In its annual report on cancer rates and deaths, the American Cancer Society (ACS) reports that deaths from cancer have dropped by 22% over the past 20 years, saving 1.5 million lives.
The review, published in the journal CA: A Cancer Journal for Clinicians, included data from 2007 to 2011 and found that decreases in deaths from four major cancers—lung, breast, prostate and colon—are driving much of the improvement. More widespread screening, which is leading to early detection and treatment, is helping to find more cancers and manage them before they become fatal, says Rebecca Siegel, director of surveillance information for the ACS and lead author of the study. Deaths from prostate and colon cancers have dropped by almost half since their peak several years ago, and lung and breast cancer have declined by about a third from their highest rates.
But the data also show a disturbing trend of slower progress in southern states. On average, death rates in the lower part of the U.S. have declined by about 15%, compared to drops of 25% to 30% in Delaware, Maryland, Massachusetts and New York.
The reason for the smaller declines, says Siegel, may have a lot to do with higher smoking rates in states like South Carolina and Kentucky, as well as more obesity and greater disparities in socioeconomic status. People with lower incomes are less likely to have access to cancer screening and treatment programs. “We are seeing large differences by state,” she says. “We need to reach everyone in the population with advances in early detection and improvements in treatment because they just aren’t equally disseminated. That’s why you see differences; it’s not just biology.”
The improvements in northeastern states shows that it’s possible. “If we could apply everything we know to everyone in the U.S., there would be enormous gains from just that,” says Siegel.
That’s especially important as the population continues to age. Since cancer is generally a disease of aging, the absolute number of cancer diagnoses, and potentially deaths, could increase. (In 2015, an estimated 589,430 Americans will die of cancer.) But expanding screening programs and ensuring that more people have access to them could help keep cancer rates and deaths trending downward.