The outlook for patients diagnosed with breast cancer has been changing for the better over time, with several significant advances coming through in the past 10 years. Along with more-effective therapies with fewer side effects than traditional treatment, a greater understanding of risk and accessible preventive measures has given women everyday tools to protect themselves against the disease.
Five particular advances have made a notable impact on the lives of breast cancer patients during the past 10 years. These include HER2-directed therapies, gene expression testing, hormonal therapy, less-invasive surgery, and healthy lifestyle choices aimed at prevention.
Wendy Chen, MD, MPH, medical oncologist at the Dana-Farber Cancer Institute, says that therapies targeted at HER2—human epidermal growth factor receptor 2, a protein that promotes the growth of cancer cells—have had an important impact on breast cancer survival. Though not all breast cancers overexpress HER2, those that do (about one in five) can be effectively treated with drugs that target this protein. These include Herceptin® (trastuzumab), Tykerb® (lapatinib), and the recently approved Perjeta™ (pertuzumab).
“HER2-directed therapies have revolutionized the treatment of HER2-positive breast cancer,” says Dr. Chen. She explains that because these drugs are used for both early- and late-stage breast cancer, they can benefit a wide range of patients (so long as the cancers overexpress HER2) and can help reduce recurrence risk in early-stage disease.
2.Gene Expression Testing
Tests to determine the types of genes that a cancer expresses (also known as assays) have allowed doctors to tailor therapies to a patient’s individual needs. In breast cancer doctors are using two assays—Oncotype DX® and MammaPrint®—to help determine a patient’s risk of recurrence or spread (metastasis) based on the types of genes that the cancer expresses (a process known as gene subtyping) and to plan treatment to most effectively reduce this risk. Specifically, these tests help determine which patients are more likely to benefit from treatment with chemotherapy in addition to hormonal therapy.
“These [tests] have been very effective in helping us see who would most benefit from chemotherapy and who would most benefit from just [hormonal] therapy,” says Jennifer Litton, MD, a medical oncologist and assistant professor in the department of breast medical oncology at the University of Texas MD Anderson Cancer Center.
Hormonal therapy, which is used to prevent estrogen from binding to the estrogen receptor–positive disease (cancer that is stimulated to grow by estrogen) is not new to breast cancer; tamoxifen, for example, has been available for more than 30 years. Continuing refinement of this type of treatment, however, has given patients more options. With these improvements, says Dr. Litton, “we’re able to really effectively block estrogen synthesis and effectively treat many cancers using [hormonal] therapies without having to use chemotherapy.”
It now appears that some women with early-stage breast cancer may be candidates for less-extensive surgery to stage the disease. To determine whether and to what extent cancer may have spread to a woman’s lymph nodes, nodes are removed for evaluation. Surgical options include an axillary node dissection, in which many nodes may be removed, and a sentinel node biopsy, in which only the sentinel nodes (those most likely for cancer to have spread to first) are removed. Women with no evidence of cancer in their sentinel nodes may be able to skip further axillary node dissection as well as the side effects associated with more-extensive surgery.
Though not every breast cancer patient is a candidate for less-extensive types of surgery, these approaches have become more widely used. Dr. Chen says that there is a “general trend toward less-invasive surgeries.” She explains that surgeons, for example, “do more sentinel node biopsies instead of axillary node dissections.” She adds, however, that not all patients are eligible for sentinel node biopsies alone and that some need the more-extensive surgery to determine the extent to which the cancer has spread; only those without cancer found in a sentinel node biopsy are eligible for the less-extensive approach (sentinel node biopsy only). Dr. Litton also stresses that trial findings indicate less need for extensive surgeries in some breast cancer patients but that more-extensive approaches are still indicated for others.
5.Exercising and Maintaining a Healthy Weight
“Over the past five to 10 years, there has been increasing understanding of the role of overweight and obesity and physical activity in terms of breast cancer risk,” says Dr. Chen. The benefits of these healthy lifestyle measures, she explains, apply to survivors, as they can reduce the risk of recurrence, and also to people who have not been diagnosed, as maintaining a healthy weight and exercising appear to help prevent a primary diagnosis.
“There’s no magic diet,” Dr. Litton explains, “but across the board weight loss and exercise have been shown to improve outcomes, and obesity has been shown to worsen outcomes.” These findings are significant because they give survivors and those looking to prevent breast cancer a way to control risk with everyday choices.
With the past 10 years of progress in breast cancer treatment and research, women facing the disease today have many promising options as therapies become more tailored to particular disease types and are designed to minimize side effects. And with greater understanding of risk factors and preventive lifestyle choices, women are gaining more ways to reduce the risk of diagnosis and recurrence on a daily basis. All in all, it’s progress worth celebrating.
Advances Made, Lives Saved
Two breast cancer survivors share their stories.
Valerie Tabak of Albany, New York, didn’t think her outlook was good when she was diagnosed with Stage IIIB inflammatory breast cancer in 2002. “I left thinking that I was going to be dead,” she says of her reaction to the diagnosis of aggressive disease. And with two children, ages 15 and 20 the time, Valerie was particularly concerned about the prognosis. Her own mother had died of ovarian cancer, so Valerie knew what it was like to lose a parent.
Twelve years later, however, Valerie is in good health. She credits much of her survival to receiving Herceptin for the HER2-positive disease. She says that, at the time, the targeted therapy was given to patients with more-advanced (Stage IV) disease but not to Stage III patients like her. Dr. Chen, who treated Valerie at the Dana-Farber Cancer Institute, recommended that she enroll in a clinical trial using Herceptin in Stage III breast cancer. Now, in addition to seeing her children become young adults, Valerie is helping a friend who is undergoing treatment for inflammatory breast cancer. “It’s really amazing,” she says. “I’ve been the luckiest person.”
When Erin Oian of East Texas was diagnosed with breast cancer at age 29, she was determined to enter her next decade with a clean bill of health. “My one wish for my thirtieth birthday was to be cancer-free,” she says, a goal she met just before she turned 30. “I actually finished my last treatment the day before my thirtieth birthday.”
Because Erin was diagnosed with Stage I invasive ductal carcinoma that was both estrogen receptor–positive and HER2-positive, she received two of the advances highlighted in this article—hormonal therapy and HER2-directed therapy—in addition to a lumpectomy. As hormonal therapy, Erin, who was treated at MD Anderson, received tamoxifen to block the effects of estrogen on cancer growth; she’ll continue to take tamoxifen daily for about three more years. And for HER2-directed therapy, she was given Herceptin.