As one type of esophageal cancer declines, another rises sharply

Last Updated: 2017-06-27

By Scott Baltic

NEW YORK (Reuters Health) - Even as the incidence of esophageal squamous cell carcinoma (ESCC) continues to decline in most countries, the incidence of esophageal adenocarcinoma (EAC) is rising to at least a comparable extent, according to a new study of 12 nations.

As a result, the researchers conclude, “The burden from EAC is expected to rise dramatically across high-income countries and has already or will surpass ESCC incidence in the coming years, especially among men.”

The paper, released online on June 6 by the American Journal of Gastroenterology, highlights several aspects of these opposing trends:

- EAC has already surpassed ESCC in many countries and is set to become the most common subtype of this cancer in western countries.

- By 2030, one in 100 men in the Netherlands and the UK is predicted to be diagnosed with EAC before age 75.

- Even in nations where EAC rates are not predicted to increase, the burden in terms of new cases will continue to rise, because of population aging and growth.

- Declines in ESCC incidence in men are consistently being offset by increasing EAC rates among the predominantly Caucasian populations under study.

The French and U.S. authors note that esophageal cancer is the eighth most common malignancy worldwide and that previous studies have described its changing epidemiology.

This shift in histologic type “is most important for prevention and diagnosis and the change in at-risk groups and factors driving the risk of disease,” co-author Dr. Linda Morris Brown, of the Biostatistics and Epidemiology Division, Environmental and Health Sciences Unit at RTI International, Rockville, Maryland, told Reuters Health by email.

For example, she explained, in the U.S., overall esophageal cancer rates are driven by striking decreases in ESCC among whites and African-Americans and dramatic increases in EAC, especially among white men.

The decreasing rates among African-Americans reflect declines in ESCC that are at least partly attributable to the decreasing prevalence of cigarette smoking and alcohol use, Dr. Morris Brown explained. At the same time, the increases among whites reflect rapidly rising rates of EAC resulting from substantial increases in Barrett’s esophagus (the precursor lesion for EAC) that are not offset by declines in ESCC.

Co-author Dr. Susan S. Devesa, of the Division of Cancer Epidemiology and Genetics at the National Cancer Institute, Bethesda, Md., agreed. She told Reuters Health in an email, “Most likely the declines in the prevalence of cigarette smoking and hard liquor consumption are driving the decreases in ESCC, and increases in abdominal obesity and Barrett’s esophagus are contributing to the increases in EAC.”

She emphasized that the study “focused on incidence data based on cases newly diagnosed with disease, not mortality data based on deaths.”

“Several studies in the past two decades have shown a startling increase in the incidence of esophageal adenocarcinoma concurrent with a decrease in the incidence of squamous cell carcinoma, particularly in western Europe, the United States, and Australia,” Dr. Amitabh Chak of University Hospitals Cleveland Medical Center, told Reuters Health by email.

ESCC “is strongly associated with smoking and alcohol intake, and the falling rates are likely a result of successful efforts to curb smoking,” he said. “The increase in adenocarcinoma is more puzzling and may be related to increases in the prevalence of obesity, the eradication of Helicobacter pylori from the widespread use of antibiotics, or some other change in the environment of developed countries.”

“Esophageal adenocarcinoma, which was a rare cancer three decades ago, will become an increasingly important public health issue,” warned Dr. Chak, who was not connected with this study.

The study drew data from 42 registries in 12 countries, from the last three volumes of Cancer Incidence in Five Continents. The years of diagnosis were 1988-2007, and the 12 countries were the U.S., Canada, Japan, Australia, Denmark, the UK, France, the Netherlands, Croatia, Italy, Spain, and Slovakia.

SOURCE: http://go.nature.com/2sYaSme

Am J Gastroenterol 2017.