From the Journals

Global stomach cancer deaths decline as colorectal cancer deaths stagnate, rise



A global analysis of premature deaths from noncommunicable diseases (NCDs) has shown mixed results for gastrointestinal (GI) cancers.

The data suggest fewer people are dying from stomach cancer, but in some countries, the risk of colorectal cancer death is increasing or declining much more slowly than other causes of premature death.

As for other cancers, in more than half of the countries analyzed, the risk of liver and prostate cancer death is on the rise in men, and the risk of lung cancer death is on the rise in women.

The global decrease in the risk of stomach cancer death may be explained by the fact that stomach cancer’s main cause is Helicobacter pylori infection, which correlates with general food hygiene, the study’s corresponding author Majid Ezzati, PhD, professor of global environmental health at Imperial College London, said in an interview.

“Factors such as more widespread electrification and refrigeration tend to drive the rates down,” he explained.

Dr. Ezzati and colleagues detailed their findings in the second edition of the NCD Countdown 2030 report, recently published in The Lancet.

The report revolves around the Sustainable Development Goal (SDG) target 3.4, which is to reduce premature deaths from NCDs by one-third between 2015 and 2030. The causes of death include cancer, cardiovascular disease, chronic respiratory disease, and diabetes, which are collectively known as NCD4. “Premature” deaths are defined as deaths in people aged 30-70 years.

SDG target 3.4 is still attainable, according to Dr. Ezzati and colleagues. However, their report showed that many countries are falling short of this goal.

The findings come from an analysis of 2016 World Health Organization global estimate data on age-, sex-, and cause-specific mortality for 176 countries and territories with at least 200,000 inhabitants. Mathematical modeling was used to assess the number of approaches countries used to accelerate declines in mortality.

Results of the analysis

“Trends in the risk of death from 2010 to 2016 varied considerably among NCD4 causes of death,” Dr. Ezzati and colleagues wrote.

Stomach cancer, ischemic and hemorrhagic stroke, ischemic heart disease, and chronic respiratory diseases had the fastest rates of decline among risks of premature death.

In fact, stomach cancer was the fastest declining cause of death in 45 countries (25.6%) among men and in 40 countries (22.7%) among women.

On the other hand, the risk of premature death from colorectal, liver, breast, prostate, and other cancers declined more slowly than the risk of premature death from other NCDs.

The risk of death from colorectal, liver, and prostate cancers in men and lung cancer in women rose in more than 50% of the countries surveyed.

“The median annual rate of change in the probability of dying prematurely from various causes ranged from +0.2% per year for lung cancer to –2.5% per year for hemorrhagic stroke in women, and from +0.5% per year for colorectal cancer to –1.8% per year for hemorrhagic stroke in men,” the investigators summarized.

Explaining the GI cancer results

“There are dramatic differences between the upper and lower GI tract, both in terms of anatomy/embryologic origin but also in terms of exposures,” observed Mark Lewis, MD, medical director of the gastrointestinal oncology program at Intermountain Healthcare in Salt Lake City, in an interview.

H. pylori infection, family history, and diet factor into stomach cancer risk, Dr. Lewis said.

While family history isn’t modifiable, “we are much better now at identifying and eradicating the potentially carcinogenic H. pylori bacterium. In terms of diet, the advent of modern refrigeration has made the prevalence of heavily salted/preserved foods decline,” he added.

A 14-day course of treatment (with a proton pump inhibitor and antibiotics) can eliminate H. pylori, Dr. Lewis continued. “The prophylactic effect against gastric cancer is massive, cutting risk by roughly half,” he said.

At least in the United States, colorectal cancer rates have declined in people 50 years and older, but rates have risen sharply in younger age groups, increasing by 2% annually in the last decade, according to statistics in CA: A Cancer Journal for Clinicians.

“One prevailing theory is prior antibiotic prescriptions [even in childhood] might perturb the microbiome of the lower GI tract and predispose to cancer,” Dr. Lewis said, pointing to a recent study in the British Journal of Cancer that identified an association between repeated antibiotic use and colorectal cancer.

Reducing NCD deaths

Dr. Ezzati and colleagues said six high-income countries – Denmark, Luxembourg, New Zealand, Norway, Singapore, and South Korea – are likely to meet SDG target 3.4 if they maintain or exceed average rates of decline seen during 2010-2016. Seventeen countries are on track to reach the target for women, and 15 countries are on track for men.

High-income countries in Asia-Pacific, western Europe, Australasia, and Canada have seen the lowest NCD4 mortality risk, whereas low- and middle-income countries in sub-Saharan Africa and men in central Asia and eastern Europe have seen the highest risk.

“To move forward, we must learn from those countries that are doing well and replicate their strategies to NCD prevention and healthcare,” Dr. Ezzati said in a statement. “Our analysis shows that every country still has options to achieve SDG target 3.4, but they need to address multiple diseases and have strong health systems.”

Increasing access to effective cancer screening and diagnosing and treating cancers earlier could help reduce long-term health consequences and premature deaths from cancer, according to Dr. Ezzati and colleagues. Screening would help even the playing field on cancer diagnosis and survival rates between higher-income countries and low- and middle-income countries.

“This approach will allow earlier diagnosis during precancerous or early stages of disease, followed by treatment of those cancers with effective treatment,” the authors stated.

Tobacco and alcohol interventions and increasing access to quality primary care would also help tamp down on NCD-related deaths.

The authors acknowledged that low-income countries, which may be struggling with other health crises such as COVID-19 and Ebola, may find it a challenge to stage such interventions.

“COVID-19 has exposed how a failure to invest in effective public health to prevent NCDs and provide health care for people living with NCDs can come back to bite us,” said Katie Dain, CEO of the NCD Alliance.

“The good news is that all countries can still meet the 2030 targets, with sound policies and smart investments. NCD prevention and treatment can no longer be seen a ‘nice to have.’ It must be considered as part of pandemic preparedness,” she added.

COVID-19 should serve as an impetus for governments to invest in healthier lifestyle and diet habits and curb alcohol and tobacco use, according to an editorial in The Lancet related to the analysis.

The current report updates 2018’s first NCD Countdown Report, which linked NCD4 conditions to approximately 32 million or 80% of NCD deaths. Unlike the recent report, 2018’s data didn’t focus on specific diseases.

The current report was funded by Research England. Dr. Ezzati received a charitable grant from the AstraZeneca Young Health Programme and personal fees from Prudential and Scor, outside of this report. None of the other authors reported competing interests. Dr. Lewis has no relevant disclosures except that he is a commentator for Medscape, which is owned by the same parent company as MDedge.

SOURCE: Bennett JE et al. Lancet. 2020 Sep 3. doi: 10.1016/S0140-6736(20)31761-X.

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