This important article deals with the consequences of vasectomy.
Vasectomy is widely used to avoid pregnancies and is performed with a small outpatient procedure to bind sperm ducts.
The article is surprising for two reasons:

First of all, it seems to show that those who undergo vasectomy have 15% more diagnosed with prostate cancer, with an increased risk after 10 years.
The second observation is that vasectomics are generally healthier than the rest of the population.
So we can ask:
The subjects who undergo vasectomy are those who have a more active sex life because they are healthier?
Are vasectomy subjects healthier because they have more sex?
Do non-vasectomized subjects who are healthier have more sex?
Do non-vasectomized subjects who have more sex have a higher risk of prostate cancer?
Are vasectomized and non-vasectomized subjects healthier because they have more sex or vice versa?