Less invasive cancer surgery is safe and effective

In most cancer patients, axillary-lymph-node dissection (ALND) involves the removal of most of the lymph nodes in the underarm region to improve the chances of survuval, but sometimes it causes damages to the patients' arm and shoulder.

American scientists found that sentinel-lymph-node surgery (SLN), a less invasive technique that only removes the sentinel nodes, the ones closest to the breast, is safe and effective.


5,611 American women whose breast cancer did not appear to have spread to their lymph nodes were recruited to assess their differences in survival rates between the 2 types of surgery. Half of the patients had ALND surgery to remove all of the lymph nodes in the underarm area, while the other half had SLN surgery to remove the sentinel lymph nodes only. Patients were tracked over the next eight years.

The researchers found no significant differences in the patients' survival rates between the two groups. Patients who underwent the SLN procedure were less likely to experience arm problems or lymphoedema (chronic swelling of the arm). The authors concluded that "SLN surgery alone with no further ALND is an appropriate, safe, and effective therapy for breast cancer patients with clinically negative lymph nodes" and that SLN surgery "represents the next major step in reducing the extent of surgical procedures to treat breast cancer".

An accompanying comment said that the paper "vindicates contemporary practice of SLN biopsy and provides support for a reduction in extent of axillary surgery for most patients with breast cancer".


Source: Sentinel-lymph-node resection compared with conventional axillary-lymph-node dissection in clinically node-negative patients with breast cancer: overall survival findings from the NSABP B-32 randomised phase 3 trial. Lancet Oncology, 11(10):927 - 933. Published Online: 21 September 2010 (f/t via Athens)

Is glucosamine effective in reducing OA joint pain?

A BMJ study found that 2 popular supplements, glucosamine, chondroitin and their combination are no better than placebo at reducing joint pain.

The study, funded by the Swiss National Science Foundation, was a meta-analysis based on 10 randomised controlled trials with more than 3800 patients with hip or knee osteoarthritis treated with either glucosamine, chondroitin or both, followed up for 1 to 36 months. The outcome measures were pain intensity and joint structure. The analysis of data was by network meta-analysis, a relatively new statistical technique.

The researchers found that all these 2 supplements have been prescribed by GPs and rheumatologists and used widely by patients for treating osteoarthritis (OA), their study showed that glucosamine, chondroitin and their combination do not have a useful clinical effect in treating osteoarthritis. They wrote "we believe it unlikely that future trials will show a clinically relevant benefit of any of the evaluated preparations".

Critics say that the study results may be biased by the heterogeneity of the varying studies included and the network meta-analysis it used to do the calculation. Furthermore, the small size of the trials could also have large effect on the overall results.

Some patients, based on their own experience, are convinced that these supplemnets are beneficial and have written to the BMJ in response to the findings, some doctors pointed out that glucosamine has 2 different formulation, the favourable response of glucosamine to knee OA involves glucosamine sulphate not hydrochloride and that many of the recommendations of use of glucosamine are on knee OA not hip, but the study included both knee and hip OA in the analysis.

It was also noted that the conclusion of the study on the efficacy of glucosamine on knee OA is questionable because it does not include the data of the LEGS trial which investigates glucosamine sulphate in knee OA, the study is yet to be completed.

Source:

1). Wandel S, Jüni P, Tendal B et al. Effects of glucosamine, chondroitin, or placebo in patients with osteoarthritis of hip or knee: network meta-analysis. BMJ 2010; 341:c4675 ( f/t via Athens)

2). The Long-term Evaluation of Glucosamine Sulphate Study (LEGS) - study to be completed in October 2011

Revised UK guidelines for melanoma 2010

According to Cancer Research UK, the latest statistics show that 5,697 cases of malignant melanoma were diagnosed in women and 4,975 in men in the UK in 2007. If melanoma is diagnosed early, the survival statistics are very good.

Many guidelines have been drawn up by various groups and professional bodies to promote good standards of care. Last month, the British Journal of Dermatology published revised consensus guidelines for treatment and a brief overview of epidemiology, diagnosis, investigation and follow up.

The guidelines were drawn up by a multidisciplinary working party with representatives from various groups or organisations in the UK. Levels of evidence to support the guidelines are given, but the authors said that care should be individualized wherever appropriate. Where no level of evidence is quoted, it is regarded as a consensus statement, represented level IV.

Summary of the guidelines:

• Melanoma patients who must be referred from the local skin cancer multidisciplinary team to specialist skin cancer multidisciplinary team
• Recommendations for local skin cancer team record keeping of clinical features
• Recommendations for sscreening and surveillance of high-risk individuals
• Requirements for microscopy of melanoma
• Surgical wider excision margins for primary melanoma
• Staging investigations for melanoma
• Recommendations for the management of clinically node-negative patients
• Recommendations for locoregional recurrent melanoma
• Recommendations for metastatic disease
• Pregnancy, oral contraceptives and HRT
• Follow up of melanoma patients

Source:
"Revised U.K. guidelines for the management of cutaneous melanoma 2010". Published in the British Journal of Dermatology, August 2010 Vol. 163, PP.238-256. Free full text

Low-carb diet rich in meat may may cause higher health risks

Studies show that a low-carbohydrate diet produces weight loss and improves some cardiovascular risk factors, but there has been concern about the Atkin-type low-carb diet that is based on animal fat and animal protein.

