Last week, researchers reported that infertile men are at an increased risk for developing aggressive prostate cancer, and I have been getting a lot of questions from my patients, so I decided to answer some of them here for all of you.
1. What were the findings of this study? This study looked at two patient populations from fertility clinics from 1967 through 1998. There are two distinct groups of men studied with infertility: Men with male factor infertility and those without, defined by an abnormal semen analysis.
This study shows that men who have male factor infertility have a greater risk of developing high grade prostate cancer. When adjusted for age, men who have male factor infertility are 2.6 times more likely to develop high grade prostate cancer and 1.6 times more likely to develop low grade prostate cancer compared to man who are fertile.
2. Why are they significant?While the absolute risk of men developing prostate cancer remains small, these findings suggest that men with male factor infertility have higher rates of high grade prostate cancer. This high grade cancer is more difficult to treat, has a greater impact on quality of life, and increases the risk of prostate cancer mortality.
3. What is the link between infertility and prostate cancer?The biological link between male factor infertility and prostate cancer remains unknown. An explanation proposed by the authors of the study suggests that a common underlying etiology is responsible for both prostate cancer and infertility. Furthermore, scientists have hypothesized that damages to the Y chromosome, faulty DNA repair, or environmental toxins could serve as a link between the etiology of prostate cancer and infertility.
4. Who is at risk for developing prostate cancer?Previous studies have established that men who are older, African-American, or with a family history of prostate cancer are more likely to develop prostate cancer. Studies also suggest a link between obesity and prostate cancer. This current publication suggests that men with male factor infertility are also at an increased risk for developing prostate cancer.
5. What are some ways to protect yourself from prostate cancer? Although there have not been any proven methods to prevent prostate cancer, there are certain steps men can take to lower their risk of developing prostate and identifying prostate cancer at an early stage to increase the likelihood of a curative therapy. There have been studies showing a benefit of finasteride (Proscar) and dutasteride (Avodart) in reducing the risk of prostate cancer. Further investigations are currently underway. Studies have shown that statins (Lipitor, etc) and lycopene (tomatoes) may also reduce the risk of prostate cancer. However, selenium and vitamin E have not been shown to reduce the risk of prostate cancer as previously thought.
One of the most important actions men can take is to discuss screening for prostate cancer with their physicians. Screening includes a digital rectal exam and a blood test for prostate specific antigen (PSA). According to the new guidelines proposed by the American Urologic Association in 2009, patients should undergo a PSA screening at the age of 40. However, patients should discuss prostate cancer screening with their physicians early on in order to develop a screening plan that's right for them. In light of this current publication, men with male factor infertility should be more vigilant in their screening practices.