Thursday, January 27, 2011

Breast implants may pose cancer risk, experts warn

The condition discussed is so rare that even if the association were proven, there would be no sense worrying about it: Just another attempt to stigmatize anything popular

US federal health officials say they are investigating a possible link between breast implants and a very rare form of cancer, raising new questions about the safety of devices which have been scrutinised for decades.

The cancer, known as anaplastic large cell lymphoma, attacks lymph nodes and the skin and has been reported in the scar tissue which grows around an implant.

The Food and Drug Administration is asking doctors to report all cases of the cancer so the agency can better understand the association. The agency has learned of just 60 cases of the disease worldwide, among the estimated five million to 10 million women with breast implants.

The agency reviewed the scientific literature going back to 1997 along with information provided by international governments and manufacturers. Most of the cases were reported after patients sought medical care for pain, lumps, swelling and other problems around the surgical site.

"We are very interested in trying to understand more specifically which patients may be at more risk and which breast implants may present a higher risk," said Dr William Maisel, FDA's chief scientist for devices.

The agency saw no difference in cancer rates between patients with saline versus silicone implants. There was also no difference between patients who got the implants for cosmetic reasons versus those who underwent reconstructive surgery after breast cancer.

Because the disease is so rare, FDA researchers suggested the issue may never be completely resolved. "A definitive study would need to collect data on hundreds of thousands of women for more than 10 years. Even then, causality may not be conclusively established," the agency said.

Still, the FDA said it is working with the American Society of Plastic Surgeons to register patients with the cancer and track them over time.

Breast implants are marketed in the US by Allergan Inc and Johnson & Johnson's Mentor Corp. Those companies will be required to update the labelling for their products to reflect the cancer reports.

A handful of researchers have published papers on instances of the lymphoma in breast implant patients over the past three years, prompting FDA's review.

Some research suggests bits of silicone can leak into skin and lymph node cells, triggering the cancer. Even saline implants include trace amounts of silicone to help them maintain shape.

The lymphoma is an aggressive form of cancer though it is often curable, according to experts. Treatments include radiation, chemotherapy and a bone marrow transplant, if the disease returns.

Reports of the cancer among women with breast implants have been reported anecdotally for years, according to Dr Jasmine Zain, a lymphoma specialist at New York University's Langone Medical Centre. "We've seen it from time to time over the years but this is the first time the FDA actually looked at all the case reports and made a statement," Zain said.

The FDA pulled silicone breast implants off the market in 1992, saying manufacturers had not provided medical data showing their safety and effectiveness. At the time, there were worries about a connection to a variety of diseases, including cancer and lupus. Alarming cases of ruptures added to the concern.

But in 2006 the agency returned the implants to the market after most studies failed to find a link between silicone breast implants and disease.

The approval came with conditions, including a requirement that the companies complete 10-year studies on women who have already received the implants to study leaks, as well conduct new decade-long studies of the safety of the devices in 40,000 women.

The FDA said the companies have continued to pursue those studies, though several of them have enrolled less than half of the patients needed to make them statistically useful.

Dr Diana Zuckerman said the studies "will be completely useless unless the FDA can convince the companies to do more to keep women in their studies". Zuckerman's group, National Research Centre for Women and Families, opposed the FDA's decision to re-approve silicone implants.

Wells Fargo analyst Larry Biegelsen, who covers the medical device industry, said the negative media coverage over the issue could hurt implant sales. "At this point, we do not expect breast implants to be removed from the market, but sales growth could be negatively impacted by the media coverage," Biegelsen wrote in a note to investors.


Scientists find key chemical that could boost memory and end the misery of Alzheimer's

Scientists have pinpointed a brain chemical that boosts memory, raising hope of new treatments for Alzheimer's. Scientists have shown that the brain chemical IGF-II plays a key role in the laying down and the strengthening of memories. Learning more about the process could lead to new memory-boosting drugs for Alzheimer’s, stroke and other conditions that rob people of their ability to remember even the simplest things.

The reverse may also be possible, with pills that wipe painful memories being used to help soldiers erase the horrors of battle, as well as those haunted by memories of car crashes and sufferers of crippling phobia.

In a series of experiments the US government-funded researchers showed IGF-II to play a key role in memory. The chemical occurs naturally in the body, and is found in relatively high levels in the hippocampus, the brain’s memory hub. However, levels decline with age.

To find out how it affects memory, rats were given mild electric shocks when they entered the darker side of a box. As the creatures normally like shaded spots, any reluctance to re-enter the area was taken to mean they remembered the painful consequences. So, the more the animal avoided the darkness, the better it was at remembering where not to go.

Tests showed that levels of IGF-II rose as the animals learnt to avoid the dark spot – and that giving them an injection of the substance boosted memory even further. New memories were strengthened and were slower to break down. In other words, the creatures found it harder to forget, the journal Nature reports.

Examination of the animals’ brains reviled that IGF-II had strengthened the cellular connections and mechanisms underlying long-term memory.

Researcher Cristina Alberini, of Mount Sinai School of Medicine in New York, said: ‘The implications of these data are far-reaching and give us new clues about how to investigate memory loss and forgetfulness in people with cognitive impairment, like those with Alzheimer’s disease, stroke or dementia.

‘This study is the first step to understanding the benefits of IGF-II. We have identified some of the mechanisms associated with this effect and look forward to studying them further and exploring the clinical relevance of IGF-II.’

With other experiments showing that blocking IGF-II stops long-lasting memories from forming, the research could also lead to pills that erase bad memories – a process known to medics as extinction.

Dr Thomas Insel, of the National Institutes of Health, which funded the research, said: ‘As we learn more about such mechanisms of fear memory formation and extinction we hope to apply this knowledge to address clinical problems, including post-traumatic stress disorder.’

The ability to erase painful memories has been the stuff of science fiction and Hollywood blockbusters for decades. In the film Eternal Sunshine of the Spotless Mind, a couple, played by Kate Winslet and Jim Carrey, undergo a procedure known as 'targeted memory erasure' to wipe out all recollection of each other after their relationship turns sour.

Dutch researchers recently discovered that beta-blocker drugs used to treat heart disease may also help patients to banish bad memories.

And scientists have shown that maintaining a stiff upper lip in times of crisis can stop bad memories from being laid down. Those who refuse to panic during moments of trauma remember less about what they saw than people who are more emotional.

It is thought that by concentrating so hard on keeping their emotions in check, they overload their brain, stopping it from taking in what is happening.

But the field is not without its critics, with some claiming that holding on to and reviewing bad memories is essential if we are to learn from our mistakes.


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