The global burden of multiple myeloma has increased uniformly in the last 30 years, but the incidence of myeloma is highly variable among different countries, according to the results of a study published in JAMA Oncology.
For example, although more common in high sociodemographic index countries, increases in incidence were much greater from 1990 to 2016 in middle and low-middle sociodemographic index (SDI) countries.
“Approval for effective drugs and stem cell transplantation options are lacking in many low-SDI countries,” wrote lead author Andrew J. Cowan, MD, of the University of Washington, Seattle, and colleagues. “Collaborative global efforts are needed to ensure that every patient with myeloma is being diagnosed and has access to effective treatment.”
To calculate these trends, Cowan and colleagues collected data on incidence, mortality, and disability-adjusted life-year (DALY) estimates from a variety of sources, including vital registration systems, cancer registries, drug availability, and survey data for stem cell transplant rates. They also looked at the approval of lenalidomide and bortezomib worldwide.
In 2016, there were about 130,000 cases of myeloma, translating to an age-standardized incidence rate of 2.1 per 100,000 persons. Multiple myeloma caused 98,437 deaths globally, with an age-standardized incidence ratio of 1.5 per 100,000 persons.
That means from 1990 to 2016, incident cases of myeloma increased by 126% globally and deaths increased 94%. The researchers estimated that population growth contributed to about 40% of this increase, an aging world population contributed about 52.9%, and a rise in age-specific incidence rates contributed about 32.6%.
Australasia, high-income North America, and Western Europe had the highest age-standardized incidence ratio of myeloma. The United States had the most incident cases and deaths from myeloma.
“At least some of the differences in incidence may be due to lack of diagnostic abilities in lower SDI countries compared with high SDI countries and do not necessarily reflect differences in disease biology,” the researchers wrote.
Looking at treatment availability, the researchers found that stem-cell transplant is routinely available in high-income countries, but availability was lacking in sub-Saharan Africa and parts of the Middle East.
In 2016, lenalidomide and bortezomib had been approved in 73 of 103 countries, with neither drug approved in most countries in sub-Saharan Africa and some countries in Central Asia. The researchers acknowledged that assessment of “true availability”—as determined by cost, affordability, and reimbursements—could not be accomplished.
“Nonetheless, two drugs that are now considered standard of care, lenalidomide and bortezomib, have not been approved in some African and Middle Eastern countries, and it is notable that there are no stem cell transplant centers in sub-Saharan Africa, with the exception of South Africa,” they wrote. “Thus, on a global level there are marked discrepancies in the availability of effective therapies.”