Wednesday, June 23, 2010

Do B vitamins reduce lung cancer risk?

Smoking is the major risk factor for lung cancer, according to a new study published in JAMA, higher levels of vitamin B6 and methionine in the blood was associated with lower risk of lung cancer.

This was a large scale IARC study with 520,000 volunteers across Europe, part of the EPIC cohort. Blood samples were taken from both the case group and the control group and the amount of B6 and methionine measured.

The researchers found that there was a lower risk of lung cancer with a higher level of B6 and methionine whether they were smokers or non-smokers. Overall, people with above average levels of B6 and methionine had 50% reduction in the risk of developing lung cancer than those with below average levels.

Critics say that the blood samples were taken on only one occasion and a cohort study cannot prove a cause and effect for a reduced risk of lung cancer for B6. Furthermore, B6 and methionine are found in meat and potatoes, but it was unknown whether eating more of this food would make a difference to the risk of developing lung cancer because a lower level of these substances in the blood may be due to poor absorption.

Source: Johansson M, Relton C, Magne Ueland P, et al. "Serum B Vitamin Levels and Risk of Lung Cancer". JAMA 2010; 303: 2377-2385

Tuesday, June 22, 2010

Racial gaps in lung cancer surgery

A new study published in JAMA found that black patients newly diagnosed with lung cancer were less inclined to have surgery than whites because they did not connect well with their doctors.

Researchers analysed data from 386 lung cancer patients in Carolina and found that only 55% of black patients had surgery compared to 66% of white patients. They found that many black patients misunderstood their prognosis or did not feel comfortable enough to discuss with their doctors treatment options and outcomes. Black patients were also less likely to have other sources of support.

The authors said that there are many barriers to improving the disparities but doctors and hospitals can work on the negative perceptions of patient-physician communications and spend more time with patients about their treatment options.


Source: "Factors Associated With Decisions to Undergo Surgery Among Patients With Newly Diagnosed Early-Stage Lung Cancer". JAMA, 2010; 303 (23): 2368-2376

Are HRT patches safer than pills?

A large study including 75,000 women suggests that low-dose HRT patches may be safer than tablets in terms of stroke risk, but the risk increases significantly with high dose patches.

The findings are based on a nested case-control study drawing data from the General Practice Research Database in the UK. Researchers compare a group of women who have stroke ( case group) to a group who do not ( control group) and found that women using low-dose HRT patches had no increased risk of stroke compared with those who had not used HRT patches, however, using high-dose patches had an increased risk of 89% compared with non-use.

Researchers concluded that low-dose HRT patches may be a safer alternative to oral HRT, although these results alone cannot prove causation, "this study should encourage further research on the importance of the route of administration to define the role of transdermal oestrogens in the therapeutic arsenal for the treatment of menopausal symptoms."

Critics say that this study could affect prescribing practice but it only looked at stroke risk while HRT is assocaited with other risks such as breast cancer, venous thromboembolism and heart disease. The study was published in the BMJ.

Source: Renoux C, Dell’Aniello S, Garbe E and Suissa S. Transdermal and oral hormone replacement therapy and the risk of stroke: a nested case-control study. BMJ 2010;340:c2519, (Published June 3 2010) full text via Athens

Brush your teeth twice a day could lower cardiovascular risk

According to a new research by University College London, published in the BMJ, people who brushed their twice a day had a lower risk of heart disease compared with those with less frequent toothbrushing.


The researchers analysed data from more than 11,000 adults who took part in the Scottish Health Survey between 1995 and 2003. Each survey was linked to hospital admissions and deaths, followed up until 2007. They found that people who rarely brushed their teeth had a 70% greater risk of cardiovascular disease than those who brushed their teeth twice a day. However they said that the study did not prove a cause and effect association between oral health and cardiovascular disease.


Previous studies have established a link between gum disease and cardiovascular risk, but the researchers said this is the first study to show an association between self-reported toothbrushing and incident cardiovascular disease and suggest "a possible role of poor oral hygiene in the risk of cardiovascular disease via systemic inflammation." They noted that further studies are needed to confirm whether the observed association is causal or merely a risk marker.


Source: Toothbrushing, inflammation, and risk of cardiovascular disease: results from Scottish Health Survey. BMJ 2010;340:c2451