Cancer mortality rates down 20 per cent in US: study

The mortality rate due to cancer was on the decline nationwide, but certain regions and pockets throughout the country had shown worsening mortality rates from the deadly malignancy, according to the first-ever county-by-county analysis of cancer deaths across the US.

The death rate attributed to various types of cancer declined 20 per cent between 1980 and 2014, according to research published yesterday in the Journal of the American Medical Association. During the period, the number of cancer deaths per 100,000 Americans fell from 240.2 in 1980 to 192 in 2014.

Cancer, the No 2 cause of death in the US, has long been tracked by health officials, but existing databases had largely measured such statistics on state or national levels.

According to the report, death rate from cancer was now 25 per cent lower than it was 25 years ago.

That could hide cancer trends that crossed state borders, or that could be seen in geographically limited ''hot spots''. It could also obscure associations with environmental exposures, ethnic settlement patterns or health behaviours like poor diet that might be unique to a single county or shared only with its near neighbours.

The new tally of close to 20 million cancer deaths over 35 years offered a new detailed view of cancer's toll and also gave county officials who designed and carried out most of the nation's public health campaigns, the data they needed to detect or respond to trends within the populations for which they were responsible,  according to commentators.

The study found that in parts of the US that were relatively poor, and had higher rates of obesity and smoking, cancer death rates rose nearly 50 per cent, while wealthier pockets of the country saw death rates fall by nearly half.

Better screening and treatment had contributed to  the improvement across the nation as a whole - but the study underscored that not all US citizens had benefited from these advances.

"We are going in the wrong direction," said Ali Mokdad, the study's lead author and a professor at the University of Washington's Institute for Health Metrics and Evaluation, Fox News reported. "We should be going forward, not backward."