Some issues in medicine are complex – sufficiently complex that they actively invite Mencken’s famous expression: for every complex problem there is a solution which is simple, neat and wrong.
Other things are relatively straightforward. This October 2014 story on prostate cancer risk is straightforward, but that doesn’t stop WDDTY turning it into an alarmist anti-medicine dog’s breakfast.
Men who have had a vasectomy are more likely to develop prostate cancer and particularly the more aggressive form that’s likely to kill.
Or, to summarise as the authors did:
Our data support the hypothesis that vasectomy is associated with a modest increased incidence of lethal prostate cancer. The results do not appear to be due to detection bias, and confounding by infections or cancer treatment is unlikely.
Support the hypothesis. This is not proof of a causal link, but it is plausible. One paragraph in, then, and WDDTY have talked up “a modest increase” in a context of “conflicting reports”.
The procedure increases overall risk by 10 per cent, and the chances of developing an advanced or lethal form are even higher-compared with the general population-with an up to 20 per cent increased risk.
This is where WDDTY engages in one of its signature tactics. The paper discusses the relative risk. The difference between relative and absolute risk is very straightforward. Let’s say that you’re going to walk to the shops. You have, say, a one in a billion chance of being run over. However, on icy days, your chances of being run over are doubled, to one in half a billion. A large increase in a tiny risk is still a tiny risk. Or, to use the language of the authors, modest.
In this study, WDDTY tell us that you are 10% more likely to die of prostate cancer after a vasectomy. But the risk of lethal prostate cancer in this cohort is 1.6% : your chances of getting lethal prostate cancer (where the risk ratio is actually 1.19, not 1.1 as WDDTY simplistically state) is actually less than half a percentage point greater.
Not quite so scary now, is it?
The greatest risk was among men who had a vasectomy at a younger age of 38 or so, say researchers from the Harvard School of Public Health, who analyzed the health of 49,405 men over a 24-year period. In that time, 6,023 men developed prostate cancer and a quarter of those had had a vasectomy.
Again, the number developing prostate cancer sounds scary, but you have to put this in the context that current medical thinking is that any man who lives long enough, will probably have prostate cancer. Most men with prostate cancer die with it, not of it: they actually die of something unrelated.
Vasectomy is one of the most popular forms of male contraception in the US and UK, with around 15 per cent of men undergoing the procedure.
It is indeed. It is popular because it works, and because it is unobtrusive and allows women to stop taking the Pill, which has a higher failure rate and some side effects.
WDDTY, in its reliably inconsistent hatred of all things medical, also fulminates against the Pill. Indeed, the same issue includes a story claiming that the Pill increases risk of breast cancer threefold.
Perhaps the editors subscribe to the idea of abstinence as contraception? The evidence is that this does not work. Or maybe they are Catholics. The evidence shows that the rhythm method is one of the least effective.
In fact, vasectomy is one of the most effective forms of contraception available. Any judgement based on the balance of risk v. benefit is likely to be favourable to vasectomy.
J Cl in Oncol, 2014; doi: 10.1200/JCO 2013.54.8446