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It can be awkward when a patient asks you about a report in their favourite tabloid detailing an amazing research breakthrough or a ‘cutting-edge’ new treatment / test and you don’t know what they are talking about! So this section fills you in on the facts.


Vasectomy can increase risk of developing lethal prostate cancer

Published in The Telegraph, 10 July 2014.

This article was in response to the publication of a study in the Journal of Clinical Oncology from a team at Harvard Medical School. The article reports it was a study of 50,000 men, which is slightly misleading. From a 24-year prospective database of nearly 50,000 men, they identified 6023 men who were diagnosed with prostate cancer, a very large cohort nonetheless. It was identified that a relatively high proportion of these men (25%) had previously undergone vasectomy. This equated to a slight increase in relative risk of being diagnosed with prostate cancer of 1.10. The relative risk of a high-grade (Gleason 8-10) diagnosis was 1.22.

Additional analysis showed no association with testosterone levels, sexually transmitted infections or other malignancy. The obvious criticism of such a study would be that patients who have previously engaged with a urologist are more likely to seek further help, resulting in a diagnostic bias – that is to say if you go and see a doctor, you are more likely to be diagnosed with something. The researchers aimed to negate this bias by correcting for patients who had undergone a prostate specific antigen (PSA) check in the years before the prostate cancer diagnosis or were under PSA follow-up at the time of diagnosis. However, what was not widely reported in the national press is that this 50,000 strong cohort is the HPFS or ‘Healthcare Professional Follow-up Study’ based at Harvard. All of the patients are also healthcare professionals.

Many of the participants would have known worrying signs or symptoms to look out for and will likely have had no qualms about seeking medical care. This is a significant confounding factor, which cannot truly be corrected for. In conclusion, this study is likely worthy of mention in a consultation for vasectomy, but this evidence is far from definitive in light of the potential diagnostic bias and previous research having failed to show a link between vasectomy and prostate cancer.


Does riding a bicycle cause erectile dysfunction?

Broadcast on Inside Health, BBC Radio 4, 8 June 2014.

With the Tour De France recently returning to England, several bicycle-related health stories have been in the media. On Inside Health on Radio 4, Dr Margaret McCartney reported on the potential link between certain bicycle saddles and erectile dysfunction, with a useful take-home message. Dr McCartney referenced a 2008 American paper which examined erectile dysfunction in bicycle-mounted police officers.

This unique study showed that a change from a traditional saddle with a protruding front ‘nose’ to a ‘no-nose’ saddle resulted in a significant improvement in International Index of Erectile Function (IIEF) scores, apparently due to a decrease in perineal pressure. This is not a commonly taught risk factor for erectile dysfunction but may be an important question to ask in younger patients presenting with erectile dysfunction with no obvious cause. No-nose or noseless saddles are most easily ordered from online retailers.


Could global warming cause surge in kidney stones?

Published in the Daily Mail, 11 July 2014.

Researchers at The Children’s Hospital of Philadelphia report on an examination of the health records of 60,000 adults and children across five major US cities. The study correlates presentations of ureteric colic with weather patterns and temperatures between 2005 and 2011. This topic has been investigated previously in a similar manner, but there has always been the confounding factor of migration of patients from lower socioeconomic areas and countries causing a rise in stone rates at the same time as global temperatures have risen.

This paper presents a more detailed examination of the topic. The number of hot days over the course of a year bore direct correlation with the number of cases of ureteric colic presenting. Futhermore, hot spells appear to result in a rapid increase in presentations of renal colic in the following 20 days. The implications of this are two-fold; firstly, stone incidence may increase with steadily rising global temperatures. Secondly, it may be possible to use long-range weather forecasts to select the best time to take annual leave and miss the busiest on-calls!

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