Increase in liver cancer in rural United States
The incidence of hepatocellular carcinoma – the most common form of liver cancer – has declined in urban areas but has steadily increased in rural areas of the United States over the past two decades, according to recently released data.
The results – which were printed in the journal Cancer – show a growing disparity between the two patient populations and underline the need for further research on the causes of this increase, according to the authors of the study.
Lead author of the study, Dr Kali Zhou, assistant professor of clinical medicine at the Keck School of Medicine at the University of Southern California, said in an interview with CUREÂ® that this study primarily focused on rate of liver cancer due to its poorer prognosis. compared to other cancers.
âRaising awareness is really important because, above all, prevention followed by early diagnosis is crucial to identifying cancer at an early stage and saving lives,â she said.
The results of the study showed that out of 310,635 cases of hepatocellular carcinoma diagnosed from 1995 to 2015, 85% concerned people living in urban areas and 15% among those living in rural areas. The higher incidence of hepatocellular carcinoma in urban settings, according to Zhou, stems from a higher frequency of people with certain chronic liver diseases, including viral hepatitis.
Although the results of the study showed that most cases of hepatocellular carcinoma occurred in people who lived in urban areas, further analysis showed that the incidence was slowing in these communities.
However, the data indicated that there was a 5.7% annual increase in the incidence of the disease among people who lived in rural areas. This trend, according to the results, suggests that although rural areas tend to experience a significantly lower incidence rate of hepatocellular carcinoma, the disease rates approach those in urban areas.
Zhou said she and her colleagues speculated that this annual increase could come from rising obesity rates and alcohol consumption among people living in rural areas. She added that the Centers for Disease Control and Prevention reported that obesity is more common in rural areas, and further explained that obesity is associated with an increased risk of liver cancer.
“It is also possible that due to difficulties in accessing health care in rural areas, especially specialist care, fewer patients with hepatitis C are treated or treated before developing cirrhosis (chronic liver damage). ) compared to urban areas, âshe said. .
Reasons for the decline in incidence in urban areas
Data showed that some urban subgroups began to experience a decline in the incidence of hepatocellular carcinoma from 2013 and 2014. This decline occurred in men, women, youth (ages 40 to 59 years old), Asian Pacific Islanders and residents living in the western region of the United States
Zhou explained that this decline may be associated with the advances and improvements that have been made in the detection and treatment of chronic viral hepatitis B and C.
âCertain demographics, like Asians, are more likely to have hepatitis B and much more likely to live in urban areas,â she said. âSo the improvements in this group likely contributed to the declines in urban areas. “
On the other hand, no subgroup residing in rural areas experienced a decline in incidence during the study period of nearly two decades. Instead, the incidence of hepatocellular carcinoma continued to rise rapidly in males, those aged 60 to 69, non-Hispanic blacks, Native Americans / Alaska Natives, southern regions of the States. United and high poverty census areas.
During the overall study period, age-adjusted hepatocellular carcinoma incidence rates were lower in rural areas compared to urban areas.
However, throughout the study period, age-adjusted incidence rates changed significantly by race and ethnicity. Hispanic people living in rural areas had a higher age-adjusted incidence rate of hepatocellular carcinoma than their counterparts living in urban areas. The highest incidence over the 20-year period occurred among Native Americans / Alaska Natives living in urban areas, and Native Americans / Alaska Natives living in rural areas.
More research is needed
Zhou explained that it is important to continue to study health outcomes among residents of rural and urban areas. She said that due to the many differences in cancer risk factors and the frequency of medical problems among residents of rural and urban areas, cancer rates should be studied separately. Additionally, Zhou noted that there are “clear differences” in health systems that are found in urban areas. For example, residents of rural areas may have less access to valuable resources.
“The disparity in health outcomes, especially for liver cancer, between rural and urban areas is not well studied,” she concluded. “The importance of this study is to raise awareness of liver cancer as an underestimated and deadly cancer that increasingly affects people living in rural areas.”
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