Washington: New cancer cases increased by 50 per cent in less developed countries over the last decade, even though globally the figure rose by 33 per cent, a new
study has found.
Researchers at the University of Washington in the US grouped countries based on their Socio-demographic Index (SDI) - a combined measure of education, income and fertility. New cancer cases in the highest SDI group - which includes countries like the US and Japan - grew by 36 per cent over the same period.
"The cancer divide is real and growing," said lead author Christina Fitzmaurice, assistant professor from the University of Washington. "The number of new cancer cases is climbing almost everywhere in the world, putting an increasing strain on even
the most advanced health systems," said Fitzmaurice. "However, the most rapid and troubling escalation can be seen in countries of lower development status, which can ill
afford it," Fitzmaurice added.
In addition, cancer mortality decreased in many nations over the past decade, but increased in more than 50 countries, most of which are in sub-Saharan Africa. These countries include Kenya, Tanzania, Niger, the Democratic Republic of Congo, Mali and Senegal, where health services needed to prevent, diagnose and treat cancer are often missing.
In 2015, there were 17.5 million new cancer cases worldwide and 8.7 million deaths. The disease burden of cancer remains heaviest for countries with the highest levels of
development, such as the US, the UK and Germany. Globally, 44 per cent of all new cancer cases and 34 per cent of all cancer deaths are in this highest development
group. New cases of cancer increased globally by 33 per cent between 2005 and 2015.
The most common forms of cancer globally are: breast cancer; tracheal, bronchus and lung (TBL) cancer; and colon and rectum cancer. TBL cancer and colon and rectum cancer top the list of those causing the greatest number of deaths, followed by
stomach and liver cancers. Breast cancer remains both the most common and deadliest
form of cancer for women, accounting for 523,000 deaths in 2015.
For men, prostate cancer caused the highest number of new cases, but TBL cancer was the number one killer overall, causing 1.2 million deaths globally. Diverse types of cancer also afflict countries very differently. For example, cervical cancer was ranked the 20th leading cause of death in the US in 2015; in neighbouring Mexico, however, cervical cancer was ranked significantly higher at number eight, with twice the mortality rate.
In South Africa, a lower-resource setting, cervical cancer was the second-leading cancer killer, claiming the lives of 5,400 women in 2015. The study was published in the journal JAMA Oncology.
