A recent report on cancer shows that the U.S. is making significant progress in cancer prevention and treatment. Deaths from cancer have declined 23% overall since the high recorded in 1991. As a result, an estimated 1.7 million cancer deaths were prevented. The drop in cancer deaths was driven by three factors.
Early detection and prevention
Early detection and prevention were the leading cause of the decline in deaths for several types of cancers. For uterine cancer rates, for example, death rates plummeted over 80% in the 1930 to 2012 period because of the increasingly wide use of the Papanicolaou test (Pap test) to detect cervical cancer.
Mammograms and education for early detection of breast cancer caused an impressive 36% drop in deaths from breast cancer in women from the highest rate recorded in 1989. Death rates from both prostate and colorectal cancer have both been halved due to improved early detection methods and their implementation among the public.
The efficacy of detection methods is indicated by the relationship between colonoscopy, a recommended early detection and prevention method for colon cancer, and the reduced death rate and incidence of colorectal cancer. Both dropped roughly 3% annually from 2003 to 2012 in both sexes, likely because of the rapid rise in colonoscopy screening. Nineteen percent of adults 50 to 75 years old had colonoscopies in 2000. The figure had risen to 55% by 2013.
In people younger than 50, for whom colonoscopy screening is not recommended, by contrast, the death rates from colon cancer continued to rise, by 1.8% per year.
A reduction in tobacco use
Although many Americans still smoke, there has been a significant reduction in smoking over the decades in response to public health campaigns targeting tobacco. As a result, lung cancer deaths dropped 38% in men between 1990 and 2012, and declined 13% in women between 2002 and 2012.
Researchers estimate that the 1964 Surgeon General’s report on smoking and health has saved 8 million lives, one-third from cancer. The researchers highlighted campaigns against smoking itself and related campaigns, such as laws to curb smoking in public places.
Despite impressive gains, lung cancer is still one of the leading causes of cancer deaths. More than one-quarter of cancer deaths in the U.S. are caused by lung cancer.
Death rates from stomach cancer underwent a dramatic decrease from 1930 to 2012, primarily due to multiple healthier habits. In 1930s, stomach cancer caused 30% of cancer deaths among men and 20% among women. In 2012, it accounted for just 2% overall.
The reasons are not yet fully mapped, but researchers point to diets higher in fresh fruits and vegetables and lower salt consumption. Better public hygiene also likely resulted in lower incidences of infection with Helicobacter pylori, which is thought to be involved in stomach cancer.
Lower death rates and incidence expected going forward
Declining death rates will likely continue into the future as well. In the past 10 years, the death rate from cancer fell 1.8% annually for men and 1.4% annually for women. Dropping rates over the past 20 years have resulted from declining death rates from lung, breast, prostate, and colorectal cancers, the four most prevalent types in the U.S.
The incidence of cancer overall is also declining, driven by a 3.1% reduction in men and a flat incidence in women during the 2009 to 2012 period. The importance of early detection and prevention is shown in the drop for men: 50% of the decline is due to early detection of prostate cancer from methods like prostate-specific antigen (PSA) testing.
More research required
Despite impressive results, more work needs to be done. Death rates and incidence are falling, but more than 1.6 million new cancer cases will be diagnosed this year. More than half a million people will die.
Four types of cancer—lung, breast, colorectal, and prostate—cause 50% of all deaths each year. Despite massive strides in prevention and detection, cases continue to occur. More than 80% of lung cancer cases are caused by smoking. Breast cancer will be responsible for an estimated 29% of all cancers diagnosed in women.
Death rates from some types of cancer are still rising. Liver, pancreatic, and uterine corpus cancer fatalities continue to climb. In 21 states, cancer is now the leading cause of death. Deaths from heart disease are also dropping significantly but there is still work to be done.
Disparities remain among ethnic and age groups. African-American death rates from cancer are 15% above that of Caucasians, partly because cancers in this group are diagnosed at a later stage. Cancer among African American young people from 1 to 14 years old is the second most common cause of death.
The report illustrates the importance of early detection and prevention, cessation of tobacco use, and healthy habits. Increased research should be prioritized in the future.