Analysis of cancer mortality trends reveals disparities for Hispanic populations

While cancer mortality rates in the U.S. have decreased, cancer remains the leading cause of death among Hispanic individuals, who generally having lower cancer incidence compared to non-Hispanic white individuals. A new study by investigators from the Mass General Cancer Center, a member of the Mass General Brigham healthcare system, evaluated cancer mortality trends and identified disparities for Hispanic men and women by age group, cancer type, and United States region over two decades. They found that while cancer mortality rates overall declined, rates of liver cancer death among Hispanic men and women and rates of pancreatic and uterine cancer deaths among women increased from 1999 to 2020. Their results are published in JAMA Oncology.

“Despite the great strides in cancer screening, education and treatment advances, there are  populations in the U.S. that haven't benefited from these improvements equally,” said senior and corresponding author Sophia C. Kamran, MD, of the Department of Radiation Oncology at the Mass General Cancer Center. “Cancer incidence is fairly low among Hispanic populations, but it the leading cause of death. My team wanted to know which cancers might be driving this.”

Kamran and colleagues used data from the Center for Disease Control and Prevention’s public Wide-ranging ONline Data for Epidemiologic Research (WONDER) database to answer this question. The database captures the cause of every death in the U.S. from death certificates and is maintained by the National Center for Health Statistics. Data are disaggregated by sex, age of death, place of death, and more.

The researchers analyzed 690,677 cancer deaths among Hispanic individuals and found that, overall, cancer mortality decreased for Hispanic individuals from 1999 to 2020, with a larger decrease among men compared to women. One exception was an increase in cancer mortality rates among Hispanic men between the ages of 25 to 34 years. Upon further analysis, the team discovered that rates of colorectal and testicular cancer deaths were especially high for men in this group.

“This finding was pretty striking and may be driving the increase in overall cancer specific mortality in this particular age group,” Kamran said. “There could be a lack of awareness, education, and screening since there is a stigma associated with testicular cancer. And we know colorectal cancer mortality is increasing among younger populations in general.”

The team found additional cancer types where mortality also increased across all age groups from 1999 to 2020: liver cancer among men and liver, pancreatic, and uterine cancer among women. Liver cancer mortality rate also increased significantly in the West for Hispanic men and women compared to other regions of the U.S.

The authors have some hypotheses that may help explain these disparities: Hispanic immigrants may have less access to health care and insurance coverage, and Hispanic patients are more likely to be diagnosed at advanced cancer stages, which could drive poor survival. In addition, Hispanic patients are often not well-represented in cancer clinical trials.

Researchers did see substantially reduced lung cancer mortality rates among both Hispanic men and women.

“This might be pointing to the fact that there’s been a lot of education about smoking cessation and improvement in screening and treatment for this cancer,” Kamran said. “That was very encouraging.”

Equipped with this information about cancer mortality trends, researchers, educators, and policymakers can identify populations and cancer types that require additional efforts to reverse increasing mortality trends.

Limitations of the study included potential for the WONDER database misclassifying cause of death. The study also does not include undocumented populations nor account for migration or changes in zip code over time. Further, data about stage of cancer, previous treatments, insurance status, education, employment, or language were not available so the analysis could not account for these factors that might affect cancer mortality rate.

More granular data collection and analysis could strengthen investigations and allow researchers to replicate results in similar studies for specific disaggregated Hispanic subpopulations. Still, current findings underscore unique disparities that exist for Hispanic individuals.

“Clearly, the Hispanic population can't just be lumped together with all other U.S. cancer patients,” Kamran said. “We have to think a little bit differently and target specific cancer research, education, and treatments toward this population, so we are caring for these patients as best we can.”