Harvard reserachers examined 2 types of low-carb diets in relation to long-term health impact. They examined the data of 2 prospective cohort studies involving 85,168 women for 26 years and 44,548 men 20 yaers on a low-carbohydrate diet, either an animal-based or a vegetable-based low-carbohydrate diet. Diet was assessed via a questionnaire.

The researchers found that animal-based low-carb diets were associated with higher all-cause mortality in both men and women. A vegetable-based low-carbohydrate diet was associated with lower all-cause and cardiovascular disease mortality rates. They said the results suggest that the health effects of a low-carb diet may depend on the type of protein and fat. The mixed effects on lipid profiles may have been due to the varying amount of plant or animal fat consumed in low-carb diets.

An accompanying editorial cautioned the interpretation of this study saying that it "addresses a critical, unresolved public health question of diet but cannot satisfy us with a definitive answer", a large- scale randomised clinical trial with meaningful clinical endpoints is needed.

Source: Low-Carbohydrate Diets and All-Cause and Cause-Specific Mortality - Two Cohort Studies. Annals of Internal Medicine. September 7, 2010 vol. 153 no. 5 289-298 (f/t via Athens)

Should I take vitamin B supplements for mild memory problems?

Oxford scientists investigated the effects of vitamin B on brain atropy ( the loss of neurones and their connections) in people with mild memory problems. Studies have found that high levels of homocysteine (tHcy), an amino acid in the blood, affect the rate of brain atropy and that raised levels of tHcy increase the risk of Alzheimer's disease.

168 elderly people with mild cognitive impairment but not taking anti-dementia drugs were recruited in the Oxford area. Both the volunteers and researchers were unaware of the treatment received, either high dose of vitamin B tablets ( a combination of folic acid, B12 and B6) or placebo pills for a 2 year period.

The researchers found that taking B vitamins for 24 months led to brain shrinkage and the rate of shrinkage in the treatment group was 30% less than the placebo group. They concluded that a simple and safe treatment can slow down the rate of brain atropy in people with mild cognitive impairment. The study was published in PLoS One, a peer-reviewed journal. A study published in 2008 in JAMA showed conflicting results.

Critics say that this is well-conducted randomised controlled trial with promising results. However the evidence did not show brain shinkage may lead to improvement in symptoms or that the B vitamins can prevent Alzheimer's disease, but warrant more research.

Source: David Smith A, Smith SM, de Jager CA et al. Homocysteine-Lowering by B Vitamins Slows the Rate of Accelerated Brain Atrophy in Mild Cognitive Impairment: A Randomized Controlled Trial. PLoS One 5(9): e12244

The Avandia scandal

An investigation by the BMJ published this week calls for the withdrawal of the daibetes drug, Avandia, immediately from the market because of the concerns that it may increase the risk of myocardial infarction and the paucity of good evidence to support its use.

Rosiglitazone, also known as Avandia, was GSK's second biggest selling drug, introduced in 1999 and is widely used to lower blood glucose levels in patients with type 2 diabetes. It was approved by the EMA in 2000 despite concerns over its safety.

In 2007, several studies found Avandia having harmful effects and issued serious health warnings. The researchers questioned why Avandia is still available on the market and why physicians would prescribe it to diabetic patients when there are other drugs without these side effects. They called for Avandia to be withdrawn from the market. Since then, the sales of Avandia fell sharply.

The BMJ investigators found that in July, the UK Commission on Human Medicines advised the MHRA to withdraw Avandia as the risks of Rosiglitazone outweigh its benefits. This has raised a lot of questions about the quality of the data used in the studies and the lack of trial results made available to the public. The investigators also ask why the regulators accept such poor evidence on benefit and safety, why patients in the UK and Europe are not make aware of the concerns about this drug and whether the current regulatory body is doing its job properly. They said that doctors are advising that no new patients shoud use this drug, existing diabetic patients should review their options and those at high risk of heart disease should stop taking it.

In the accompanying editorial, the authors said that clinicians had focused on the wrong endpoint and lost sight of the main reason for treating this disease, "which is not to reduce glycaemia but to prevent complications". They went on to say that clinicians need to be "absolutely certain that the long term treatment for type 2 diabetes are not causing the harm they are meant to prevent" and should insist on robust evidence of benefits and harms.

Professor Freemantle noted in the accompanying commentary that the Avandia studies were hindered by inadequate data due to high levels of loss to follow-up. He wrote "In order to learn from our mistakes, we must improve the quality of safety data from clincal trials on all new healthcare interventions, not just antidiabetic drugs" and an overhall in the standards of regulatory trials is needed.


Sources : free f/t
Rosiglitazone: what went wrong? BMJ 2010; 341:c4848 (Published 6 September 2010) Editorial - Licensing drugs for diabetes BMJ 2010; 341:c4805 (Published 6 September 2010)
Commentary: What can we learn from the continuing regulatory focus on the thiazolidinediones?BMJ 2010; 341:c4812 (Published 6 September 2010)