Global cancer cases 'still rising' - now 15 million a year

Recently, authors of a major report on worldwide numbers of cancer cases and deaths have provided "insights to disease burden that previously could only be loosely approximated" - finding that cancer represents a still growing proportion of all deaths, accounting for over 8 million in 2013.

"Complex and expensive treatments" - the rising cancer burden is a particular threat to developing nations "ill-equipped" to provide these options, the study concludes.

The JAMA Oncology global burden of cancer report is compiled by researchers collaborating from around the world, finding that worldwide in 2013, there were:

• Just under 15 million new cases of cancer
• Just over 8 million deaths from the disease
• About 196 million years of healthy life lost.

In spite of scientific advances, the overall results suggest a trend towards more cancer. In 1990, cancer deaths made up 12% of all mortality, but this proportion grew up until 2013, when it reached 15%.

There was a similarly growing morbidity. During the same period, the total amount of lost years of healthy life created by all cancers rose globally by 29%.

The researchers drew their data from a range of global sources - cancer registries, vital records registries, verbal autopsy reports and other sources of data on all causes of death.

The analysis covers 28 cancers and 188 countries. While cancer and vital records registries provided sparse data in many countries, an editorial commenting on the study says:

"These mathematically rigorous and elegant methods provide insights to disease burden that previously could only loosely be approximated."

These authors pick up on the "staggering" social impact of cancer in developing nations. Counted in healthy years lost, as measured by disability-adjusted life-years, this burden is created by "significant disability prior to death."

The study's findings on the burden in less developed countries are that these nations account for:

• Over half, 56% of new cancer cases
• Over 60% of cancer deaths
• Just over two-thirds, 69% of cancer-caused years of lost health, measured in disability-adjusted life-years.

The authors describe the global loss - in 2013 alone - of over 196 million disability-adjusted life-years as "astonishing."

"The data matters most when it causes us to act," they write, and in the less developed world, key decision makers and funding authorities "could feel compelled to allocate resources to support effective cancer treatment strategies that in the past went unfunded."

The editorial suggests that the focus needs to move away from the cancer control recommendations made by the UN and the World Health Organization (WHO), which "have been largely limited to prevention strategies and only superficially address cancer diagnosis and treatment strategies."

How the top 10 cancers compare

The new analysis of cancer figures was produced by dozens of researchers worldwide working together as the Global Burden of Disease Cancer Collaboration.

They ranked the following top 10 cancers by the number of new cases globally in 2013:

1. 1. Respiratory system cancers affecting the trachea, bronchus or lungs numbered an estimated 1.8 million new cases and 1.6 million deaths. The greatest loss of healthy life to disability from these cancers was in developing countries
2. 2.  Breast cancer saw 1.8 million new cases and 464,000 deaths, again with less developed countries taking up the greater proportion of total disability-adjusted life-years lost. Overall, one in every 18 women had breast cancer before the age of 79
3. 3.  Cancers of the colon and rectum numbered about 1.6 million new cases and 771,000 deaths
4. 4.  Prostate cancer: 1.4 million new cases and 293,000 deaths, with the disease meaning that men worldwide lost 4.8 million disability-adjusted life-years
5. 5.  Stomach cancer resulted in an estimated 984,000 new cases and 841,000 deaths, with more of the disabled years occurring in developing countries, and more men than women affected
6. 6.  Liver cancer: 792,000 news cases and 818,000 deaths. Some 86% of the disability-adjusted life-years lost were in developing countries, leaving 14% occurring in developed countries
7. 7.  Cervical cancer accounted for an estimated 485,000 new cases and 236,000 deaths worldwide in 2013, with 1 in 70 women developing cervical cancer at some point before reaching the age of 79 years
8. 8.  Non-Hodgkin lymphoma: 465,000 new cases and 226,000 deaths, with rates higher in men than women
9. 9.  Esophageal cancer resulted in about 442,000 new cases and 440,00 deaths
10. 10.  Leukemia presented 414,000 new cases and 265,000 deaths, with men making up more diagnoses than women.

A report in May showed that global spending on oncology medicines broke the $100 billion threshold in 2014.

References:

1.  The global burden of cancer 2013, Global Burden of Disease Cancer Collaboration, JAMA Oncology, doi: 10.1001/jamaoncol.2015.0735, published online 28 May 2015.
2.  Novel methods for measuring global cancer burden, implications for global cancer control, Benjamin Anderson and John Flanigan,JAMA Oncology, doi: 10.1001/jamaoncol.2015.1426, published online 28 May 2015.