Test 'predicts breast cancer resistance'

A genetic test could one day spot breast cancer patients most at risk of relapsing after treatment with a commonly used powerful chemotherapy.

The find could spare patients the side-effects of a drug destined to fail.

US researchers tested tumours for activity from two genes which appeared to cut the effectiveness of a class of cancer drugs.

UK cancer experts said it was another step towards "personalised" cancer treatment.

The fact that a drug may be highly effective in some patients, but not others, cannot be easily explained.

Scientists now believe that the molecular properties of patients and their tumours may be the key to understanding this - and choosing the right type of treatment.

The team from the Dana-Farber Cancer Institute, in Boston, Massachusetts, scanned the genetic code of tumours taken from women who had undergone treatment, looking for differences which could account for differences in outcome, focusing on a single class of drugs called anthracyclines.

They found a small region on a single chromosome, and within it two genes which seemed to be unusually active in drug-resistant tumours.

When checks were made on samples from 85 other women, those with high levels of activity from these two genes were those who did worst when treated with anthracyclines.

They believe that by checking tumours in advance, treatment regimes could be changed to those involving alternative drug types.

'Appropriate treatment'

Dr Eric Winer, director of the Breast Oncology Center at Dana-Farber, said: "While this work remains preliminary, it may ultimately help us use the anthracyclines in a much more thoughtful manner and allow us greater ability to personalise our breast cancer treatments to the tumour and the patient."

UK cancer charities welcomed the research, although they cautioned that it could be some time before the results were confirmed and any test developed.

Meg McArthur, from Breakthrough Breast Cancer, said: "This research is a step towards discovering why some patients benefit more than others from a common form of chemotherapy.

"Research like this is important for identifying the appropriate treatment for individual patients."

Oliver Childs, from Cancer Research UK, said: "Finding ways to predict how patients will respond to chemotherapy is important to help them benefit as much as possible from their cancer treatment.

"It is too early to say whether this research will lead to a predictive test, but work like this inches us a little closer towards an age of personalised cancer treatment."

Vaccine 'could cut HIV TB deaths'

A vaccine could cut tuberculosis cases among HIV-positive Africans by almost two-fifths, a US study suggests.

The lung infection is the most common cause of death among HIV patients in the continent.

Journal Aids reports that Dartmouth Medical School research involving 2,000 people found significantly fewer TB cases in vaccinated patients.

An expert said the jab could be a cheaper option for countries struggling to find money for extra anti-HIV drugs.

HIV patients are particularly vulnerable to TB because their immune systems are compromised.

The vaccine works by boosting the immune responses of patients who have already been given the BCG vaccine earlier in life.

In itself, the BCG jab may offer some protection against TB, but this is far from certain, and protection may only last a few years after immunisation.

The researchers from Dartmouth Medical School in the US tested it among 2,000 HIV positive patients in Tanzania over a seven-year period.

The number of confirmed TB cases was 39% lower in the vaccinated group.

First vaccine

Professor Ford von Reyn, who led the study, said it was a "significant milestone".

One theory now suggests that patients could be given the booster jab as soon as they are diagnosed with HIV, before antiretroviral drugs are needed.

Alvaro Bermejo, executive director at the International HIV/Aids Alliance, said that the other way of fighting TB in HIV patients might be to give them antiretrovirals earlier, an expensive option compared with a vaccination programme.

He said: "This is a very important finding - it is the first time we are going to have a vaccine which is influential in preventing opportunistic infections in HIV patients.

"TB is a massive problem - a third of people living with HIV in Africa are infected with it.

"The reduction of 39% seen in Tanzania, although not fabulous, is a good result."

Diabetes sugar 'can go too low'

Intense treatment to lower blood sugar in patients with diabetes could prove nearly as harmful as allowing glucose levels to remain high, a study says.

Cardiff researchers looked at nearly 50,000 patients with type 2 diabetes and found the lowest glucose levels linked to a heightened risk of death.

Significant differences in death rates between patients on insulin and those taking tablets are also flagged up.

But there could be various explanations for this, experts noted.

Patients taking insulin-based treatments have been urged not to stop taking their medication as a result of the Cardiff University study, which is published in The Lancet.

Changing treatments

Using data from GPs, the team identified 27,965 patients with type 2 diabetes whose treatment had been intensified to include two oral blood glucose lowering agents - metformin and sulphonylurea.

