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."

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."

Nano technology tackles heart disease

A molecule designed to find, latch onto, then treat hardened arteries could offer a new way to tackle heart disease, say its inventors.

Nanoburrs, developed at the Massachusetts Institute of Technology (MIT), target only damaged cells in blood vessel walls.                                                                   

Once attached, they can release drugs in precisely the right place.

But the British Heart Foundation warned the technology was some years from being used in patients.

The hardening of the arteries which supply the heart, or atherosclerosis, can eventually lead to blockages which can cause heart attacks.

The study in the Proceedings of the National Academy of Sciences journal says specialists normally use tiny balloons to force open the vessels, then place a tube called a stent inside to keep it open.

Often the process triggers a rapid re-growth of tissue around the stent which can lead to the artery blocking again, and a recent advance has been a stent which releases drugs for a number of days after insertion to keep this process under control.

The MIT approach offers another way to get these drugs to exactly the right place.

Its nanoburrs are coated with proteins which can only stick to a structure in the blood vessel wall called the "basement membrane".

This is only exposed when the wall is damaged, so only damaged sections of blood vessel are targeted.

Once in place, a reaction takes place to release the drug over a prolonged period - up to 12 days so far.

Long way off

Professor Robert Langer, one of the authors of the research, said: "This is a very exciting example of nanotechnology and cell targeting in action."

He said the technology could target any condition in which the cell wall was compromised in this way, including certain types of cancer, and other inflammatory diseases.

Professor Peter Weissberg, medical director of the British Heart Foundation, said that while the technology was "promising", there were many time-consuming obstacles to overcome before it could be regularly used in patients.

He said: "This is an interesting proof of principle. People have been looking for a long time for ways to target a particular drug to a particular part of the body.

"It wouldn't be able to replace the need for a balloon and stent to open an artery, but it's possible that one day, it may be able to deliver a drug to treat atherosclerosis itself."

New strategies may cut screening errors, says US study

US scientists have found a way they believe may cut the number of mistakes made by medical staff looking for breast and cervical cancers.

Writing in the journal Current Biology, the researchers say that people in all walks of life looking for rare events often miss them.

But accuracy improves if people first get used to looking at samples of what they need to find.

Screening professionals said it was a recognised problem.

They carried out a study which showed that the number of mistakes made during a visual search varied according to the chances of finding the "target".

Time searching

Twelve volunteers were asked to identify target items in X-ray images of assorted objects in empty bags.

The accuracy of their search was monitored as the frequency of the target was altered.

The laboratory results are to be tested in clinics and airports.

The study found that the amount of time the observers spent looking for something depended on how often if appeared.

"If you don't find it often, you often don't find it," said lead author, Jeremy Wolfe of Harvard Medical School.

"If you are trying to find 20 cases of breast cancer from 40 mammograms, you'll find more of them than if you look for the same 20 cases from 2,000 mammograms.

"From an evolutionary point of view it makes sense for people to give up searching more quickly if they don't expect to find what they were looking for," he said.

"If you know berries are there, you keep looking until you find them. If they are never there, you don't spend your time hunting."

But this causes difficulties when the aim is to accurately spot rare phenomenon like cancers or bombs in travellers' luggage.

Instant feedback

The authors say that one benefit of staff doing a booster exercise before starting work is that it helps them to visualise what they are looking for and improves their search success rate in the subsequent session.

They say that this kind of exercise could also sharpen search skills by providing instant feedback.

In the real world it often takes many months for radiographers and radiologists to discover if they have made mistakes.

The research has been welcomed by the Society of Radiographers.

Chief executive Richard Evans said: "The difficulty of spotting abnormal results among large numbers of normal cases is a recognised problem.

"I look forward to seeing more details about this research, but radiographers would welcome techniques which help ensure the best possible standards."

He pointed out that the NHS already monitors the performance of everyone involved in breast screening through a regular audit.