Category Archives: 07 Oct 2014

Vasectomy raises prostate cancer risk by 10 per cent

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

Contraceptive pills increase breast cancer risk threefold

Bad news, girls. WDDTY wants you pregnant, barefoot and in the kitchen (albeit preparing raw food and none of those evil tomatoes). McTaggart is probably religious and has appeared on media promoting “sacred stewardship“, so this is not much of a surprise.

October 2014’s issue contains two pieces fulminating against two of the most effective forms of contraception. vasectomy and the Pill.

This article is based on a paper in Cancer Research, thus qualifying as something doctors do tell you.

Birth control pills high in oestrogen increase the risk of breast cancer by nearly three times. The risk seems to be highest in women who have only recently started taking the Pill and during the first 12 months of taking it, say researchers at the Fred Hutchinson Cancer Research Center in Seattle.

This is another case of abuse of risk ratios. The risk of breast cancer among all women in the cohort is not easy to compute form the abstract data, as the study looks only at those women diagnosed with cancer. Cohort risk then is not known, but the average lifetime risk of breast cancer in the US is currently stated to be 12.4% – this is high enough that a small percentage change in risk may be significant in absolute, not just relative terms.

The study finds that the relative risk varies from zero for some formulations, to 2.7 for the high dose oestrogen pill.

If only there were a thoroughly researched analysis available online to help unpick this complex issue. What’s that, you say? There is? I wonder why WDDTY did not bother reading this.

A large analysis of most of the studies carried out worldwide into oral contraceptives (the pill) and the risk of breast cancer, showed that women using the pill have a slight but significant increase in breast cancer risk. But the evidence suggests that the risk starts to drop once you stop taking the pill and 10 years after you stop your risk of breast cancer is back to normal.

There’s also a small increase in cervical cancer risk but this is vulnerable to confounding by levels of sexual activity. However:

The combined contraceptive pill protects you against ovarian cancer. This is particularly important if you have ovarian cancer in your family. The protection comes from the pill suppressing hormones that naturally stimulate the ovaries. It seems that the longer you take the pill, the lower your risk of ovarian cancer.

And the same goes for cancer of the uterus and the bowel.

So the reality-based take on it is:

The pill does increase the risk of some cancers, but lowers the risk of others. Any increase in cancer risk from taking the pill seems to go back to normal once you stop taking it.

Odd that WDDTY did not say this, since it’s undoubtedly what their readers need to know.

The risk is highest for high-dose oestrogen pills, which increase the risk of breast cancer by 2.7 times, while moderate-dose oestrogen ones raise the risk 1.6 times. Pills containing ethynodiol diacetate are also dangerous, raising the risk 2.6 times.

Not three times, as WDDTY says (amazing, talking up the risks, that has literally never happened in every single WDDTY story about non-quack treatments ) but not far short for one type of Pill.

High dose oestrogen is not the most common form of the Pill – in fact the most common is one of the low risk types discussed in the article (Boots has a really good comparison of Pill formulations).

All Pills are not equal. And WDDTY makes this clear in the article headline doesn’t it? Oh, wait, no, it implies the exact opposite.

In an analysis of 1,102 women who had developed breast cancer, the researchers found that most had only recently started taking the Pill, and had been using it for less than a year. Recent use increased the cancer risk by 50 per cent, irrespective of the type of contraceptive pill used.

Do you see the bit where they mention the fact that risk declines once you stop taking it? No, neither do I.

So as usual, WDDTY has engaged in scaremongering and missed an opportunity to leave its readers actually better informed about a relatively complex issue.

One can only speculate on which alternative the editors think women should use. Homeopathy, perhaps?

Chronic Lying Disease part 2

ByjnKcqCcAABtXL[1]In Treatment wars: Chronic Lying Disease we noted a regrettable tendency of quacks to promote the fictional “chronic Lyme disease”.

Note that there is nothing fictional about the symptoms, but as you’ll see in a moment they are generally either (a) hopelessly generic – “symptoms of life” if you will or (b) caused by something else.

Nor is there anything fictional about Lyme disease. It is real, a tick-borne infection caused by the borrelia burgdorferiW bacterium (in the US) or a close relative (in th Europe). The symptoms are characteristic – erythema migrans, a bull’s-eye rash – and the infection can be confirmed pathologically by blood test.

And indeed there is a real thing called post-Lyme syndrome, or post-borrelia syndrome, or “Lyme arthritis”, which is characterised by fatigue and muscular pains, especially, in patients who have had Lyme disease.

No, the fictional disease is chronic Lyme disease, which is a disease diagnosed by quacks and treated using quack treatments, especially long-term antibiotics (ironically WDDTY also fulminates against antibiotics, but promoting mutually contradictory ideas in the same story has never been a problem for the editors).

Continue reading Chronic Lying Disease part 2