Liver and pancreatic cancers are becoming deadlier to both sexes, according to NCI data.

Deaths from breast cancer are down more than a third while diagnoses are flat. However, more women are diagnosed with “carcinoma in situ,” a cancer doctors increasingly see as nonaggressive.

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Death rates for the most common men’s cancer, prostate cancer, by contrast, are down by half.

The gains were not evenly distributed across geographical regions. Cancer death rates have fallen in every state, but some states have seen significantly greater progress than others.

Southern states showed the smallest decline while Northeastern states showed the greatest. In Southern states, death rates fell by about 15 percent while in Maryland, New Jersey, Massachusetts, New York, and Delaware, death rates fell by 25 to 30 percent. These states are home to many elite cancer centers.

The ACS predicts more than half a million Americans will die of cancer in 2015. 

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