New Cancer Estimates Provide 'Actionable Framework'

Zosia Chustecka

May 28, 2015

New estimates of the impact that cancer has had worldwide have been published from a new group using new methodology.

The new estimates come from a unique systematic Global Burden of Disease (GBD) analysis conducted by the Institute for Health Metrics and Evaluation (IHME). This GBD analysis for cancer is reported by a team of international researchers writing in a special communication published online May 28 in JAMA Oncology.

The GBD analysis estimates that worldwide, there were 14.9 million new cases of cancer, 8.2 million deaths, and 196.3 million years of a healthy life lost in 2013.

More than half of these were in developing countries (56% of new cancer cases, 62% of cancer deaths, and 69% of healthy life lost because of cancer).

The leading cause of cancer death worldwide for both men and women is lung cancer (together with cancer of the trachea and bronchus), with 1.6 million deaths in 2013.

For men, the leading cause of cancer incidence is prostate cancer (1.4 million cases worldwide in 2013); for women, it is breast cancer (1.8 million).

The IHME researchers note that cancer was the second leading cause of death in 2013 after cardiovascular disease, but they add that cancer burden is expected to increase in all countries because of population growth and aging.

Good assessments of the global burden of cancer is critical for improving cancer care, comment editorialists in an accompanying commentary.

Cause-specific cancer incidence and mortality statistics are essential to the development of appropriately targeted cancer plans, write Benjamin O. Anderson, MD, University of Washington, Seattle, and John Flanigan, MD, of the Center for Global Health, National Cancer Institute, Rockville, Maryland.

Such estimates are needed to "provide an actionable framework for health policy makers, particularly in low- and middle-income countries, where health resources are limited and competing health demands are great," they add.

How Does the New Methodology Compare ?

The editorialists note that these new cancer estimates are based on a methodology (GBD analysis) that was used for cancer for the first time. The researchers relied on cancer registries, vital records, verbal autopsy reports, and other sources for cause-of-death data.

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

However, a big question is how these new GBD estimates for cancer compare with those from the International Agency for Research on Cancer (IARC), which regularly publishes C15 and GLOBOCAN estimates. These are based on cancer registry methodology developed by IARC ― "heretofore considered by most to be the gold standard," the editorialists comment.

One potential flaw in the new GBD analysis is that it does not require an accurate tissue diagnosis, whereas this is fundamental to the cancer registry methodology used by the IACR. For this reason, the GBD approach developed by IHME seems unlikely to achieve the diagnostic precision of a pure cancer registry–based method, the editorialists comment.

But they add that "while GBD estimates of global cancer burden are unlikely to displace or replace CI5 and GLOBOCAN statistics, the profound benefits of GBD methodology should not be overlooked or underappreciated in the oncology community."

"In low- and middle-income countries, cancer patients may go uncounted in cancer registries, because they die of advanced disease before interfacing with the health care system. As a result, GBD can correctly identify cancer mortality in populations that CI5 and GLOBOCAN will miss. It may be that in some circumstances, GBD estimates may be more accurate in reflecting overall cancer," the editorialists write.

In some circumstances, GBD estimates may be more accurate in reflecting overall cancer. Dr Benjamin Anderson and Dr John Flanigan

"The oncology community would be unwise to interpret GLOBOCAN and GBD methodologies as competitive or mutually exclusive," they caution.

"The most important outcome for all of this work is to provide a framework for improving cancer care delivery," Dr Anderson and Dr Flanigan write.

"For the first time, GBD offers a powerful methodology that permits a direct comparison between cancer and other diseases and provides estimates for both disease prevalence and trends over time, which are essential in determining overall health burden to society," they note.

"This comparative perspective is critical for communicating with health care and finance ministers," they note.

The Institute for Health Metrics and Evaluation received funding from the Bill and Melinda Gates Foundation. Dr Anderson and Dr Flanigan report no relevant financial relationships.

JAMA Oncol. Published online May 28, 2015. Full article, Editorial


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: