Male Infertility May Increase Risk for Aggressive Prostate Cancer
Researchers have found a link between male infertility and an increased risk for developing an aggressive form of prostate cancer. While some feel it may be a helpful tool in identifying men who would most benefit from screening for the disease, health experts from both the American Urological Association and the American Cancer Society disagree.
Researchers from the University of Washington in Seattle tracked about 22,500 Californian men who had been evaluated for infertility in 15 clinics between the years 1967 and 1998. Overall, 1.2% of the infertile men eventually developed prostate cancer, compared to 0.4% of men who were later deemed normal. After accounting for factors such as age, infertility increased the chances of being diagnosed with slow-growing tumors 1.6 times and aggressive tumors 2.6 times.
Aggressive or high-grade tumors were based on a Gleason score of 8 to 10.
Dr. Thomas Walsh, who led the research said that it was surprising to see such a high rate of aggressive prostate cancer among these men. The association could not be explained by the finding that men who were seeking treatment for infertility were more likely to have cancer diagnosed simply because they were more proactive in receiving health care. Had that been the case, Dr. Walsh said that both types of cancers would have had the same rate of increase.
The authors speculate that environmental influences may have an effect, such as toxins that damage the male sex chromosome. Ed Yong of the Cancer Research UK agrees, saying 'It's unlikely that being infertile directly leads to prostate cancer. Instead, both infertility and a higher risk of prostate cancer might stem from a common genetic fault, or some aspect of our lifestyle or environment.' For example, recent studies have found that defects on the Y chromosome are linked to both infertility and prostate cancer.
Other risk factors for prostate cancer include older age, being African-American, family history, and obesity. Diet and exercise may be factors in preventing some forms of prostate cancer.
While infertility may lead to more aggressive forms of prostate cancer, both the American Urological Association and the American Cancer Society do not recommend changing the current screening guidelines to include young men with fertility problems. The AUA recommends that men begin prostate cancer screening at age 40 and the Cancer Society recommends that most men begin the discussion with their doctor on screening at age 50.
Prostate cancer is the most common cancer among men and the second highest killer. Approximately 35,000 men are diagnosed each year.
"Increased risk of high grade prostate cancer among infertile men." Thomas J. Walsh, Michael Schembri, Paul J. Turek, June M. Chan, Peter R. Carroll, James F. Smith, Michael L. Eisenberg, Stephen K. Van Den Eeden, and Mary S. Croughan. Cancer; Published Online: March 22, 2010 (DOI:10.1002/cncr.25075).