A further 20,005 patients who had been moved on to treatment which included insulin were added to the study.

Patients whose HbA1c levels - the proportion of red blood cells with glucose attached to them - were around 7.5%, ran the lowest risk of dying from any cause.

For both groups this risk went up by more than half if levels dropped to 6.4%, the lowest levels recorded. For those with the highest levels the risk of death increased by nearly 80%.

But the risks appeared to be particularly pronounced among those on the insulin-based regimen than those on the combined treatment.

Irrespective of whether their HbA1c levels were low or high, there were 2,834 deaths in the insulin-taking group between 1986 and 2008, nearly 50% more than in the combined group.

'Don't stop'

The authors acknowledged there could be various factors associated with this, such as these being older patients with more health problems, who perhaps had had diabetes for a longer period of time. They also make reference to a possible link between use of insulin and cancer progression that had been reported in a different study.

"Whether intensification of glucose control with insulin therapy alone further heightens risk of death in patients with diabetes needs further investigation and assessment of the overall risk balance," wrote lead author Dr Craig Currie.

"Low and high mean HbA1c values were associated with increased all-cause mortality and cardiac events. If confirmed, diabetes guidelines might need revision to include a minimum HbA1c value."

Dr Iain Frame, head of research at Diabetes UK, described the study as "potentially important" but stressed it had limitations.

"It is not clear what the causes of death were from the results reported. Furthermore, when it comes to the suggestion made in this research that insulin could increase the risk of death, we must consider important factors such as age, the duration of their diabetes and how the participants managed their condition.

"It is crucial to remember that blood glucose targets should always be agreed by the person with diabetes and their healthcare team according to individual needs and not according to a blanket set of rules."

While people would be able to manage their condition for a period with diet, exercise and even tablets, many would eventually have to move on to insulin, he noted.

"We would advise people with type 2 diabetes who use insulin not to stop taking their medication. However, if they are worried about blood glucose targets, they should discuss this with their healthcare team."

MRSA superbug strain 'tracked' via genome

Researchers have developed a technique for precisely tracking the spread of the super bug MRSA in hospitals.                                                           

The team from the Wellcome Trust Sanger Institute in Cambridge looked at the genomes of MRSA strains from across the globe and at one hospital in Thailand.

They were able to spot small changes that allowed them to track the strain back to an individual patient.

They say this adds to the understanding of how MRSA can spread so rapidly and should lead to better treatments.

DNA sequencing

The research, which is published in the journal Science, involved teams in the UK, in Bath, Oxford and London, and Thailand, Portugal and the United States.

Scientists used new high-throughput DNA sequencing technologies to compare MRSA samples from patients to show how they were genetically related.

They were able to spot single-letter differences in the genetic code.

They looked at two different sets of samples: one set taken from people across the globe and another from a single hospital in Thailand.

They sequenced the entire genomes of each sample.

In the hospital setting it revealed single letter genetic changes in the samples showing that no two infections were caused by entirely identical bacteria.

This allowed them to discover whether one patient had infected another or whether the infection had come in from another source.

They found that the MRSA strain studied acquired about one single-letter change in its genetic code every six weeks.

Worldwide search

They also looked at samples from hospitals in several parts of the world collected over more than 20 years.

The rate of mutation apparently supports the theory that MRSA emerged in the 1960s at the time of widespread antibiotic use.

Professor Sharon Peacock, a microbiologist at the University of Cambridge said: "The implications for public health are clear. This technology represents the potential to trace transmission pathways of MRSA more definitively so that interventions or treatments can be targeted with precision and according to need."

Researchers say it would be too expensive to use the technology widely at present but the cost should fall in the next few years.

Professor Mark Enright, an expert in molecular epidemiology at Imperial College, London, said the work gave researchers "a good idea as to how this particular type of MRSA has evolved and how it behaves in and out of hospitals".

"This work is a great demonstration of new, rapid DNA sequencing that in the near future will be how important pathogens such as MRSA will be identified," he said.

"Such unambiguous identification will form the basis for rapid diagnostics of microbial infection and will tell us how they spread in hospitals identifying each human host and surface in chains of transmission between patients."

Cord blood stem cell transplant hopes lifted

A technique which may eventually remove the need for matched bone marrow transplants has been used in humans for the first time.

