- What recent progress are you most excited about in breast cancer research?
- The increasing recognition that, while there are distinct features of breast and other cancer types, there are also important areas of overlap and commonality. This means that while we continue to approach breast cancer based on its original site of development (the breast), we can increasingly bring in learnings from other areas of oncology and export some of what we learn as well.
Very specifically, the last few years have enable us to understand one reason that breast cancer runs in some families (the BRCA genes), how specific genes within tumors influence the growth and survival of breast cancers, and how we can attack these potential targets. A particular area of excitement for me and my team has been the application of these scientific advances to the problems of risk and prevention. We are beginning to understand how some known risk factors, such as obesity, cause cancer-promoting signals that we may be able to interrupt. Here we might be treating the risk and abnormalities of normal, not cancer, cells to prevent the disease outright.
- …And in breast cancer treatment?
- Starting with local therapy (surgery and radiation), we now have evidence not only that women with cancer that does not involve their lymph nodes can forego the traditional axillary dissection, but that others with cancer involving a few nodes can similarly avoid this more extensive surgery. Without compromising their cure, this further minimizes the impact of surgery for breast cancer and, along with lumpectomy (breast conservation), limits the functional and cosmetic impact of treatment for the long term.
With regard to the use of drugs to treat and cure disease that may have spread beyond the breast (adjuvant therapy), we again have seen significant new developments, including increased numbers of safer and more effective hormone therapies, increased numbers of ever more effective agents that target HER2 (a protein receptor on the surface of breast cancers in about 20% of women), and clearer guidance on the optimal use of chemotherapy when it is indicated.
In this regard, a particularly important application of the new genetic tools we have developed is the use of a 21-gene test performed on an individual patient’s breast cancer that not only estimates prognosis but specifically guides the use of chemotherapy in addition to hormone therapy. This can sometimes mean that we recommend chemotherapy in situations where we previously did not, but more often it allows us to avoid chemotherapy where it will not be useful. As a consequence, our use of chemotherapy is diminishing somewhat but when we use it the impact is greater.
- What is the first step in early detection?
- A key explanation for the steady fall in deaths from breast cancer since 1990 remains the broadened use of early detection. The best evidence supports the use of mammography. Even though there remain useful scientific debates and discussion about the optimal and most cost-effective use of this tool, we recommend yearly mammography for most women beginning at age 40. This decision should be made in consultation with your physician as there can be specific circumstances that would lead to different recommendations on when to start and to the use of additional and more specialized imaging tests, such as ultrasound or MRI. In addition, there are experimental imaging tests that may be considered within the research setting.
- We are always hearing about how genetics, diet and weight could affect a woman’s chance of getting breast cancer.
What is fact and what is fiction?
- The number one risk for breast cancer is being female and the number two risk is aging. After those are considered, there are additional risk factors such as increased weight, early first period/late menopause, fewer and later pregnancies and others that in some ways reflect real societal success in achieving wide distribution of nutritious foods, low infant mortality, safer pregnancies even later in life and so on. This means that we might not want to reverse some of the underlying trends, even if they confer increased risk. Inheritance of an abnormality of BRCA 1 or 2 or other rarer genes explains a small fraction of breast and other cancers and for patients with those genes, special screening and risk-reducing strategies should be considered. For the average patient without a strong family history and/or a known mutation, the modifiable risk factor that we are most focused on today is weight control.
Rates of obesity are now projected to reach 65% of the U.S. population by 2030 and this is now identified as possibly responsible for up to 20% of the common cancers of adulthood. Caloric restriction and exercise are the two obvious steps that most adult women can take to lower their risks. In addition, there are two FDA-approved drugs (tamoxifen and raloxifene) that are known to reduce the risks of the most common kinds of breast cancer. These drugs have the “side effect” of treating or preventing osteoporosis and their use should be discussed with your physician.
- What is a good source for latest information?
- There are a number of excellent resources, including The Breast Cancer Research Foundation, American Cancer Society and Memorial Sloan-Kettering Cancer Center.
- Three things you want everyone to know…
- The most important things to understand about breast cancer are that it is usually curable (about four out of five women diagnosed with it will not die from it), that treatment and its toxicities are increasingly limited and targeted so that the price for cure is reduced, and that prevention is possible.