Cervical and breast cancer may soon be as great a cause of death as is maternal mortality in reproductive-aged women worldwide, given calculated trends from a newly released study.
The worldwide incidence of breast cancer has tripled annually since 1980, reaching 1.6 million cases in 2010; mortality from breast cancer has increased at an annual rate of 1.8%, reaching 425,000.
While the worldwide incidence of cervical cancer has increased at a slower annual rate of 0.6%, reaching more than 450,000 cases in 2010, annual mortality from cervical cancer has increased by 0.46%, reaching 200,000 cases in the same period.
"On the basis of trends recorded in this study, breast and cervical cancer are likely to soon approach maternal causes as a crucial cause of mortality in women of reproductive age in developing countries," wrote Dr. Mohammad H. Forouzanfar and his coinvestigators at the Institute for Health Metrics and Evaluation at the University of Washington, Seattle. The study was published online in the Lancet on Sept. 14 (doi:10.1016/S0140-6736[11]61351-2).
Twice as many breast cancer cases were recorded in developing countries among women aged 15-49 years as were in developed countries. New cases of cervical cancer occurred more often in developing countries (primarily in South and East Asia, Latin America, and Africa) across all age groups, while declining in high-income countries. In developing countries, there were 367,000 cases of breast cancer and 154,000 cases of cervical cancer among women aged 15-49 years. Three-quarters (76%) of cervical cancer cases occur in developing regions. In these areas of the world, 1.7 breast and cervical cancer deaths occur for every direct or indirect obstetric maternal death.
"Our findings suggest that breast and cervical cancer in low-income countries are major causes of death for women of these ages. The UN [United Nations] High-Level Meeting on Non-Communicable Diseases should raise policy awareness of the importance of the control of breast and cervical cancer, as should policy responses to improve reproductive health," the authors argued.
"Indeed, if the trends of the past 3 decades were to continue during the next 15 years, the ratio of maternal deaths to breast and cervical cancer deaths in developing countries in the reproductive age group will decrease from 2.3 to 1.3. In view of the potential for effective health system responses, greater efforts to reduce their disease burden are an important global health priority."
The researchers used information collected through population-based cancer registries, vital registration systems with medical certification of causes of death, and various subnational and national verbal autopsy studies. Their analysis comprised four components: database development, modeling MI ratios, estimation of trends in mortality by age, and estimation of trends in incidence. The investigators incorporated different data sources in a standardized approach to use all available information for every country.
In an accompanying commentary, epidemiologist Jan W. Coebergh described the new estimates of global breast and cervical cancer incidence and mortality as "staggering" (doi:10.1016/S0140-6736[11]61459-1).
"What would happen in response to another global problem causing morbidity and mortality of a similar magnitude? For example, the global death toll owing to breast and cervical cancer is the equivalent of six large jets crashing every day. Other forms of cancer kill three times this number of women daily, and the number of cancer deaths is even larger in men," wrote Dr. Coebergh, an epidemiologist in the department of public health at Erasmus University Medical Centre in Rotterdam.
"What will it take to instill a sense of urgency in our professional societies, academic institutions, governments, shareholders of biomedical companies, payers for health care, or society at large to end this tragic daily toll? Can we become as successful in prevention and cure of cancer as aeroplane manufacturers and the airline industry have been in improving safety in the past 80 years or so?"
Better cancer surveillance is crucial. "Improved cancer surveillance systems would also allow a detailed view of the quality of evolving clinical care, not only in different health settings and countries but also in respect of the various emerging and declining epidemics of individual cancers," he argued.
"Clearly broad actions are warranted, supported by global funds ... Nowadays, more and better research is demanded everywhere by representatives of the increasingly vocal cancer survivors’ groups. Let us listen to them more," he concluded.
The study was funded by Susan G. Komen for the Cure and the Bill and Melinda Gates Foundation.
The authors reported that they have no conflicts of interest. Dr. Coebergh reported that he has no conflicts of interest.