It is hoped that "master cells" taken from umbilical cords could be used on any patient without rejection.

The latest advance, published in the journal Nature Medicine, greatly multiplies the tiny number of cells from the cord ready for a transplant.

UK charity Leukaemia Research said this could be the "holy grail" for doctors.

Aggressive treatment

The current system of bone marrow transplantation helps patients who have diseases, such as leukaemia, which affect the stem cells in their bone marrow where new blood cells are grown.

Their own bone marrow cells are killed off by aggressive treatment and cells from a matched donor are introduced in their place.

However, a matching donor cannot always be found, despite extensive donor registries held by organisations such as the Anthony Nolan Bone Marrow Trust and, even with a carefully matched donor, there is still a risk that the patient's body will reject the new cells.

Cells extracted from umbilical cords could overcome these problems - they do not have the characteristics which would normally trigger immune rejection, so it is likely that cells from a single baby's cord could be used in any patient, without the need for matching.

However, there is one big disadvantage - there are not enough cells in a single cord to meet the needs of an adult patient.

Scientists have been looking for ways to either combine the cells from more than one baby, or to "expand" the cell numbers in the laboratory.

The second of these options is far from straightforward - simply allowing the stem cells to divide and increase in the laboratory means that many of the resulting extra cells will be simple blood cells, which do not have the ability to produce new cells themselves.

Quick to work

Researchers at the Fred Hutchinson Cancer Research Center in Seattle believe they may have found a way.

They manipulated a "signalling pathway" in the stem cells to trigger an increase in numbers without losing their stem cell status.

After success in laboratory animals, these cells were used in human patients, and the researchers found that they were accepted by the body more quickly and contributed more to the rebuilding of functioning bone marrow than "non-expanded" cord blood transplants.

Dr David Grant, Scientific Director of charity Leukaemia Research said: "The holy grail is to have an 'off the peg' source of unlimited numbers of 'neutral' stem cells which can be given to any patient safe in the knowledge that they will not cause the very difficult 'graft versus host' problems that lead to rejection and often the death of the patient.

"This is a promising development towards this because the concern has been that once stem cells start 'growing' they lose their stem cell properties and progress to ordinary blood cells with a very limited lifespan."

Henny Braund, chief executive of The Anthony Nolan Trust, said the potential for umbilical cord blood was "huge", and that the charity had already imported well over 250 units of umbilical cord blood.

"Sadly in the UK, despite our scientific expertise, umbilical cord blood is still very much an untapped resource and we are only able to collect and store a tiny amount of the cords we need.

"We really need a properly resourced UK cord blood collection programme.

"Further investment is crucial if we are to capitalise on this amazing resource and save more lives."

No such thing as 'safe' cocaine, experts warn

The image of cocaine as a "safe party drug" is a myth that must be dispelled, say UK experts, as a study shows the drug is linked to 3% of sudden deaths.

The British Heart Foundation said the findings, published in the European Heart Journal, were a reminder that the drug can have devastating effects.

Although the data comes from south-west Spain, researchers said the results should apply to Europe in general.

They said anyone could suffer the deadly consequences of taking cocaine.

Fotini Rozakeas of the British Heart Foundation said: "The reality is that there are risks every time you use it.

"Cocaine can have devastating effects on the user including heart attacks, life-threatening heart rhythms, strokes and even sudden death.

"The potential deadly consequences from cocaine use can happen to anyone who takes it, even in previously young healthy people with no history of heart disease."

Deadly cocktail

In the study, 21 out of 668 sudden deaths were related to cocaine use and all of these occurred in men aged between 21 and 45.

Most involved problems with the heart and the majority of the men were also smokers and had been drinking alcohol at the same time as taking cocaine.

Lead researcher Dr Joaquin Lucena, of the Institute of Legal Medicine in Seville, said these habits added up to a lethal cocktail for the heart.

He said: "Our findings show that cocaine use causes adverse changes to the heart and arteries that then lead to sudden death."

His teams looked at post-mortem reports and investigated all the circumstances surrounding sudden deaths in Seville between 2003 and 2006.

Their findings suggested any amount of the drug could be toxic.

"Some patients have poor outcomes with relatively low blood concentrations, whereas others tolerate large quantities without consequences," they told the European Heart Journal.