Cancer deaths have continued to drop steadily over the past few decades, with 1.7 million lives spared in large part by falling smoking rates, the American Cancer Society said Thursday.
But cancer remains a major killer. It has replaced heart disease as the No. 1 cause of death in 21 states and it will kill nearly 600,000 people this year, the organization said.
"We're gratified to see cancer death rates continuing to drop. But the fact that cancer is nonetheless becoming the top cause of death in many populations is a strong reminder that the fight is not over," Gary Reedy, chief executive officer of the American Cancer Society, said in a statement.
The drop's driven mostly by a reduction in smoking. The number of Americans who smoke has plummeted 20 percent on the past 10 years, from just under 21 percent in 2009 to 16.8 percent last year. But lung cancer is still the leading cancer killer, causing more than one in four cancer deaths.
Better prevention, screening and treatment have also saved lives, the American Cancer Society said in its annual look ahead. Nonetheless, more than 1.68 million Americans will be diagnosed with cancer in 2016, the group projected.
"Even as cancer remains the second leading cause of death nationwide, steep drops in deaths from heart disease have made cancer the leading cause of death in 21 states, and among adults ages 40 to 79, as well as among Hispanics and Asian/Pacific Islanders," the cancer society said.
Cancer and heart disease are neck and neck as a cause of death in the United States. In 2012, 24 percent of all deaths were from heart disease — 599,711 to be precise. And 582,623 deaths, or 23 percent of the total, were from cancer.
There's little change in the number of women being diagnosed with cancer, but about 3 percent fewer men are diagnosed every year, mostly because a common screening test for prostate cancer is no longer recommended. The test for prostate specific antigen, called the PSA test, was found to overdiagnose men with cancer that would never have harmed them.
"Over the past decade, cancer mortality dropped by 1.8 percent per year in men and 1.4 percent per year in women, driven by continued decreases in death rates for the four major cancer sites: lung, breast, prostate, and colon/rectum," the cancer society said in a statement.
"Death rates for female breast cancer have declined 36 percent from peak rates in 1989, while deaths from prostate and colorectal cancers have each dropped about 50 percent from their peak, a result of improvements in early detection and treatment."
Overall, cancer death rates fell 23 percent between 1991 and 2012.
"This 23 percent decline in cancer death rates is the result of decades of advancing our understanding and treatment of cancer," the American Society for Clinical Oncology, which represents cancer specialists, said in a statement.
"As a result of our nation's investment in cancer research, we have made tremendous progress in prevention, chemotherapy, surgery, radiation, immunotherapy and molecularly targeted treatments. Every cancer survivor is living proof of its progress."
The projections came out on the same day as new dietary guidelines from the federal government, and cancer groups, including the American Cancer Society, said they did not go far enough in helping advise Americans on the best ways to lower their risk of cancer.
"The science on the link between cancer and diet is extensive," said Dr. Richard Wender, the group's chief cancer control officer.
"By omitting specific diet recommendations, such as eating less red and processed meat, these guidelines miss a critical and significant opportunity to reduce suffering and death from cancer."
"For most Americans who do not use tobacco, the most important cancer risk factors that can be changed are body weight, diet and physical activity," it says.
"As an organization dedicated to cancer prevention, we are dismayed to see that the Dietary Guidelines have allowed lobbying efforts to supersede the scientific evidence when it comes to meat and cancer risk," Susan Higginbotham, vice president for research at the American Institute for Cancer Research.