The cancer death rate in the United States has dropped 25 percent from a peak in 1991, a decline of around 2.1 million deaths, new research released on Thursday shows.
The dramatic change over the last quarter-century is chiefly the result of a steady decline in smoking combined with medical advances in early tumor detection and treatment, according to an annual report by the American Cancer Society (ACS).
Patients suffering from four types of cancer accounted for the largest declines in mortality.
Lung cancer deaths among men plummeted by 43 percent between 1990 and 2014 and 17 percent among women between 2002 and 2014.
The breast cancer mortality rate for women decreased by 38 percent between 1989 and 2014.
The drop is even more dramatic among men suffering from prostate cancer — 51 percent between 1993 and 2014 — and in colon cancer deaths among both sexes, which plunged 51 percent between 1976 and 2014.
Some 1.68 million new cases of cancer will emerge in the United States this year, the report predicts, along with 600,000 deaths from the disease.
“The continuing drops in the cancer death rate are a powerful sign of the potential we have to reduce cancer's deadly toll,” ACS chief medical officer Otis W. Brawley said.
The research was published in CA: A Journal for Clinicians.
– Gender disparities –
Over the past decade, the incidence of cancer has remained stable among women and declined among men by almost two percent a year.
The mortality rate from the disease has dropped by around 1.5 percent annually among both sexes.
But the report finds significant disparities in incidence and mortality between genders.
In all forms, the frequency of cancer is 20 percent greater among men and the mortality rate 40 percent higher.
That difference is mainly due to the risk factors affecting each sex.
Liver cancer, an extremely fatal form of the disease, is three times more common in men than women. That partly reflects a higher rate of Hepatitis C infection among men — often associated with unprotected sex — and the fact that men tend to consume tobacco and cigarettes in higher rates.
The largest disparities between the two sexes are for cancers of the esophagus, larynx and bladder, for which incidence and mortality are around four times greater in men.
Melanoma, an aggressive skin cancer, is also 60 percent more frequent among men and the death rate twice as high.
– Racial differences decline –
At the same time, racial disparities in cancer mortality have declined.
The higher death rate among African-American men compared to white men has declined by almost half in the past quarter-century, from 47 percent in 1990 to 21 percent in 2014, the report says.
The disparity also fell among black women compared to white women from a peak of 20 percent in 1998 to 13 percent in 2014.
Although cancer death rates in general remained 15 percent higher among African Americans than among white people in 2014, growing access to health care and prevention contributed significantly to the improvement, the report speculates.
It cites the Affordable Care Act, President Barack Obama's landmark health care reform enacted in 2010, which extended medical insurance to around 20 million previously uninsured Americans.
The number of African Americans without insurance declined by half from 2010 to 2015, dropping from 21 percent to 11 percent. Among Hispanics — another socially disadvantaged group — the rate fell from 31 percent to 16 percent.
Maintaining the overall drop in mortality rates “will require more clinical and basic research to improve early detection and treatment, as well as creative new strategies to increase healthy behaviors nationwide,” Brawley said.
“Finally, we need to consistently apply existing knowledge in cancer control across all segments of the population, particularly to disadvantaged groups.”