The European Journal of Cancer has published the results of a retrospective observational study that aimed to examine the association between declining use of hormone replacement therapy (HRT) and breast cancer rates in post-menopausal women in the UK.
The study collected data from the General Practice Research Database and analysed HRT usage levels and the incidence of breast cancer. The researchers found that HRT usage halved (from 40% to 20%) between 2000 and 2006 in women aged 50-54 years old. There was also a decrease in usage for women 55-59 (from 35% to 15%).
The researchers also found that the incidence of breast cancer has been dropping by 0.8% per year since 1999 in the 50-59 age group. They conclude that, "it seems probable that these two events are causally related".
Cancer Research UK has issued a press release discussing these results. They take a slightly more reserved stance on these results but note that "the parallel is striking". They also reaffirm the advice that, "women should only take HRT for medical reasons and for as short a time as possible".
Action: HRT is still useful for alleviating vasomotor symptoms and vaginal atrophy associated with the menopause. Clinicians should ensure that patients are aware of the risks of treatment and that HRT is stopped at the earliest opportunity.
The Midlands Therapeutics Review and Advisory Committee has issued advice for doctors in the West Midlands that melatonin 2mg controlled release (Circadin®) cannot be recommended due to inadequate evidence of efficacy or safety.
The review identified two randomised controlled trials that compared melatonin to placebo. No trials were identified that used active comparators.
These two trials collected primary data on subjective improvements in sleep scored using the Leeds Sleep Evaluation Questionnaire. Duration of sleep and latency of sleep were analysed as secondary outcomes.
Overall, the results did show some subjective benefit but the effect size was small. Clinically significant improvements in sleep scores were apparent from 14% of placebo users compared to 25% of melatonin users. It was also found that participants in the active treatment arm did not sleep for longer but did get to sleep 9 minutes earlier than patients taking placebo; this difference was statistically significant but the clinical significance remains in doubt.
Action: Clinicians will find that this review is a useful summary of the available data. This drug should not be in routine use due to the lack of comparative data versus existing treatments.
PLoS Medicine has published an article that debates the place of ghostwriting in medical literature.
Three viewpoints are presented in the article. One contributor suggests that ghostwriting is scientific misconduct. A second contributor suggests that the extent of ghostwriting needs to be quantified and the impact assessed. Finally, it is suggested that ghostwriters can make a legitimate contribution but concealing the contribution is dishonest and unacceptable.
Action: Clinicians should be aware of the practice of ghostwriting. Clinicians should build a portfolio of trusted sources of information and assess the reliability of information different sources.
The British Journal of Cancer has published the results of an observational prospective cohort study that aimed to assess between use of non-steroidal anti-inflammatory drugs (NSAIDs) and three types of stomach cancer. This story was reported in the wider media (BBC).
Data were collected for 311,115 individuals on self-reported use of aspirin and other NSAIDs and incidence of gastric non-cardia, gastric cardia and oesophageal adenocarcinomas. Aspirin (HR 0.64, 95% CI 0.47–0.86) or other NSAIDs (0.68, 0.51–0.92) was associated with a significantly lower risk of gastric non-cardia adenocarcinoma. There was no association with the other cancers studied.
The authors note that aspirin significantly increases the risk of gastrointestinal bleeding and haemorrhagic stroke and that these potential cancer benefits do not outweigh these risks. The recommend that further research should be conducted in a randomised controlled trial setting to confirm and quantify these findings.
Action: Clinicians should be aware of this study in light of the significant media coverage. NSAIDs cannot currently be recommended to prevent cancer because the benefits do not appear to outweigh the risks.
Thanks to Kevin Ashworth for spotting this article
An article due to be published in the journal Cancer has found an association between frequent or regular use of marijuana and testicular cancer. This story has been reported in the wider media (BBC).
The study was a population-based case-control study that compared data from 369 males diagnosed with cancer to 979 age-matched controls. All participants were questioned on their lifetime use of marijuana. The data were corrected for known cancer risk factors but it is unclear from the abstract if this including a correction for smoking regular cigarettes/tobacco.
Testicular cancer was significantly more likely in current users of marijuana (Odds ratio 1.7, 95% CI 1.1-2.5). Longer use and more frequent use of marijuana also increased the risk.
Action: Clinicians may find this data useful in discouraging younger men from using marijuana recreationally.