Distinct Racial and Ethnic Differences in Cancer Mortality Revealed in Published Study
Expanding on previous work highlighting disparities in cancer risk and mortality among diverse populations in Florida, a research team from Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine analyzed almost 250,000 people who died from cancer between 2008 and 2014 in another state with a diverse population: New York.
An article detailing the results of this new study, “Cancer Site-Specific Disparities in New York, Including the 1945-1965 Birth Cohort’s Impact on Liver Cancer Patterns,” was published on July 19 in the journal Cancer Epidemiology, Biomarkers & Prevention.
“The main focus of our study was to really understand what is going on in populations that have been understudied — particularly Caribbean blacks as opposed to American blacks, and within the Hispanic populations — and if what is going on in New York resembles what is going on in Florida,” said first author Paulo Pinheiro, M.D., M.Sc., Ph.D., a researcher at Sylvester and the Miller School’s Division of Epidemiology and Population Health Sciences.
The deeper dive into race and ethnicity subgroups aims to clarify previous work that tended to group all blacks or all Hispanics together. For example, prior research by Pinheiro and his team found essential differences between U.S.-born blacks and Caribbean blacks, as well as between Puerto Ricans and other Hispanic groups.
The investigators also focused on deaths attributable to liver cancer in a separate analysis. All major U.S. minority populations experience a higher incidence and mortality compared to non-Hispanic whites, and the rates are increasing.
The 244,238 cancer-related deaths in New York State Department of Health records showed considerable heterogeneity.
“At the extremes are U.S.-born blacks on one side and Asian and South American populations on the other; the former has the highest cancer mortality burden, the latter have very low rates relative to other analyzed groups,” the researchers noted.
Lung cancer was the leading cause of malignancy-related death for all men and women across the seven years studied, with the exception of Caribbean-born blacks and Central American Hispanics. In these two groups, lung cancer deaths were eclipsed by prostate cancer in men and breast cancer in women.
Risk Beyond Race
The investigators found some distinctions when evaluating American black and Caribbean black populations separately.
“They share a common race, but their outcomes are somewhat different,” Pinheiro said.
For example, the death rate among U.S.-born blacks was 269.5 per 100,000 for all cancers combined, compared to 140.7 per 100,000 for Caribbean-born blacks.
“Why are American blacks dying more from cancer than Caribbean blacks? There are disparities in access there, but U.S.-born blacks also get more cancers to start with,” Pinheiro said. U.S.-born blacks experience higher rates of cancers associated with modifiable risk factors — such as lung and colorectal cancers — compared to Caribbean blacks.
“This shows there is a lot of work to be done in terms of addressing the disparities that disproportionately affect American blacks,” he added.
The Heterogeneity of Hispanics
In contrast to the mortality rates in U.S.-born black populations, and despite similar socioeconomic factors, Hispanics generally have lower mortality risk from cancer compared to non-Hispanic whites.
“However, our study found all-cancer-combined mortality for Puerto Rican men to be similar to the majority non-Hispanic white population, albeit with considerable variation by specific cancer sites,” said Pinheiro.
Puerto Rican men had an all-cancers-combined death rate of 190.7 per 100,000, very close to the 193.3 per 100,000 rate among non-Hispanic whites. This is a novel finding, Pinheiro said.
Puerto Ricans might have a higher mortality rate for almost every cancer than other Hispanic populations because of factor factors such as obesity, smoking and excessive alcohol use.
“Over time, the Hispanic populations that acculturate to the American population are experiencing rates that approach those of whites,” Pinheiro said. “So far, we had not seen this for any group, but now in New York the rates are pretty much the same, although only among males. But this hides a lot of heterogeneity.”
The numbers are about the same but non-Hispanic whites experience more lung and other tobacco-related cancers, whereas Puerto Ricans tend toward more colorectal and liver cancers.
Special Focus on Liver Cancer
Pinheiro and colleagues also assessed liver cancer mortality, specifically as it relates to hepatitis C viral (HCV) infection. Chronic HCV infection has been a major driver of increases in numbers for liver cancer in the past decade. In addition, the Centers for Disease Control and Prevention Testing Recommendations for Hepatitis C Virus Infection target everyone born from 1945 to 1965, regardless of race or ethnicity.
The investigators modeled their sub-analysis after the CDC recommendations, assessing people born in that high-risk birth cohort, but again looking for differences by race and ethnicity.
“What we found was very interesting. The results really differ between gender, race and ethnicity, and they differ a lot,” Pinheiro said.
Liver cancer associated with HCV infection also disproportionately affects two populations: U.S.-born blacks and Puerto Rican men.
“Basically, American blacks and Puerto Ricans have this substantial increase in liver cancer rates in that age range where HCV infection is the main risk factor,” said Pinheiro.
Increased awareness of these liver cancer patterns is critical for clinicians making decisions with their patients about viral hepatitis testing, as well as for public health program planners, the researchers noted.
Pinheiro and colleagues also studied Asian populations in the overall study and sub-analysis. This group had a lower overall incidence for most cancers and some of the lowest mortality rates, except for liver and stomach cancers. In the sub-analysis, liver cancer was primarily driven by hepatitis B infection, so they were excluded from the hepatitis C-related assessment.
The study results suggest a change to the populations targeted by the National Viral Hepatitis Action Plan.
“Unfortunately, neither Hispanics in aggregate nor Puerto Ricans specifically are recognized as priority populations, which is especially concerning as effective HCV antiviral treatment that reduces liver cancer risk is now available,” the researchers wrote.
In addition, “Liver cancer mortality patterns seem less clear for women,” said Pinheiro. “Thus, future research must clarify the risk profile driving the excess liver cancer in minority women.”
He and his team plan to continue to monitor changes and priorities in cancer incidence and mortality over time.
“I work for Sylvester Comprehensive Cancer Center,” Pinheiro said, “and part of being a comprehensive cancer center is we monitor the patterns of cancer in our population.”
Co-authors from Sylvester and the Miller School included Raymond R. Balise, Ph.D., David J. Lee, Ph.D., and Erin Kobetz, Ph.D., M.P.H.