Major advances in the treatment and detection of breast cancer in the last two decades have saved the lives of millions of women. Since 1990, mortality rates have decreased dramatically—by 3.3 percent a year in women under 50 and by 2 percent a year in older women. Experts say that breakthroughs made in the past few years, however, may have an even greater impact in the fight against breast cancer. Here are five reasons researchers are excited—and hopeful.
Clearer screenings
Magnetic resonance imaging (MRI), best known for its use in brain scans, is now revolutionizing breast-cancer screening and diagnosis in high-risk women. Unlike mammography, which identifies lumps and calcifications, MRI uses contrast to look at blood vessels, which can't be obscured by breast implants or naturally dense tissue. Since the blood supply to malignant cells differs from healthy cells, the cancers appear as bright spots on the digital image.
"The downside of MRI is that it picks up so much, including benign structures, that there are more recommendations for biopsies," says Dr. Christy Russell, co-director of the Breast Cancer Center at the University of Southern California. For an average-risk woman, the procedure is not worth it, she adds. For women with a BRCA1 or 2 gene mutation, however, an MRI could be lifesaving. In fact, the American Cancer Society recently updated its guidelines to recommend that all high-risk women age 40 and older be screened annually with both mammography and MRI.
Tougher drugs
Experts are optimistic about a new class of drugs known as aromatase inhibitors (AIs), "one of the most exciting things to happen in years," says Dr. Larry Norton, deputy physician in chief of Breast Cancer Programs at Memorial Sloan-Kettering Cancer Center in New York City. Many breast cancers are fed by estrogen, which tells the malignant cells to grow. In postmenopausal women, an enzyme in the breast itself, called aromatase, converts other hormones into estrogen. AIs have been used successfully to block that conversion.
In a recent National Cancer Institute of Canada study, women who were switched to an AI after two years of taking tamoxifen—a medication that's been used successfully to treat breast cancer since 1977—had 32 percent less risk of a recurrence, a new breast cancer, or death than those who stayed on the original drug.
Better biopsies
First performed on breast-cancer patients in the mid-1990s, sentinel lymph node biopsy—a procedure that involves removing one to three lymph nodes to check for cancer cells—has now become the standard of care. The technique saves patients a great deal of risk, pain, healing time, and scarring. "It used to be that we would go in and remove many of the lymph nodes from a patient's armpit to figure out if any were involved," explains Dr. Russell. "Now, if surgeons remove just one node or two nodes that are cancer-free, it is unlikely that others are involved. If it's positive, then the surgeon goes back in and removes the rest." The more nodes that test positive for cancer cells, the greater the risk of cancer recurrence.
Targeting stem cells
When you hear the term "stem cells," you likely think of the controversial embryonic type, but adults have stem cells, too. Unfortunately, so do cancerous tumors. Experts believe that, just like in healthy organs and tissue, stem cells are what spur and direct a cancer's growth. "A lot of our traditional therapies [for example, chemo] kill the surrounding cells very well, but not the stem cells," explains Dr. Max Wicha, director of the University of Michigan Comprehensive Cancer Center in Ann Arbor. "We have to figure out ways of knocking them out."
In clinical trials at the Baylor College of Medicine, at least one medication has been shown to successfully kill stem cells. Dr. Wicha's team, along with researchers at Baylor and Harvard, currently is investigating another drug, originally developed for Alzheimer's disease.
Gene-based treatments
Genetics in breast-cancer research is no longer limited to looking at the patient's genes. Now doctors and researchers are examining the genetic information of cancer cells themselves to help determine the best treatment options. One such test already is widely used with women whose cancer has not spread to lymph nodes. This type of genomic profiling also has led to the creation of super-effective drugs used to target a specific aggressive type of tumor that makes up about 15 percent to 30 percent of all breast-cancer cases.
But, experts say, what's even more important than these drugs themselves is the evidence that targeted therapies can work. Zeroing in on specific genes and molecules, Dr. Wicha says, is critical to the future of breast cancer treatment. "It's pointing us in the right direction."
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