Saturday, 9 June 2018

Woman survives metastatic breast cancer thanks to new treatment

A woman with advanced breast cancer has made a dramatic recovery after receiving a personalised therapy using her own immune cells. It’s the first time this type of therapy has worked in breast cancer, suggesting that it may be able to help many more people with common types of cancer, even after they’ve spread to other parts of the body.

Judy Perkins, from Florida, had breast cancer that had spread to other organs, despite trying seven other cancer treatments. “She had tennis ball-sized lesions throughout her liver, says Steven Rosenberg at the National Institutes of Health, Maryland. “It probably would have killed her in the next two to three months.”

But Rosenberg and colleagues tried a new method for boosting the immune system to treat her cancer, and six weeks later, Perkin’s tumours had halved in size. A year later, they had disappeared. Two and a half years on from treatment, she remains healthy.

More than two years later, Judy Perkins has resumed her normal life
Scott McIntyre / For The Washington Post via Getty Images
Perkins said she was “planning on dying” before she enrolled in the trial. Since having the treatment, she has resumed a normal life, including long hikes and kayaking expeditions.

The treatment works by targeting genetic mutations that are acquired by cancer cells as they grow and multiply. These mutations are different in each patient, and some cause changes in the proteins that sit on the surface of cells. These surface proteins can be recognised by the immune system, prompting it to attack the cancer cells, but this immune reaction is usually not powerful enough to fight the cancer on its own.

Powering-up this immune response is a major goal for new cancer treatments. One approach is to take lymphocytes – a type of immune cell – from a patient, grow them in the lab to obtain huge numbers of them, and put them back into the patient. So far, immunotherapies that use this or other approaches have had some success against cancers with a lot of mutations – such as skin cancer, and lung cancers linked to smoking. But until now, such treatments haven’t worked in cancers with fewer mutations, such as breast cancer.

Finding targets
The problem may be that breast cancer produces fewer mutations that provoke an immune response – usually, only around 2 percent of breast cancer mutations can do this. To get around this, Steven Rosenberg at the National Institutes of Health, Maryland, and his colleagues have been working to identify which specific immune cells in the body are capable of recognising a cancer’s mutations.

First, they sequence the DNA of a person’s cancer cells, and compare it to the DNA of their normal cells, to learn what mutations it has. They then take some lymphocytes from the patient and test them against all of the proteins that would be affected by these mutations, to see which DNA mutations are capable of triggering an immune response.

Before and after scans show the disappearance of Perkins’s secondary tumoursCourtesy of Steven Rosenberg, NIH
By doing this, the team identified types of lymphocytes that could recognise four of the mutations in Perkins’s cancer. Targeting multiple mutations is a good idea, because it means the cancer is can’t evolve to escape the immune system simply by losing one of the mutations.

The team multiplied these cells in the lab, then infused 80 billion of them back into her blood. They also gave her a type of drug – called a checkpoint inhibitor – designed to boost immune cell activity.

A range of cancers
The same approach has already been used to treat some cases of liver, colon and cervical cancer. Together, these results raise the prospect of a new approach for treating advanced cancers that have few or no treatment options left.

“These are patients with the common solid cancers for which there are no effective treatments once the cancer metastasises, so it represents a new approach to using immunotherapy for the treatment of cancer,” says Rosenberg.

“I think it’s an extremely exciting and promising strategy,” says Charles Swanton of the Francis Crick Institute, London. It shows that immune cell therapies may work not just for certain types of cancer such as melanoma, but more broadly, he says. “It’s a wakeup call to the community.”

But until a clinical trial has been conducted, we won’t know how effective the approach is. So far, the team have treated two other women with breast cancer, one of whom did not respond, and the other died before they could evaluate the treatment. Rosenberg’s team is working on improving their methods for multiple steps of their treatment.

Cell-based therapies are expensive, costing up to $500,000 per patient. But that might be justified if such treatments are curing people in their mid-40s, says Swanton.

Meanwhile, another study has found that 70 per cent of women with the most common form of early stage breast cancer do not need chemotherapy. A genetic test can identify which women can safely be treated with only surgery and hormone therapy, sparing them severe side effects such as nausea, fatigue and permanent nerve pain. The results were presented at the annual meeting of the American Society of Clinical Oncology in Chicago on Sunday.

(Source: NS)

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