Parkinson’s disease patients in Western, non-Asian populations may be at lower risk for prostate cancer, while the risk seems higher among Asian men, according to a meta-analysis study.
The research, “Association between Parkinson’s disease and risk of prostate cancer in different populations: An updated meta-analysis,” appeared in the journal Scientific Reports.
Recent epidemiological and clinical studies suggest a link between Parkinson’s and cancer. People with Parkinson’s have lower cancer rates compared to the general population, yet this association in prostate cancer remains controversial.
Researchers at China’s Second Xiangya Hospital searched for published studies analyzing the link. They initially identified 385 potentially relevant studies; their final analysis used 15 studies that included a total of 346,153 Parkinson’s patients.
Their first analysis showed that Parkinson’s patients had no more significant risk of prostate cancer than the general population. But when they examined only studies from Western populations, Parkinson’s was associated with a 17 percent lower risk of prostate cancer. This was particularly evident in men who developed prostate cancer after Parkinson’s; these men had a 23 percent risk reduction.
Asian patients, however, were more likely to develop prostate cancer. This is because of differences in genetic backgrounds and environmental exposures, researchers said. However, only one study examined the Asian population, and more studies are required to confirm the association.
The team advanced several possible mechanisms that may explain this negative association in Western populations. One is that because Parkinson’s is a neurodegenerative disorder characterized by nerve cell death, cells in Parkinson’s patients may be more likely to undergo programmed death to counteract the progression of cancer. A second explanation is smoking, which decreases the risk for Parkinson’s but modestly increases the risk for prostate cancer.
“Parkinson’s disease was significantly associated with a reduced risk of prostate cancer in the Western population,” the study concluded. “The relationship between those conditions in the Asian population needs to be confirmed by future studies.”