Nearly 1.7 million women globally were diagnosed with breast cancer in 2012, amounting to 25% of all cancers in women. Breasts—life-giving symbols of fertility—are also potential hosts to the fifth deadliest cancer worldwide.
The survival rate for metastatic breast cancer, which happens when the cancer has spread elsewhere in the body, is only 22%.
But this week, scientists have announced two big findings that could dramatically change how breast cancer is treated. Both underscore the increasing need for individualized approaches to cancer, a complex illness that manifests itself in different ways depending on the person.
“We need a new paradigm for cancer therapy,” said Dr. Steven Rosenberg, an oncologist and immunologist at the National Cancer Institute (part of the National Institutes of Health) who has been developing a new approach that harnesses patients’ immune systems. “Highly personalized treatments are likely to be necessary if we are to make progress in treating common cancers.” He and his colleagues have published their new research in Nature Medicine.
Rosenberg’s team has tapped into the power of patients’ own immune systems, using them to home in on certain cancer-specific mutations. So far, such immunotherapies have only succeeded in combatting cancers that have lots of mutations—like skin cancer and lung cancers associated with carcinogens like tobacco and exposure to ultraviolet radiation. The more mutations a cancer has, the higher the chance that the immune system will recognize some of them. Only about 2% of breast cancer mutations elicit a reaction from the immune system. But Rosenberg’s treatment—the first to eradicate breast cancer in a patient with an advanced form of the illness—identifies the particular white blood cells, or lymphocytes (which must be able to get into the breast cancer tumor or the area surrounding the tumor to be effective) that are sensitive to certain DNA mutations. It’s a matching game of infinitesimal proportions.
Judy Perkins, 52, was “planning on dying” before she enrolled in Rosenberg’s trial. She had advanced, metastatic breast cancer originally diagnosed in 2003 but then re-diagnosed about a decade later. She had tried everything and was beginning to give up hope. Then she heard about the experimental treatment at the NIH and decided to give it a shot.
Rosenberg’s research group pinpointed the types of lymphocytes in her body that were capable of recognizing four of the mutations in her cancer. The team then multiplied these white blood cells in a lab and injected 80 billion of them back into her bloodstream. They also gave her a drug that helps support immune cell activity. Today, two and a half years after her treatment began, Perkins is healthy and cancer-free.
Rosenberg says that in treating 45 patients with a variety of cancers—including colon, liver, and cervical cancer—seven of them have benefited. What’s more, 80% of these patients appear to already have lymphocytes that react to their own cancer, and all but one of the mutations that their immune systems recognized were only found in one person’s body—that is, each cancer has its own very unique fingerprint.
In other words, if you were to develop cancer in your lifetime, there’s a good chance your body likely already contains a smattering of the specific ingredients necessary to ward it off. You’ll just need some assistance in amplifying that army of lymphocytes inside you.
“The development of this approach holds the best opportunities for finding effective immunotherapies for patients with the solid cancers that last year caused over 500,000 deaths in this country,” Rosenberg said.
Others not affiliated with the research agree. “I think this novel therapy is exciting because it can transcend various tumor types,” said Margaret Gatti-Mays, co-director of the Clinical Trials Group at NIH’s Laboratory of Tumor Immunology and Biology.
More broadly, she said, “the field of immunotherapy is exciting because we have found that by targeting and engaging the immune system, immunotherapy can produce profound and long-lasting tumor control—whereas chemotherapy targets the cancer and its effect lasts as long as the drug in the system.”
The new treatment, if made available to more people, could be a good option for women who have not done well with chemotherapy or existing immunotherapies. However, it doesn’t work for everyone, and a large-scale clinical trial is still in the works.
The reasons for a therapy’s failure are often quite nebulous. “It’s not that the patients don’t have the correct blood cells to fight off cancer,” Gatti-Mays said. “It’s generally that the immune system doesn’t see the cancer or is fatigued from trying to engage the cancer. These ‘fatigued’ or ‘blinded’ white cells are the target of many immunotherapies.”
But a tumor could try to evade the immune system a different way, even if these tired blood cells are re-awakened. Also, even within a single patient, various parts of separate tumors can respond to treatment in different ways. Gatti-Mays suggests that a combination of treatments—immunotherapy, chemotherapy, radiation—could make the biggest difference.
Meanwhile, another major study published this week in the New England Journal of Medicine has found that 70% of women with the most common form of early stage breast cancer do not need chemotherapy. A genetic test, the scientists say, can help determine whether or not a patient can safely undergo just hormone therapy or surgery…or both. This could spare up to 60,000 women of the violent chemo process, which comes with a host of unpleasant, life-altering side effects.
However, in the team’s research, there was a group of women under the age of 50 who had breast cancer who still appeared to reap some benefits from chemotherapy.
“For younger women, doctors still need to sit down and talk to the patient,” said George W. Sledge, Jr. of the Stanford University Medical Center and senior author of the study. Overall, though, Sledge says the revelation is “a win for women and a win for society.”
Mary Lou Smith, co-founder of the Research Advocacy Network, two-time breast cancer survivor, and one-time ovarian cancer survivor, says this “exceedingly important” test will be the “gold standard” for eligible patients.
“I had chemotherapy five years ago for ovarian cancer and I would have jumped at the chance to take a test that would have given me more information,” she said. “For a patient to know they will or will not benefit from taking a treatment with its accompanying side effects is a game-changer. This is the research of the future—being able to match the right patient to the right drug at the right time.”
Aparna Nathan contributed reporting.