Prostate cancer’s incidence and deadliness has declined or stabilized in much of the world in recent years, with the greatest decrease in risk evident in the U.S., a study reports.
These findings were presented at the recent 2019 American Association for Cancer Research (AACR) Annual Meeting, which took place in Atlanta. The research, “Global variation in prostate cancer incidence and mortality rates, 1980-2013,” was presented by MaryBeth Freeman, MPH, a senior associate scientist in surveillance research with the American Cancer Society, whose headquarters are in that cit.
Still, prostate cancer remains the second most commonly diagnosed cancer worldwide, and, the study reported, was the most commonly diagnosed cancer among men in 96 countries in 2012.
But the rate of diagnosis across countries is not fully known.
“Previous studies have indicated significant variation in prostate cancer rates, due to factors including detection practices, availability of treatment, and genetic factors,” Freeman, this study’s lead author, said in a press release. “By comparing rates from different countries, we can assess differences in detection practices and improvements in treatment.”
The cancer society researchers set out to provide an update on patterns of prostate cancer incidence and mortality in countries on five different continents, using the most up-to-date data available through the International Agency for Research on Cancer and the World Health Organization (WHO).
They examined the long-term prostate cancer trends, 1980 through 2012, as well as mortality rates across countries with high-quality data regarding incidence and mortality. (Disease incidence is a measure of the probability of a diagnosis.)
Findings for prostate cancer risk here showed a rise in incidence in four countries — the highest being in Bulgaria — and a decline in seven others, with the biggest decrease in the United States. Incidence remained stable in the remaining 31 countries. This data covered only the most recent five years.
Researchers also examined short-term trends (mostly the past five years, or 2008-12) among 44 countries with data available on incidence, and 77 countries with data on mortality.
The highest rates of incidence of prostate cancer here were found in Brazil, Lithuania, and Australia, while the lowest rates were found in India, Thailand, and Bahrain.
Five-year mortality rates were highest in the Caribbean countries of Barbados, Trinidad and Tobago, and Cuba, as well as South Africa and the eastern European countries of Lithuania, Estonia, and Latvia. The lowest mortality rates were in found Thailand and Turkmenistan.
These rates also showed a decline in reported mortality in 14 of 71 countries, a rise in three, and stabilized rates in 54 countries.
Worldwide, trends show prostate cancer remained the leading cause of death for men in 51 countries.
“Prostate cancer incidence and mortality rates are decreasing or stabilizing in most parts of the world,” the study concluded. Researchers mostly attribute these trends to early prostate cancer detection through the use of PSA screening tests.
Recent studies, however, have suggested that PSA testing may do more harm than good, leading to excessive diagnoses and unnecessary or overly aggressive treatment. The research team suggests that “future studies should monitor trends in mortality rates and late-stage disease to assess the impact of reduction in PSA testing in several countries.”
Added Freeman, “overall, patients should be having an informed discussion with their providers about the benefits and harms of PSA testing for detection of prostate cancer.”