A Diverse Set of Discoveries

Like many different forms of cancer, liver cancer is of significant interest to researchers in light of an aging population and increasing cancer rates across society. This is particularly true for hepatocellular carcinoma (HCC), the most common form of liver cancer, especially as liver cancer mortality increases. However, rates of this cancer vary depending on patients’ ethnic background.

A team of researchers from the University of Miami School of Medicine have aimed to establish the reasons behind this ethnicity discrepancy, hoping to pinpoint the specific causes of liver cancer among different racial and ethnic groups, including Black, Hispanic, Asians, and Haitian demographics (1).

“By analyzing trends, we can determine which causes are on the rise and which are diminishing over time,” says corresponding author Paulo S. Pinheiro. “It's crucial to strategize how we can expedite the decline of increasing causes and accelerate the trend of the decreasing ones, using the prevention means we have at our disposal.”

Pinheiro explains that trends in liver cancer based on ethnic groups have long puzzled researchers. Unlike cancers such as breast, colorectal, and pancreatic cancer, researchers have a much easier time in determining the cause – so much so that cause can be established in 90 percent of patients.

“Discovering differences in etiology can help detect racial-ethnic groups that have been overlooked in terms of liver cancer risk,” says Pinheiro. “Liver cancer etiology does not really impact treatment, as it is treated the same way regardless of cause, but it does impact prevention.”

The team’s study used population-based analysis on all of Florida’s liver cancer cases between 2010 and 2018 – more than 14,000 in total – which is a methodology yet to be seen elsewhere in the US.

The team’s findings include a notable cause among Hispanics is fatty liver disease and alcohol consumption. However, when it comes to causes of liver cancer that are generally decreasing – such as hepatitis C – they are more common in US-born white and Black populations. An overall speedy increase in HCC caused by fatty liver disease and alcohol is present in men and women from all backgrounds, with possible exception for Asians, the paper explains.

According to Pinheiro, the researchers were surprised to see the amount of variation not just between groups, but within them too. “Simply put, all Black people are not the same, all Hispanics are not the same, and all Asians are not the same,” he explains.

Some unexpected findings from the paper include the threefold difference between Peutro Rican and Cuban males, despite them both being Caribbean populations. The fact that the Puerto Rican cohort has higher rates demonstrates that labeling patients under a single ethnic category can be misleading.

Similarly, there were some similarities shared between groups. For example, Filipino people have higher rates of fatty liver-related liver cancer, which displays similarities with Hispanic groups. Additionally, Hepatitis B viral infection – known as a primary cause among Asian populations – is also common in Haitian Black males.

It’s hoped this research could lead to greater screening for hepatitis C and B viral infection for all adults in Florida. Another important step forward would be to expand this surveillance of etiology-specific liver cancer in years after 2018 both state-wide and across the US. 

As for the impact on laboratory professionals, Pinheiro explains that further work needs to focus on the genetic characteristics of liver cancer tumors. “This could include immunohistochemistry tests on HCC, which could potentially lead to the identification of therapeutic pathways,” he says. “However, HCC is normally diagnosed via CT scanning and MRI routine and liver biopsies aren't commonly used to diagnose HCC due to their side effects and discomfort. This limits our understanding of HCC and research possibilities.”