Rural areas see rising incidence of liver cancer
Although they represent only 15% of new cases of hepatocellular carcinoma (HCC), the most common type of liver cancer, HCC levels are rising faster among rural populations than in urban areas. Indeed, the rate of new cases is decreasing in urban communities. These results, previously presented at the Liver Meeting in 2020, were recently published in Clinical gastroenterology and hepatology.
Over time, chronic hepatitis B or hepatitis C, excessive alcohol consumption, fatty liver disease, and other causes of liver damage can lead to the development of liver cancer. In the past, HCC rates were higher in urban areas than in rural areas. With one in five Americans living in rural areas, it’s important to understand the spread of liver cancer in urban and rural areas.
Kali Zhou, MD, of Keck Medicine at the University of Southern California, and colleagues have studied liver cancer trends over the past 20 years in rural and urban communities in the United States. They used data from North American Association of Central Cancer Registries, with 93% coverage of the country. They included data on people over the age of 20 who were diagnosed with HCC between 1995 and 2016.
Of the 310,636 new cases of liver cancer reported, 85% were in urban areas and 15% in rural areas. During the study period, the average age-adjusted incidence rate of HCC was lower in rural communities than in urban areas.
While rural areas had a lower incidence of HCC, it increased at a higher rate than in urban areas. The average annual increase in the incidence of liver cancer in rural areas was 5.7%, compared to 3.9% in urban areas. In comparison, rates of lung, colorectal and breast cancer in rural populations have declined over the same period.
Among rural populations, men aged 60 to 69, African Americans, Native Americans and Alaska Natives, and those living in the South or in very poor areas had higher rates of cancer. liver.
From 2013 and 2014, the urban subgroups that experienced a notable decline in the incidence of HCC included men and women aged 40 to 59, Asians and Pacific Islanders, and people living in the western United States.
Between 1995 and 2016, the gap in HCC incidence rates between rural and urban areas widened. The incidence in urban communities began to decline in 2009, except for a peak in 2014, resulting in an increase of 118% from 1995 to 2016. In contrast, the proportion of new cases increased by 218% in rural areas during the same period. .
Because this study did not consider the causes and risks of liver cancer, more studies are needed to understand the determinants underlying these trends. One of the reasons could be more limited access to preventive care in rural areas. (People with hepatitis B or C who have progressed to cirrhosis should be screened regularly for HCC.) Researchers also suggest that higher rates of obesity and alcohol use in rural populations may contribute to this trend.
More research and investment in rural health care will help address the growing disparity in liver cancer incidence between urban and rural areas.
“HCC is an under-recognized critical public health problem affecting rural Americans,” Zhou said in a press release. “With the growing disparity between rural and urban areas in the incidence of HCC, such interventions are essential to better understand and address this growing inequality. “
Click here to read the study summary in Clinical gastroenterology and hepatology.
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